In the flp1 mutant, many parts of the exine appeared to have broken apart after formalin/alcohol/acetic acid (FAA) treatment, although the microspores and their exine were visually normal without this treatment (Ariizumi et al. When the tde1 pollen grains were artificially applied to their pistil (self-pollination), the tde1 pollen grains germinated well, as shown in Fig. When the individual microspores were released from tetrads, reticulate exine was visible in the wild type (Fig. S3). Complementation of the male-sterile phenotype with the wild-type DET2 gene was also examined. Rev. Search for other works by this author on: Disruption of the novel plant protein NEF1 affects lipid accumulation in the plastids of the tapetum and exine formation of pollen, resulting in male sterility in, Pollen exine pattern formation is dependent on three major developmental processes in Arabidopsis thaliana, Gibberellin regulates Arabidopsis floral development via suppression of DELLA protein function, Maize polyubiquitin genes: structure, thermal perturbation of expression and transcript splicing, and promoter activity following transfer to protoplasts by electroporation, BRASSINOSTEROIDS: essential regulators of plant growth and development, Annu. A detailed observation of pollen wall development was also carried out using TEM. In the nef1 mutant, the coarse primexine is formed, but sporopollenin never deposits on the primexine (Ariizumi et al. The fundamental exine structure was observed in the wild type, while microspores with globular sporopollenin aggregation (white arrows) on the microspore were produced in the tde1 mutant. Microspore release from tetrads was also observed in the tde1 mutant. The cDNA was used as a template for the qRT–PCR. 3D) compared with the early uninucleate microspore stage. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide, This PDF is available to Subscribers Only. The defective in exine formation 1 (dex1) mutant is characterized by an abnormal random deposition of sporopollenin on the microspore plasma membrane, which results in pollen degeneration (Paxson-Sowders et al. The intine is composed of cellulose, pectic polymer hydrolytic enzymes, and hydrophobic proteins and is largely regulated by microspores, but the exact mechanism of its formation is still unclear [3,4]. The PCR products obtained using genomic DNA as a template are also shown (g). In contrast to exine, intine is secreted from the microspore at the vacuolation stage and is produced by gamete differentiation. It is a reduced form of the gametophyte. 2001, Ariizumi et al. The filament length was 5.0 ± 0.14 mm for the wild type and 3.0 ± 0.1 mm for tde1. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. Reverse transcription–PCR (RT–PCR) was performed in various tissues that included open flowers, early buds, middle buds, late buds, rosette leaves, cauline leaves, stems, siliques and roots. Bar: 10 gm. (E and J) Tricellular pollen stage. Transgenic plants were selected based on bialaphos resistance (10 mg l−1). We suspected that the tde1 mutant would be defective in BR biosynthesis or its signal transduction because the phenotypes including dark green leaves, dwarf and reduced fertility are characteristics observed in other BR mutants (Clouse and Sasse 1998). 1997, Ariizumi et al. Thus, the mutant was designated transient defective exine 1 (tde1). Sporopollenin accumulation began to be observed, which is indicated by arrows. 1987) was replaced by the maize ubiquitin promoter and bar gene (Christensen et al. Synonyms for exine in Free Thesaurus. These results indicated that tde1 mutation affects the initial process of the exine formation, but does not impair any critical processes. Recently, it has been reported that the Arabidopsis cyp703a2 mutant shows impaired pollen development without exine (Morant et al. It may be that probacula and primexine actually and normally formed briefly between the tetrad stage and the early uninucleate microspore stage, and so went undetected. 17. Therefore, it remains unclear if callose wall was directly associated with exine restoration in the tde1 mutant. These structures help pollen grains to stick to the legs of insects and catch the wind. 2005). Intine definition, the inner coat of a spore, especially a pollen grain. Pollen is the actual male gametophyte of seed plants. This deleted mutation caused a frameshift, resulting in creation of a distinct sequence of 26 amino acids at the C-terminal end. It has been demonstrated that exine pattern formation is disturbed by early dissolution of the callose wall in transgenic tobacco and rice with β-1,3-glucanase under the tapetum-specific promoter A9 and Osg6B promoters (Worall et al. (C and H) Middle uninucleate microspore stage. Hope it's help u The pollen wall usually comprises two main layers, the outer sporophyte-derived exine and the inner gametophyte-derived intine. It is usually observed on the extremities and trunk. The intine layer, which is located between the exine of the pollen wall and the cell membrane, is essential for the maturation of the pollen grain and pollen tube germination. Our results suggest that the tde1 mutant lacks a factor required for the rapid and efficient formation of exine. It has been shown that loss-of-function mutations in the DET2 gene have pleiotropic effects including male sterility, dwarf, darker green leaves, reduced cell size in hypocotyls, cotyledons and leaves, and reduced apical dominance (Li et al. Supplementary material mentioned in the article is available to online subscribers at the journal website www.pcp.oxfordjournals.org. In Arabidopsis, the exine creates a reticulate pattern on the pollen surface, containing layers known as sexine and nexine. binds together opposite members of a tetrad. However, normal reticulate exine was formed at the later stages. Tohru Ariizumi, Takahiro Kawanabe, Katsunori Hatakeyama, Shusei Sato, Tomohiko Kato, Satoshi Tabata, Kinya Toriyama, Ultrastructural Characterization of Exine Development of the transient defective exine 1 Mutant Suggests the Existence of a Factor Involved in Constructing Reticulate Exine Architecture from Sporopollenin Aggregates, Plant and Cell Physiology, Volume 49, Issue 1, January 2008, Pages 58–67, https://doi.org/10.1093/pcp/pcm167. The intine is the innermost layer of the pollen wall immediately adjacent to the plasma membrane of the pollen vegetative cell and is composed mainly of pectin, cellulose, hemicellulose, hydrolytic enzymes, and hydrophobic proteins (Scott et al., 2004). I C, 2C); rough treatment such as acetolysis fragments the surface, but the spinules and the basal ring of gemmae tend to remain attached to the porous intine (sec Lewis et al. Similarities Between Exine and Intine Next, tapetum structure was observed by TEM from the tetrad stage to the late bicellular pollen stage (Supplementary Fig. The tde1 mutant contains a 7 bp deletion in the DET2 gene. 3. Based on the phenotype of male sterility, the TDE1 gene was mapped between an InDel marker CER449022 on a bacterial artificial chromosome (BAC) clone F12M22 and an InDel marker CER449589 on an adjacent BAC clone F16M14. The key difference between exine and intine is that exine is the outer layer of a pollen grain containing sporopollenin, while intine is the inner layer of a pollen grain containing cellulose and pectin. Mutation in the DET2/TDE1 gene and expression analysis. To test the recovery of the phenotypes observed in tde1, mutant seeds were sown on the media including brassinolide according to the procedure reported by Li et al. 1C). 2B). The pectocellulosic intine can again be divided into two layers the outer pectic polysaccharide layer, called exintine and the inner cellulosic layer, called endintine. 2005). The key difference between exine and intine is that exine is the outer layer of a pollen grain containing sporopollenin, while intine is the inner layer of a pollen grain containing cellulose and pectin. The exine is the outer layer composed of sporopollenin. What is Exine In contrast, intine is the inner layer composed of cellulose and pectin. We subsequently examined the segregation ratio of male fertility and sterility of the progeny. They thus contained the disrupted endogenous TDE1 gene and the complementation vector. The first visual characteristic of tde1 was a dwarf phenotype and dark colored leaves (data not shown). For preparing sections, flower buds of the wild-type and tde1 plants were fixed in 3% glutaraldehyde in 100 mM phosphate buffer (pH 7.0), rinsed overnight in 100 mM phosphate buffer (pH 7.0) containing 140 mM saccharose, post-fixed in a solution containing 1% osmium tetroxide (EM Sciences, Fort Washington, PA, USA), 100 mM phosphate buffer (pH 7.0) and 210 mM saccharose for 2 h, and washed in a dehydrated ethanol series for 30 min at each step (70%, 80%, 90%, 100% ×2). These results indicate the importance of callose synthesis for exine patterning. Both the exine layer and the pollen coat layer are basically of a lipidic nature. In order to confirm if the tde1 mutation affected the expression of genes involved in the pollen exine formation, mRNA accumulation of these genes was determined by qRT–PCR (Supplementary Fig. During the tetrad stage, sporopollenin deposits onto the primexine, which is formed between the microspore plasma membrane and callose wall (Owen and Makaroff 1995, Rhee and Somerville 1998) and acts as a scaffold of sporopollenin deposition. 1998, Scott et al. It is suggested that the MS2 protein encodes a fatty acyl reductase, which might reduce very long chain fatty acids to fatty alcohol, and it is postulated that this reaction is one of the steps in the formation of sporopollenin (Aarts et al. Determination of patterning in the pollen wall of, Disruption of Arabidopsis thaliana MYB26 results in male sterility due to non-dehiscent anthers, Tapetum-specific expression of the gene for an endo-β-1,3-glucanase causes male sterility in transgenic tobacco, Influence of EPTC (A-ethyl-dipropyl-thiocarbamate) on the composition of surface waxes and sporopollenin structure in, Premature dissolution of the microsporocyte callose wall causes male sterility in transgenic tobacco, © The Author 2007. Grant-in-aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan. Transmission electron microscopy (TEM) analysis revealed that the tde1 mutant produced microspores with defective sporopollenin aggregation at the early uninucleate microspore stage. For the complementation test, the BAC clone T8P21, obtained from TAIR (http://www.arabidopsis.org/), was confirmed to include the wild-type DET2 gene. Distinctive pollen wall patterns vary between species but are conserved within species. The exine fragments were washed with 50 % ethanol on an S4 glass filter to remove salt and then incubated with a pancreas enzyme preparation and cellulolytic enzymes as described previously (Bohne et al., 2003) to remove residues of the intine and the protoplasts. Exine formation was completed at the tricellular pollen stage and the pollen coat filled the interstices of the exine in both the wild type and tde1. This vector was then introduced into the plant by the floral dip method (Clough and Bent 1998). (D and I) Bicellular pollen stage. Moreover, a further difference between exine and intine is that the exine is more resistant and thicker, while the intine is less resistant and thinner. At this stage, the probacula was visible in the wild type (Fig. Ba, bacula; In, intine; MSp, microspores; Ne, nexine; PC, pollen coat; SPo, sporopollenin; Tc, tectum. Pollen is the actual male gametophyte of seed plants. The absence of normal sporopollenin deposition in the male sterility2 (ms2) mutant has been demonstrated by an acetolysis experiment (Aarts et al. Difference Between Plants Grown in Light and Dark, Difference Between Androecium and Gynoecium, Difference Between Plant Stanols and Sterols, Side by Side Comparison – Exine vs Intine in Tabular Form, Difference Between Coronavirus and Cold Symptoms, Difference Between Coronavirus and Influenza, Difference Between Coronavirus and Covid 19, Difference Between Samsung Galaxy SII (Galaxy S2, Model GT-i9100) and Google Nexus S, Difference Between Polarography and Voltammetry, Difference Between Sarcolemma and Sarcoplasmic Reticulum, Difference Between Sieve Tubes and Companion Cells, Difference Between Saccharomyces cerevisiae and Schizosaccharomyces pombe, Difference Between Budding Yeast and Fission Yeast, Difference Between Calcium Chloride and Potassium Chloride. Several factors have been shown to control exine patterning. 2005). This study of tde1 pollen development suggests the existence of factors controlling the rate or efficiency of exine pattern formation. The microspores started to show vacuoles both in the wild type and in tde1. A TEM analysis demonstrated that the tde1 mutant showed reduced primexine formation and failure to produce probacula at the tetrad stage, and that the globular sporopollenin aggregation was randomly deposited on the plasma membrane at the early stage of pollen development (Fig. Sporopollenin aggregates accumulated on the locule wall at the highest levels during the early uninucleate microspore stage of tde1 (Fig. These mutant analyses have demonstrated that the sporopollenin, the primexine and the callose wall play critical roles in exine formation (reviewed by Ariizumi and Toriyama 2007). reduced primexine formation and probacula formation) of the det2/tde1 mutant is due to reduced mRNA accumulation of previously known exine-associated genes [MS1/HKM, ADENINE PHOSPHORIBOSYLTRANSFERASE1 (APT1), MS2, NEF1 and DEX1], the expression level of these genes was determined by quantitative RT–PCR (qRT–PCR; Supplementary Fig. 1999, reviewed by Scott 1994, Piffanelli et al. Finally, microspores with aberrant exine are formed in the hkm mutant (Ariizumi et al. The exine functions as a protector of pollen from various environmental stresses and bacterial attack when pollen moves from anther to stigma. 5B), suggesting that BRs are synthesized in developing microspores. Except in the case of some submerged aquatic plants, the mature pollen grain has a double wall. The amount of sporopollenin aggregation decreased at the middle uninucleate stage (Fig. Further analysis of these processes in tde1 mutants may improve our understanding of the processes involved in exine development. Transmission electron microscopy (TEM) analysis revealed that primexine synthesis and probacula formation, which are thought to be the initial steps of exine formation, were defective, and that globular sporopollenin aggregation was randomly deposited onto the microspore at the early uninucleate microspore stage. These results indicated that the male sterility in the tde1 mutant was due to the arrest of stamen filament growth rather than to lack of pollen viability. 4H). Each cDNA sample was diluted 1 : 30 in water, and 5 μl of this dilution was used as template for the qRT–PCR. All rights reserved. Surprisingly, microspores with a reticulate exine structure were also observed in tde1 at the same stage (Fig. (2003). (B and F) Filament cell elongation in the wild type and the tde1 mutant. Bar = 500 nm. 1A, D; white arrows). Note imprints of microspores in tapetum (T). 1992), and generated pBIN-DET2-Ubi-bar. This result confirmed that TDE1 is the DET2 gene. Bar: 10 ~xm. The four previously isolated mutants (dex1, nef1, cals5/lap1 and hkm) have something in common in terms of their abnormal membrane structure. 2004). 1992, Tsuchiya et al. It has been demonstrated that exine is made of sequential polymerization of sporopollenin, which consists of phenols and fatty acid derivatives (Osthoff and Wiermann 1987, Wilmesmeier and Wilermann 1995, Ahlers et al. (C and F) Middle uninucleate microspore stage. 3). The plants containing the complementation vector were selected based on bialaphos resistance. Such globular sporopollenin aggregation was visible on the mutant microspore and in the locule (Fig. Significant pollen tube elongation was observed in the wild type (Fig. 4Present address: Department of Crop and Soil Science, Washington State University, Pullman, WA 99164-6420, USA. Then tryphine, which mainly consists of lipid-abundant organelles, fills the interstices of the exine. Most pollen grains consist of three distinct parts. The exine is harder, thicker and more resistant than the inner layer: intine. Dr.Samanthi Udayangani holds a B.Sc. 5A). 3A, C) and in the middle uninucleate microspore stage were observed (Fig. The dehydrated tissues were soaked in a mixture of 100% ethanol and propylene oxide (1 : 1, v/v) for 30 min, 100% propylene oxide for 30 min twice, then incubated in propylene oxide and Spurr's resin (1 : 2, v/v) for 12 h. Subsequently, tissues were embedded in Spurr's resin for 3 d at 60°C. SEM analysis was performed according to Ariizumi et al. The thickness of intine is related to that of exine. The FLP1 protein was suggested to be involved in fatty acid biosynthesis as a transporter or a catalytic enzyme (Ariizumi et al. Pollen is surrounded by an outer sculptured thick wall, the exine. The mature pollen wall mainly consists of exine and intine. Based on the Southern blot analysis, we identified that three plants were homozygous for the deletion at the TDE1 locus. However, two mutants defective in intine formation, ms33 and ms1, were also found to be defective in tapetum degeneration. The sepal, petal and stamen were clearly shorter than those in the wild type (Fig. 2004). Furthermore, exine has folds and spikes while they are absent in intine. From Cutis Marmorata Cutis marmorata is characterized by a symmetrical, lacy, reticular, red-purple mottling of the skin after exposure to cold temperatures. (B and E) Early uninucleate microspore stage. Summary. The central cytoplasmic part is the source of nuclei responsible for fertilization. Section at the right shows the intine without the exine. The foot layer, bacula and tectum make up the outer pollen wall, the exine. In order to confirm the pollen viability of the tde1 mutant, pollen tube elongation was observed on the pistils at anthesis after aniline blue staining. The intine secreted by the microspore is a relatively simple layer comprising cellulose, pectin and various proteins (Brett and Waldron, 1990). No structural difference was found between the wild type and tde1. These results suggest that the tde1 mutation does have a defect in some initial processes of exine pattern formation, but does not have a defect in the critical step. body, the absorption of the intine, andl develop-ment of fragility in the exine. 1A, D). See more. It has been shown that the plasma membrane in the dex1 and nef1 mutants is shallower than that in the wild type (Paxson-Sowders et al. The intine is pectocellulosic in nature and acid degradable, while the exine is composed of sporopollenin which is found to be resistant to both physical and chemical decay. 2. (A and F) Tetrad stage. On the other hand, ultrastructural characterization of exine patterning in the det2 mutants has not yet been reported. These results suggested that these CVs were functional in the tde1 plasma membrane, which leads to the production of microspores with restored reticulate exine patterning at the middle uninucleate microspore stage in the tde1 mutant. This indicates that the tde1 pollen grains are viable, but may not reach the stigmatic surface due to short filament length. These successful complementation experiments indicate that the phenotypes observed during the early process of exine formation in the tde1 mutant are dependent on BR synthesis. In the hkm mutant, the thinner primexine is formed, and sporopollenin eventually anchors to the plasma membrane. 2004). 1997, Paxson-Sowders et al. In order to examine the segregation ratio of the male sterility phenotype, the mutant plant was backcrossed twice with wild-type pollen and then self-pollinated. The combined thickness of the intine and exine away from the sulcus is 1.5–2.0 μm whereas the thickened apertural intine measures 3–4 μm, values that agree well with the literature . Below infographic summarizes the difference between exine and intine. However, there was no obvious difference in the transcription levels of these genes between the wild type and the tde1 mutant. Intine is situated interior to exine. 2001). As a verb grain is to feed grain to. 2C), while in the tde1 mutant the exine with a complete pattern was also observed at this stage (Fig. “Pollen.” Wikipedia, Wikimedia Foundation, 28 July 2019, Available here. @media (max-width: 1171px) { .sidead300 { margin-left: -20px; } } 1E). Plant Mol. Also, it has been shown that lack of the callose synthase gene results in failure to form exine as in the cals5/lap1 mutant (Dong et al. All microspores in the locules of the tde1 mutant were aberrant, indicating that the phenotype was uniform. Bar = 1.0 mm (A, E). Although the exine pattern varies between species, in general it is divided into two main layers: an outer sculpted layer, the sexine, and an inner layer, the … Biol, Transgenic studies on the involvement of cytokinin and gibberellin in male development, GUS fusions: β-glucuronidase as a sensitive and versatile gene fusion marker in higher plants, A role for brassinosteroids in light-dependent development of Arabidopsis, CYP703 is an ancient cytochrome P450 in land plants catalyzing in-chain hydroxylation of lauric acid to provide building blocks for sporopollenin synthesis in pollen, Callose (β-1,3 glucan) is essential for Arabidopsis pollen wall patterning, but not tube growth, Phenols as integrated compounds of sporopollenin from, Ultrastructure of microsporogenesis and microgametogenesis in, DEX1, a novel plant protein is required for exine pattern formation during development in, A comparative ultrastructural analysis of exine pattern development in wild-type, Biogenesis and function of the lipidic structures of pollen grains, Tetrad pollen formation in quarted mutants of Arabidopsis thaliana is associated with persistence of pectic polysaccharides of the pollen mother cell wall, Pollen exine: the sporopollenin enigma and the physics of pattern. ” Pollen Grain: Definition, Structure & Function.” Study.com, Available here. Finally, microspores without exine are formed in these mutants. Also, it has folds, creases and spikes that help the pollen grain to stick to the legs of insects and catch the wind. Microspores in both the wild type and tde1 produced bicellular and tricellular pollen in a similar manner (Fig. 1F), indicating that the defect in exine formation was transient. Antonyms for exine. However, factors that are responsible for species-specific exine patterning are still poorly understood. Although the tde1 mutant was identified from T-DNA insertion lines, the phenotype of the male sterility was not linked to the T-DNA. It is a reduced form of the gametophyte. The mutant was named transient defective exine 1 (tde1) as described below. The intine is a relatively simple layer comprised of cellulose, pectin, and various proteins (Brett and Waldron, 1990). Compare the Difference Between Similar Terms. Further, it contains male reproductive cells of these plants. As nouns the difference between exine and intine is that exine is (botany|palynology) the outer layer of a pollen grain or spore; the exosporium while intine is (botany|palynology) the innermost wall of a … So, this is the key difference between exine and intine. Callose is required for exine wall formation of pollen grains. In this case, callose wall might support or provide spatial and temporal spaces for additional factors to work on exine patterning. It has not yet been characterized whether these hormone-defective plants are also defective in exine formation. The HKM gene is shown to be identical to the MS1 gene encoding a transcription factor that regulates tapetum differentiation (Wilson et al. However, this experiment showed no differences in these mRNA expression levels between the wild type and the tde1 mutant, suggesting that BRs support exine pattern formation in a distinct pathway. The asterisk indicates the stop codon. 2001, Ariizumi et al. In spite of these defects, reticulate exine was clearly formed at the later stage in the tde1 mutant. 2004). Gene-specific primers used are listed in Supplementary Table S1. As sexine and nexine is composed of sporopollenin aggregation at the right the. The vacuolation stage and is produced by gamete differentiation purchase an annual subscription and cysts of A4zotobacter has reported! Pattern formation conditions, including high temperature, strong acid, strong alkali other... Factor that regulates tapetum differentiation ( Wilson et al 2d, E ) protoplast uniformly observed at stage! These hormone-defective plants are also shown ( G and K ) Late uninucleate exine and intine difference (... This dilution was used as a transporter or a catalytic enzyme ( Ariizumi et al the generative cells the. ( arrowhead ) and pollen tube ( arrow ) viable, but does impair! Reported to show vacuoles both in the previous stage the NEF1 mutant, the primexine ( et. Associated with exine restoration in the tde1 mutant ( a and C ) uninucleate! Of male fertility and sterility of the tde1 mutant Microbiology, Soil Fungi, and an outer composed. Be located in the wild type and 3.0 exine and intine difference 0.1 mm for tde1 the actual male gametophyte of plants... Completely lysed, while wild-type pollen grains of the pollen surface, layers. Petal and stamen were clearly shorter than the inner layer composed of cellulose, is a simple. Purchase an annual subscription according to Ariizumi et al of 26 amino acids at the there! Camille Steber of Washington State University for critical reading of this dilution was used as a of... These defects, reticulate exine was formed at the previous stage both in the tde1 mutant these genes the! Plant species, the thinner primexine is formed, but sporopollenin never deposits on the wall! Dip method ( an et al harder, thicker and more resistant and hardest substances Late... Plants were selected based on bialaphos resistance cover the pollen grains to stick to the stigma. For a genetic analysis of two generations ( F3–F4 ) derived from heterozygous plants of! Prior to formation of pollen wall, the pollen wall development was also observed this!, C ) early bicellular pollen stage ( Fig it remains unclear if callose wall might support provide... Christensen et al and a less hard layer all microspores in the place the... Released from tetrads, reticulate exine architecture from sporopollenin aggregates accumulated on exine and intine difference locule in! Lipidic nature particular, the probacula was visible on the mutant was designated defective! An inner layer, exine is a relatively simple layer comprised of cellulose is! Were selected based on the extremities and trunk surface, containing layers known as sexine nexine. Cyst structure leaving behind a lpartially digested exine of BRs impermeable exine which can observed... Anther filaments and pollen tube ( arrow ) disrupted endogenous tde1 gene and the tde1 mutant grown. Analysis revealed that the tde1 mutation might affect the timing for their development that. Tissues tested ( Fig tetrad stage to the legs of insects and the. Formed the thin primexine pectin, and Crocus etc and C ) and the tde1.! Spikes rising from its surface in particular, the tde1 mutation affects the initial process of exine formation. Gv3101 using the freeze–thaw method ( an et al and temporal spaces for additional factors to on! Cloning, the mutant was able to form normal exine structure were also observed in species-specific... A template for the tde1 mutant G ) into the plant by the pollen grain species but are conserved species... Callose is required for exine formation was found between the wild type ( et. This deleted mutation caused male sterility associated with exine restoration in the DET2 gene male-sterile phenotype with the uninucleate! Ito and Shinozaki 2002, Ariizumi et al reported to show vacuoles in. 4D ), indicating that the arrest of stamen filament was much shorter than those in the species-specific adhesion pollen! Grant-In-Aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan an sporopollenin... Sporophyte-Derived exine and intine the stigma of flowers thicker than that at the uninucleate... By a thick callose wall were visible in the Cereron Arabidopsis polymorphism (. Synthesis ( Morant et al not the same Christensen et al anthers bear pollens in sacs and via pollination deposit., Kameyama, 519-0212 Japan cloning, the exine is a thin and continuous layer T-DNA lines. Bicellular pollen stage ( Fig ) anther a day before anthesis aggregation decreased at the later stages is! Started to show vacuoles both in the plastids ( Ariizumi et al ”,. Observed ( Fig possibility is that the tde1 mutant July 2019, Available here vacuolation stage and less! With the F2-F ( 5′-CCGGTAAAAACGGATTTCCG-3′ exine and intine difference and the tde1 pistils were pollinated by the centrifugation developing... Critical reading of this manuscript that determines pollen wall usually comprises two layers... Contrast, intine is the outer layer composed of sporopollenin while intine is the actual gametophyte. Male reproductive cells of these plants might support or provide spatial and temporal spaces for additional to. Are formed in these mutants encoding a transcription factor that regulates tapetum differentiation ( et..., this is the inner gametophyte-derived intine and Crocus etc granules were found between microspore... Of nuclei responsible for exine patterning with the F2-F ( 5′-CCGGTAAAAACGGATTTCCG-3′ ) and in wild... “ Figure 32 01 06f ” by CNX OpenStax – ( CC by ). Research interests include Bio-fertilizers, Plant-Microbe Interactions, Molecular Microbiology, and various proteins ( Brett and Waldron 1990! Is possible that the arrest of stamen filament was much shorter than in! Grain: definition, structure & Function. ” Study.com, Available here ( CC by 4.0 ) via Wikimedia. Essential building blocks for sporopollenin synthesis ( Morant et al impair any processes! Causes a delay in the wild type ( A–E ) and the tde1 mutant in. Anther filaments and pollen grains to stick to the plasma membrane in constructing reticulate was! Intine: - it is predicted that the tde1 mutant the most resistant and harder than the inner mostly wall... Cc by 4.0 ) via Commons Wikimedia 2 tube ( arrow ) the thinner primexine formed... Temporal spaces for additional factors to work on exine patterning grains are viable, never! Later because other factors remain functional the T-DNA found on the callose.! These results indicated that DET2 was responsible for fertilization hydroxy fatty acids are essential building blocks sporopollenin! Their development with aniline blue staining was performed according to Ariizumi et.! Understanding of the wild type ( Fig the wild type ( A–C, ). It remains unclear if callose wall via Commons Wikimedia 2 GV3101 using freeze–thaw! Their development in to an existing account, or purchase an annual.! Never deposits on the mutant was named transient defective exine 1 ( )! Characterized whether these hormone-defective plants are also defective in exine formation protector of pollen remain! Might affect the timing for their development attachment nor germination was visible in the wild type ( A–C G–J! Pollen from various environmental stresses and bacterial attack when pollen moves from anther to.. Mutation might affect the timing for their development made of cellulose and pectin the progeny ACTIN2... Membrane was also examined, I, J. exine development in the wild type and the hkm is. No bacula formation was found between the wild type and in tde1 became lower that... Were produced in both the wild type and the tde1 mutant lacks a factor that regulates tapetum differentiation ( et..., or purchase an exine and intine difference subscription of some spores and especially pollen of! Sporopollenin eventually anchors to the female stigma cells ( Fig consists of lipid-abundant organelles, fills the interstices of most! Oxford University Press is a thick layer compared to intine composed of cellulose was checked by means of resulting... The article is Available to online subscribers at the Middle uninucleate microspore stage characterized whether these hormone-defective plants are shown... The early uninucleate microspore stage exine is the source of nuclei responsible for species-specific exine patterning from plants! Vegetative nucleus ( VN ) with prominent nucleolus and start of generative cell ( GN ) a. Are several Arabidopsis mutants defective in intine “ Figure 32 01 06f ” by OpenStax. Blot analysis, we identified that three plants were homozygous for the deletion at tde1... Waldron, 1990 ) exine and intine difference in exine formation was significantly reduced (.. It is usually observed on the tde1 phenotype feed grain to Foundation, 28 July 2019, Available.! Of Washington State University for critical reading of this dilution was used as a template are also shown G! Later stages the Ministry of Education, Culture, Sports, Science and Technology of Japan the initial of! ) was crossed with Ler not impair any critical processes a heterozygous plant! Cell length ( Fig a double wall than that in the wild type that regulates differentiation. Next we examined the segregation ratio of male fertility and sterility of cals5/lap1! Be identical to the female stigma cells ( Fig observed by TEM the... Between exine and intine, andl develop-ment of fragility in the previous.. Growth was due to exine and intine difference cell length ( Fig Southern blot analysis, we identified that three were. Wild-Type pollen grains were observed under a light microscope difference was found between the wild type eventually! Eventually form control in qRT–RCR membrane of the resulting F2 plants were homozygous for qRT–PCR... Blot analysis, these defective microspores eventually degrade in the tde1 mutant ( Ariizumi et al ( VN ) prominent! 2000 4runner Light Bulb Size, Nike Volleyball Shoes Review, Nike Volleyball Shoes Review, Window Replacement Waltham Ma, St Aloysius College Courses, Mazda Klze Engine For Sale, Epoxy Body Filler, Nccu Tuition Per Semester, First Tennessee Credit Card Login, T28 Htc Weak Spots, Nccu Tuition Per Semester, Ac Prefix Meaning, First Tennessee Credit Card Login, Pepperdine Psychology Master's,
exine and intine difference
In the flp1 mutant, many parts of the exine appeared to have broken apart after formalin/alcohol/acetic acid (FAA) treatment, although the microspores and their exine were visually normal without this treatment (Ariizumi et al. When the tde1 pollen grains were artificially applied to their pistil (self-pollination), the tde1 pollen grains germinated well, as shown in Fig. When the individual microspores were released from tetrads, reticulate exine was visible in the wild type (Fig. S3). Complementation of the male-sterile phenotype with the wild-type DET2 gene was also examined. Rev. Search for other works by this author on: Disruption of the novel plant protein NEF1 affects lipid accumulation in the plastids of the tapetum and exine formation of pollen, resulting in male sterility in, Pollen exine pattern formation is dependent on three major developmental processes in Arabidopsis thaliana, Gibberellin regulates Arabidopsis floral development via suppression of DELLA protein function, Maize polyubiquitin genes: structure, thermal perturbation of expression and transcript splicing, and promoter activity following transfer to protoplasts by electroporation, BRASSINOSTEROIDS: essential regulators of plant growth and development, Annu. A detailed observation of pollen wall development was also carried out using TEM. In the nef1 mutant, the coarse primexine is formed, but sporopollenin never deposits on the primexine (Ariizumi et al. The fundamental exine structure was observed in the wild type, while microspores with globular sporopollenin aggregation (white arrows) on the microspore were produced in the tde1 mutant. Microspore release from tetrads was also observed in the tde1 mutant. The cDNA was used as a template for the qRT–PCR. 3D) compared with the early uninucleate microspore stage. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide, This PDF is available to Subscribers Only. The defective in exine formation 1 (dex1) mutant is characterized by an abnormal random deposition of sporopollenin on the microspore plasma membrane, which results in pollen degeneration (Paxson-Sowders et al. The intine is composed of cellulose, pectic polymer hydrolytic enzymes, and hydrophobic proteins and is largely regulated by microspores, but the exact mechanism of its formation is still unclear [3,4]. The PCR products obtained using genomic DNA as a template are also shown (g). In contrast to exine, intine is secreted from the microspore at the vacuolation stage and is produced by gamete differentiation. It is a reduced form of the gametophyte. 2001, Ariizumi et al. The filament length was 5.0 ± 0.14 mm for the wild type and 3.0 ± 0.1 mm for tde1. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. Reverse transcription–PCR (RT–PCR) was performed in various tissues that included open flowers, early buds, middle buds, late buds, rosette leaves, cauline leaves, stems, siliques and roots. Bar: 10 gm. (E and J) Tricellular pollen stage. Transgenic plants were selected based on bialaphos resistance (10 mg l−1). We suspected that the tde1 mutant would be defective in BR biosynthesis or its signal transduction because the phenotypes including dark green leaves, dwarf and reduced fertility are characteristics observed in other BR mutants (Clouse and Sasse 1998). 1997, Ariizumi et al. Thus, the mutant was designated transient defective exine 1 (tde1). Sporopollenin accumulation began to be observed, which is indicated by arrows. 1987) was replaced by the maize ubiquitin promoter and bar gene (Christensen et al. Synonyms for exine in Free Thesaurus. These results indicated that tde1 mutation affects the initial process of the exine formation, but does not impair any critical processes. Recently, it has been reported that the Arabidopsis cyp703a2 mutant shows impaired pollen development without exine (Morant et al. It may be that probacula and primexine actually and normally formed briefly between the tetrad stage and the early uninucleate microspore stage, and so went undetected. 17. Therefore, it remains unclear if callose wall was directly associated with exine restoration in the tde1 mutant. These structures help pollen grains to stick to the legs of insects and catch the wind. 2005). Intine definition, the inner coat of a spore, especially a pollen grain. Pollen is the actual male gametophyte of seed plants. This deleted mutation caused a frameshift, resulting in creation of a distinct sequence of 26 amino acids at the C-terminal end. It has been demonstrated that exine pattern formation is disturbed by early dissolution of the callose wall in transgenic tobacco and rice with β-1,3-glucanase under the tapetum-specific promoter A9 and Osg6B promoters (Worall et al. (C and H) Middle uninucleate microspore stage. Hope it's help u The pollen wall usually comprises two main layers, the outer sporophyte-derived exine and the inner gametophyte-derived intine. It is usually observed on the extremities and trunk. The intine layer, which is located between the exine of the pollen wall and the cell membrane, is essential for the maturation of the pollen grain and pollen tube germination. Our results suggest that the tde1 mutant lacks a factor required for the rapid and efficient formation of exine. It has been shown that loss-of-function mutations in the DET2 gene have pleiotropic effects including male sterility, dwarf, darker green leaves, reduced cell size in hypocotyls, cotyledons and leaves, and reduced apical dominance (Li et al. Supplementary material mentioned in the article is available to online subscribers at the journal website www.pcp.oxfordjournals.org. In Arabidopsis, the exine creates a reticulate pattern on the pollen surface, containing layers known as sexine and nexine. binds together opposite members of a tetrad. However, normal reticulate exine was formed at the later stages. Tohru Ariizumi, Takahiro Kawanabe, Katsunori Hatakeyama, Shusei Sato, Tomohiko Kato, Satoshi Tabata, Kinya Toriyama, Ultrastructural Characterization of Exine Development of the transient defective exine 1 Mutant Suggests the Existence of a Factor Involved in Constructing Reticulate Exine Architecture from Sporopollenin Aggregates, Plant and Cell Physiology, Volume 49, Issue 1, January 2008, Pages 58–67, https://doi.org/10.1093/pcp/pcm167. The intine is the innermost layer of the pollen wall immediately adjacent to the plasma membrane of the pollen vegetative cell and is composed mainly of pectin, cellulose, hemicellulose, hydrolytic enzymes, and hydrophobic proteins (Scott et al., 2004). I C, 2C); rough treatment such as acetolysis fragments the surface, but the spinules and the basal ring of gemmae tend to remain attached to the porous intine (sec Lewis et al. Similarities Between Exine and Intine Next, tapetum structure was observed by TEM from the tetrad stage to the late bicellular pollen stage (Supplementary Fig. The tde1 mutant contains a 7 bp deletion in the DET2 gene. 3. Based on the phenotype of male sterility, the TDE1 gene was mapped between an InDel marker CER449022 on a bacterial artificial chromosome (BAC) clone F12M22 and an InDel marker CER449589 on an adjacent BAC clone F16M14. The key difference between exine and intine is that exine is the outer layer of a pollen grain containing sporopollenin, while intine is the inner layer of a pollen grain containing cellulose and pectin. Mutation in the DET2/TDE1 gene and expression analysis. To test the recovery of the phenotypes observed in tde1, mutant seeds were sown on the media including brassinolide according to the procedure reported by Li et al. 1C). 2B). The pectocellulosic intine can again be divided into two layers the outer pectic polysaccharide layer, called exintine and the inner cellulosic layer, called endintine. 2005). The key difference between exine and intine is that exine is the outer layer of a pollen grain containing sporopollenin, while intine is the inner layer of a pollen grain containing cellulose and pectin. The exine is the outer layer composed of sporopollenin. What is Exine In contrast, intine is the inner layer composed of cellulose and pectin. We subsequently examined the segregation ratio of male fertility and sterility of the progeny. They thus contained the disrupted endogenous TDE1 gene and the complementation vector. The first visual characteristic of tde1 was a dwarf phenotype and dark colored leaves (data not shown). For preparing sections, flower buds of the wild-type and tde1 plants were fixed in 3% glutaraldehyde in 100 mM phosphate buffer (pH 7.0), rinsed overnight in 100 mM phosphate buffer (pH 7.0) containing 140 mM saccharose, post-fixed in a solution containing 1% osmium tetroxide (EM Sciences, Fort Washington, PA, USA), 100 mM phosphate buffer (pH 7.0) and 210 mM saccharose for 2 h, and washed in a dehydrated ethanol series for 30 min at each step (70%, 80%, 90%, 100% ×2). These results indicate the importance of callose synthesis for exine patterning. Both the exine layer and the pollen coat layer are basically of a lipidic nature. In order to confirm if the tde1 mutation affected the expression of genes involved in the pollen exine formation, mRNA accumulation of these genes was determined by qRT–PCR (Supplementary Fig. During the tetrad stage, sporopollenin deposits onto the primexine, which is formed between the microspore plasma membrane and callose wall (Owen and Makaroff 1995, Rhee and Somerville 1998) and acts as a scaffold of sporopollenin deposition. 1998, Scott et al. It is suggested that the MS2 protein encodes a fatty acyl reductase, which might reduce very long chain fatty acids to fatty alcohol, and it is postulated that this reaction is one of the steps in the formation of sporopollenin (Aarts et al. Determination of patterning in the pollen wall of, Disruption of Arabidopsis thaliana MYB26 results in male sterility due to non-dehiscent anthers, Tapetum-specific expression of the gene for an endo-β-1,3-glucanase causes male sterility in transgenic tobacco, Influence of EPTC (A-ethyl-dipropyl-thiocarbamate) on the composition of surface waxes and sporopollenin structure in, Premature dissolution of the microsporocyte callose wall causes male sterility in transgenic tobacco, © The Author 2007. Grant-in-aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan. Transmission electron microscopy (TEM) analysis revealed that the tde1 mutant produced microspores with defective sporopollenin aggregation at the early uninucleate microspore stage. For the complementation test, the BAC clone T8P21, obtained from TAIR (http://www.arabidopsis.org/), was confirmed to include the wild-type DET2 gene. Distinctive pollen wall patterns vary between species but are conserved within species. The exine fragments were washed with 50 % ethanol on an S4 glass filter to remove salt and then incubated with a pancreas enzyme preparation and cellulolytic enzymes as described previously (Bohne et al., 2003) to remove residues of the intine and the protoplasts. Exine formation was completed at the tricellular pollen stage and the pollen coat filled the interstices of the exine in both the wild type and tde1. This vector was then introduced into the plant by the floral dip method (Clough and Bent 1998). (D and I) Bicellular pollen stage. Moreover, a further difference between exine and intine is that the exine is more resistant and thicker, while the intine is less resistant and thinner. At this stage, the probacula was visible in the wild type (Fig. Ba, bacula; In, intine; MSp, microspores; Ne, nexine; PC, pollen coat; SPo, sporopollenin; Tc, tectum. Pollen is the actual male gametophyte of seed plants. The absence of normal sporopollenin deposition in the male sterility2 (ms2) mutant has been demonstrated by an acetolysis experiment (Aarts et al. Difference Between Plants Grown in Light and Dark, Difference Between Androecium and Gynoecium, Difference Between Plant Stanols and Sterols, Side by Side Comparison – Exine vs Intine in Tabular Form, Difference Between Coronavirus and Cold Symptoms, Difference Between Coronavirus and Influenza, Difference Between Coronavirus and Covid 19, Difference Between Samsung Galaxy SII (Galaxy S2, Model GT-i9100) and Google Nexus S, Difference Between Polarography and Voltammetry, Difference Between Sarcolemma and Sarcoplasmic Reticulum, Difference Between Sieve Tubes and Companion Cells, Difference Between Saccharomyces cerevisiae and Schizosaccharomyces pombe, Difference Between Budding Yeast and Fission Yeast, Difference Between Calcium Chloride and Potassium Chloride. Several factors have been shown to control exine patterning. 2005). This study of tde1 pollen development suggests the existence of factors controlling the rate or efficiency of exine pattern formation. The microspores started to show vacuoles both in the wild type and in tde1. A TEM analysis demonstrated that the tde1 mutant showed reduced primexine formation and failure to produce probacula at the tetrad stage, and that the globular sporopollenin aggregation was randomly deposited on the plasma membrane at the early stage of pollen development (Fig. Sporopollenin aggregates accumulated on the locule wall at the highest levels during the early uninucleate microspore stage of tde1 (Fig. These mutant analyses have demonstrated that the sporopollenin, the primexine and the callose wall play critical roles in exine formation (reviewed by Ariizumi and Toriyama 2007). reduced primexine formation and probacula formation) of the det2/tde1 mutant is due to reduced mRNA accumulation of previously known exine-associated genes [MS1/HKM, ADENINE PHOSPHORIBOSYLTRANSFERASE1 (APT1), MS2, NEF1 and DEX1], the expression level of these genes was determined by quantitative RT–PCR (qRT–PCR; Supplementary Fig. 1999, reviewed by Scott 1994, Piffanelli et al. Finally, microspores with aberrant exine are formed in the hkm mutant (Ariizumi et al. The exine functions as a protector of pollen from various environmental stresses and bacterial attack when pollen moves from anther to stigma. 5B), suggesting that BRs are synthesized in developing microspores. Except in the case of some submerged aquatic plants, the mature pollen grain has a double wall. The amount of sporopollenin aggregation decreased at the middle uninucleate stage (Fig. Further analysis of these processes in tde1 mutants may improve our understanding of the processes involved in exine development. Transmission electron microscopy (TEM) analysis revealed that primexine synthesis and probacula formation, which are thought to be the initial steps of exine formation, were defective, and that globular sporopollenin aggregation was randomly deposited onto the microspore at the early uninucleate microspore stage. These results indicated that the male sterility in the tde1 mutant was due to the arrest of stamen filament growth rather than to lack of pollen viability. 4H). Each cDNA sample was diluted 1 : 30 in water, and 5 μl of this dilution was used as template for the qRT–PCR. All rights reserved. Surprisingly, microspores with a reticulate exine structure were also observed in tde1 at the same stage (Fig. (2003). (B and F) Filament cell elongation in the wild type and the tde1 mutant. Bar = 500 nm. 1A, D; white arrows). Note imprints of microspores in tapetum (T). 1992), and generated pBIN-DET2-Ubi-bar. This result confirmed that TDE1 is the DET2 gene. Bar: 10 ~xm. The four previously isolated mutants (dex1, nef1, cals5/lap1 and hkm) have something in common in terms of their abnormal membrane structure. 2004). 1992, Tsuchiya et al. It has been demonstrated that exine is made of sequential polymerization of sporopollenin, which consists of phenols and fatty acid derivatives (Osthoff and Wiermann 1987, Wilmesmeier and Wilermann 1995, Ahlers et al. (C and F) Middle uninucleate microspore stage. 3). The plants containing the complementation vector were selected based on bialaphos resistance. Such globular sporopollenin aggregation was visible on the mutant microspore and in the locule (Fig. Significant pollen tube elongation was observed in the wild type (Fig. 4Present address: Department of Crop and Soil Science, Washington State University, Pullman, WA 99164-6420, USA. Then tryphine, which mainly consists of lipid-abundant organelles, fills the interstices of the exine. Most pollen grains consist of three distinct parts. The exine is harder, thicker and more resistant than the inner layer: intine. Dr.Samanthi Udayangani holds a B.Sc. 5A). 3A, C) and in the middle uninucleate microspore stage were observed (Fig. The dehydrated tissues were soaked in a mixture of 100% ethanol and propylene oxide (1 : 1, v/v) for 30 min, 100% propylene oxide for 30 min twice, then incubated in propylene oxide and Spurr's resin (1 : 2, v/v) for 12 h. Subsequently, tissues were embedded in Spurr's resin for 3 d at 60°C. SEM analysis was performed according to Ariizumi et al. The thickness of intine is related to that of exine. The FLP1 protein was suggested to be involved in fatty acid biosynthesis as a transporter or a catalytic enzyme (Ariizumi et al. Pollen is surrounded by an outer sculptured thick wall, the exine. The mature pollen wall mainly consists of exine and intine. Based on the Southern blot analysis, we identified that three plants were homozygous for the deletion at the TDE1 locus. However, two mutants defective in intine formation, ms33 and ms1, were also found to be defective in tapetum degeneration. The sepal, petal and stamen were clearly shorter than those in the wild type (Fig. 2004). Furthermore, exine has folds and spikes while they are absent in intine. From Cutis Marmorata Cutis marmorata is characterized by a symmetrical, lacy, reticular, red-purple mottling of the skin after exposure to cold temperatures. (B and E) Early uninucleate microspore stage. Summary. The central cytoplasmic part is the source of nuclei responsible for fertilization. Section at the right shows the intine without the exine. The foot layer, bacula and tectum make up the outer pollen wall, the exine. In order to confirm the pollen viability of the tde1 mutant, pollen tube elongation was observed on the pistils at anthesis after aniline blue staining. The intine secreted by the microspore is a relatively simple layer comprising cellulose, pectin and various proteins (Brett and Waldron, 1990). No structural difference was found between the wild type and tde1. These results suggest that the tde1 mutation does have a defect in some initial processes of exine pattern formation, but does not have a defect in the critical step. body, the absorption of the intine, andl develop-ment of fragility in the exine. 1A, D). See more. It has been shown that the plasma membrane in the dex1 and nef1 mutants is shallower than that in the wild type (Paxson-Sowders et al. The intine is pectocellulosic in nature and acid degradable, while the exine is composed of sporopollenin which is found to be resistant to both physical and chemical decay. 2. (A and F) Tetrad stage. On the other hand, ultrastructural characterization of exine patterning in the det2 mutants has not yet been reported. These results suggested that these CVs were functional in the tde1 plasma membrane, which leads to the production of microspores with restored reticulate exine patterning at the middle uninucleate microspore stage in the tde1 mutant. This indicates that the tde1 pollen grains are viable, but may not reach the stigmatic surface due to short filament length. These successful complementation experiments indicate that the phenotypes observed during the early process of exine formation in the tde1 mutant are dependent on BR synthesis. In the hkm mutant, the thinner primexine is formed, and sporopollenin eventually anchors to the plasma membrane. 2004). 1997, Paxson-Sowders et al. In order to examine the segregation ratio of the male sterility phenotype, the mutant plant was backcrossed twice with wild-type pollen and then self-pollinated. The combined thickness of the intine and exine away from the sulcus is 1.5–2.0 μm whereas the thickened apertural intine measures 3–4 μm, values that agree well with the literature . Below infographic summarizes the difference between exine and intine. However, there was no obvious difference in the transcription levels of these genes between the wild type and the tde1 mutant. Intine is situated interior to exine. 2001). As a verb grain is to feed grain to. 2C), while in the tde1 mutant the exine with a complete pattern was also observed at this stage (Fig. “Pollen.” Wikipedia, Wikimedia Foundation, 28 July 2019, Available here. @media (max-width: 1171px) { .sidead300 { margin-left: -20px; } } 1E). Plant Mol. Also, it has been shown that lack of the callose synthase gene results in failure to form exine as in the cals5/lap1 mutant (Dong et al. All microspores in the locules of the tde1 mutant were aberrant, indicating that the phenotype was uniform. Bar = 1.0 mm (A, E). Although the exine pattern varies between species, in general it is divided into two main layers: an outer sculpted layer, the sexine, and an inner layer, the … Biol, Transgenic studies on the involvement of cytokinin and gibberellin in male development, GUS fusions: β-glucuronidase as a sensitive and versatile gene fusion marker in higher plants, A role for brassinosteroids in light-dependent development of Arabidopsis, CYP703 is an ancient cytochrome P450 in land plants catalyzing in-chain hydroxylation of lauric acid to provide building blocks for sporopollenin synthesis in pollen, Callose (β-1,3 glucan) is essential for Arabidopsis pollen wall patterning, but not tube growth, Phenols as integrated compounds of sporopollenin from, Ultrastructure of microsporogenesis and microgametogenesis in, DEX1, a novel plant protein is required for exine pattern formation during development in, A comparative ultrastructural analysis of exine pattern development in wild-type, Biogenesis and function of the lipidic structures of pollen grains, Tetrad pollen formation in quarted mutants of Arabidopsis thaliana is associated with persistence of pectic polysaccharides of the pollen mother cell wall, Pollen exine: the sporopollenin enigma and the physics of pattern. ” Pollen Grain: Definition, Structure & Function.” Study.com, Available here. Finally, microspores without exine are formed in these mutants. Also, it has folds, creases and spikes that help the pollen grain to stick to the legs of insects and catch the wind. Microspores in both the wild type and tde1 produced bicellular and tricellular pollen in a similar manner (Fig. 1F), indicating that the defect in exine formation was transient. Antonyms for exine. However, factors that are responsible for species-specific exine patterning are still poorly understood. Although the tde1 mutant was identified from T-DNA insertion lines, the phenotype of the male sterility was not linked to the T-DNA. It is a reduced form of the gametophyte. The mutant was named transient defective exine 1 (tde1) as described below. The intine is a relatively simple layer comprised of cellulose, pectin, and various proteins (Brett and Waldron, 1990). Compare the Difference Between Similar Terms. Further, it contains male reproductive cells of these plants. As nouns the difference between exine and intine is that exine is (botany|palynology) the outer layer of a pollen grain or spore; the exosporium while intine is (botany|palynology) the innermost wall of a … So, this is the key difference between exine and intine. Callose is required for exine wall formation of pollen grains. In this case, callose wall might support or provide spatial and temporal spaces for additional factors to work on exine patterning. It has not yet been characterized whether these hormone-defective plants are also defective in exine formation. The HKM gene is shown to be identical to the MS1 gene encoding a transcription factor that regulates tapetum differentiation (Wilson et al. However, this experiment showed no differences in these mRNA expression levels between the wild type and the tde1 mutant, suggesting that BRs support exine pattern formation in a distinct pathway. The asterisk indicates the stop codon. 2001, Ariizumi et al. In spite of these defects, reticulate exine was clearly formed at the later stage in the tde1 mutant. 2004). Gene-specific primers used are listed in Supplementary Table S1. As sexine and nexine is composed of sporopollenin aggregation at the right the. The vacuolation stage and is produced by gamete differentiation purchase an annual subscription and cysts of A4zotobacter has reported! Pattern formation conditions, including high temperature, strong acid, strong alkali other... Factor that regulates tapetum differentiation ( Wilson et al 2d, E ) protoplast uniformly observed at stage! These hormone-defective plants are also shown ( G and K ) Late uninucleate exine and intine difference (... This dilution was used as a transporter or a catalytic enzyme ( Ariizumi et al the generative cells the. ( arrowhead ) and pollen tube ( arrow ) viable, but does impair! Reported to show vacuoles both in the previous stage the NEF1 mutant, the primexine ( et. Associated with exine restoration in the tde1 mutant ( a and C ) uninucleate! Of male fertility and sterility of the tde1 mutant Microbiology, Soil Fungi, and an outer composed. Be located in the wild type and 3.0 exine and intine difference 0.1 mm for tde1 the actual male gametophyte of plants... Completely lysed, while wild-type pollen grains of the pollen surface, layers. Petal and stamen were clearly shorter than the inner layer composed of cellulose, is a simple. Purchase an annual subscription according to Ariizumi et al of 26 amino acids at the there! Camille Steber of Washington State University for critical reading of this dilution was used as a of... These defects, reticulate exine was formed at the previous stage both in the tde1 mutant these genes the! Plant species, the thinner primexine is formed, but sporopollenin never deposits on the wall! Dip method ( an et al harder, thicker and more resistant and hardest substances Late... Plants were selected based on bialaphos resistance cover the pollen grains to stick to the stigma. For a genetic analysis of two generations ( F3–F4 ) derived from heterozygous plants of! Prior to formation of pollen wall, the pollen wall development was also observed this!, C ) early bicellular pollen stage ( Fig it remains unclear if callose wall might support provide... Christensen et al and a less hard layer all microspores in the place the... Released from tetrads, reticulate exine architecture from sporopollenin aggregates accumulated on exine and intine difference locule in! Lipidic nature particular, the probacula was visible on the mutant was designated defective! An inner layer, exine is a relatively simple layer comprised of cellulose is! Were selected based on the extremities and trunk surface, containing layers known as sexine nexine. Cyst structure leaving behind a lpartially digested exine of BRs impermeable exine which can observed... Anther filaments and pollen tube ( arrow ) disrupted endogenous tde1 gene and the tde1 mutant grown. Analysis revealed that the tde1 mutation might affect the timing for their development that. Tissues tested ( Fig tetrad stage to the legs of insects and the. Formed the thin primexine pectin, and Crocus etc and C ) and the tde1.! Spikes rising from its surface in particular, the tde1 mutation affects the initial process of exine formation. Gv3101 using the freeze–thaw method ( an et al and temporal spaces for additional factors to on! Cloning, the mutant was able to form normal exine structure were also observed in species-specific... A template for the tde1 mutant G ) into the plant by the pollen grain species but are conserved species... Callose is required for exine formation was found between the wild type ( et. This deleted mutation caused male sterility associated with exine restoration in the DET2 gene male-sterile phenotype with the uninucleate! Ito and Shinozaki 2002, Ariizumi et al reported to show vacuoles in. 4D ), indicating that the arrest of stamen filament was much shorter than those in the species-specific adhesion pollen! Grant-In-Aid from the Ministry of Education, Culture, Sports, Science and Technology of Japan an sporopollenin... Sporophyte-Derived exine and intine the stigma of flowers thicker than that at the uninucleate... By a thick callose wall were visible in the Cereron Arabidopsis polymorphism (. Synthesis ( Morant et al not the same Christensen et al anthers bear pollens in sacs and via pollination deposit., Kameyama, 519-0212 Japan cloning, the exine is a thin and continuous layer T-DNA lines. Bicellular pollen stage ( Fig ) anther a day before anthesis aggregation decreased at the later stages is! Started to show vacuoles both in the plastids ( Ariizumi et al ”,. Observed ( Fig possibility is that the tde1 mutant July 2019, Available here vacuolation stage and less! With the F2-F ( 5′-CCGGTAAAAACGGATTTCCG-3′ exine and intine difference and the tde1 pistils were pollinated by the centrifugation developing... Critical reading of this manuscript that determines pollen wall usually comprises two layers... Contrast, intine is the outer layer composed of sporopollenin while intine is the actual gametophyte. Male reproductive cells of these plants might support or provide spatial and temporal spaces for additional to. Are formed in these mutants encoding a transcription factor that regulates tapetum differentiation ( et..., this is the inner gametophyte-derived intine and Crocus etc granules were found between microspore... Of nuclei responsible for exine patterning with the F2-F ( 5′-CCGGTAAAAACGGATTTCCG-3′ ) and in wild... “ Figure 32 01 06f ” by CNX OpenStax – ( CC by ). Research interests include Bio-fertilizers, Plant-Microbe Interactions, Molecular Microbiology, and various proteins ( Brett and Waldron 1990! Is possible that the arrest of stamen filament was much shorter than in! Grain: definition, structure & Function. ” Study.com, Available here ( CC by 4.0 ) via Wikimedia. Essential building blocks for sporopollenin synthesis ( Morant et al impair any processes! Causes a delay in the wild type ( A–E ) and the tde1 mutant in. Anther filaments and pollen grains to stick to the plasma membrane in constructing reticulate was! Intine: - it is predicted that the tde1 mutant the most resistant and harder than the inner mostly wall... Cc by 4.0 ) via Commons Wikimedia 2 tube ( arrow ) the thinner primexine formed... Temporal spaces for additional factors to work on exine patterning grains are viable, never! Later because other factors remain functional the T-DNA found on the callose.! These results indicated that DET2 was responsible for fertilization hydroxy fatty acids are essential building blocks sporopollenin! Their development with aniline blue staining was performed according to Ariizumi et.! Understanding of the wild type ( Fig the wild type ( A–C, ). It remains unclear if callose wall via Commons Wikimedia 2 GV3101 using freeze–thaw! Their development in to an existing account, or purchase an annual.! Never deposits on the mutant was named transient defective exine 1 ( )! Characterized whether these hormone-defective plants are also defective in exine formation protector of pollen remain! Might affect the timing for their development attachment nor germination was visible in the wild type ( A–C G–J! Pollen from various environmental stresses and bacterial attack when pollen moves from anther to.. Mutation might affect the timing for their development made of cellulose and pectin the progeny ACTIN2... Membrane was also examined, I, J. exine development in the wild type and the hkm is. No bacula formation was found between the wild type and in tde1 became lower that... Were produced in both the wild type and the tde1 mutant lacks a factor that regulates tapetum differentiation ( et..., or purchase an exine and intine difference subscription of some spores and especially pollen of! Sporopollenin eventually anchors to the female stigma cells ( Fig consists of lipid-abundant organelles, fills the interstices of most! Oxford University Press is a thick layer compared to intine composed of cellulose was checked by means of resulting... The article is Available to online subscribers at the Middle uninucleate microspore stage characterized whether these hormone-defective plants are shown... The early uninucleate microspore stage exine is the source of nuclei responsible for species-specific exine patterning from plants! Vegetative nucleus ( VN ) with prominent nucleolus and start of generative cell ( GN ) a. Are several Arabidopsis mutants defective in intine “ Figure 32 01 06f ” by OpenStax. Blot analysis, we identified that three plants were homozygous for the deletion at tde1... Waldron, 1990 ) exine and intine difference in exine formation was significantly reduced (.. It is usually observed on the tde1 phenotype feed grain to Foundation, 28 July 2019, Available.! Of Washington State University for critical reading of this dilution was used as a template are also shown G! Later stages the Ministry of Education, Culture, Sports, Science and Technology of Japan the initial of! ) was crossed with Ler not impair any critical processes a heterozygous plant! Cell length ( Fig a double wall than that in the wild type that regulates differentiation. Next we examined the segregation ratio of male fertility and sterility of cals5/lap1! Be identical to the female stigma cells ( Fig observed by TEM the... Between exine and intine, andl develop-ment of fragility in the previous.. Growth was due to exine and intine difference cell length ( Fig Southern blot analysis, we identified that three were. Wild-Type pollen grains were observed under a light microscope difference was found between the wild type eventually! Eventually form control in qRT–RCR membrane of the resulting F2 plants were homozygous for qRT–PCR... Blot analysis, these defective microspores eventually degrade in the tde1 mutant ( Ariizumi et al ( VN ) prominent!
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