MiR2118-dependent U-rich phasiRNA production in rice anther wall development.
Ontology highlight
ABSTRACT:
SUBMITTER: Araki S
PROVIDER: S-EPMC7305157 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:BackgroundDuring pollen wall formation in flowering plants, a conserved metabolon consisting of acyl-CoA synthetase (ACOS), polyketide synthase (PKS) and tetraketide α-pyrone reductase (TKPR), is required for sporopollenin synthesis. Despite this, the precise function of each of these components in different species remains unclear.ResultsIn this study, we characterized the function of OsTKPR1, a rice orthologue of Arabidopsis TKPR1. Loss of function of OsTKPR1 delayed tapetum degradation, reduced the levels of anther cuticular lipids, and impaired Ubisch body and pollen exine formation, resulting in complete male sterility. In addition, the phenylpropanoid pathway in mutant anthers was remarkably altered. Localization studies suggest that OsTKPR1 accumulates in the endoplasmic reticulum, while specific accumulation of OsTKPR1 mRNA in the anther tapetum and microspores is consistent with its function in anther and pollen wall development.ConclusionsOur results show that OsTKPR1 is indispensable for anther cuticle development and pollen wall formation in rice, providing new insights into the biochemical mechanisms of the conserved sporopollenin metabolon in flowering plants.
| S-EPMC6421701 | biostudies-literature
Project description:Argonaute protein (AGO) in association with small RNAs is the core machinery of RNA silencing, an essential mechanism for precise development and defense against pathogens in many organisms. Here, we identified two AGOs in rice anthers, AGO1b and AGO1d, that interact with phased small interfering RNAs (phasiRNAs) derived from numerous long non-coding RNAs. Moreover, 3D-immunoimaging and mutant analysis indicated that rice AGO1b and AGO1d cell type-specifically regulate anther development by acting as mobile carriers of these phasiRNAs from the somatic cell layers to the germ cells in anthers. Our study also highlights a new mode of reproductive RNA silencing via the specific nuclear and cytoplasmic localization of three AGOs, AGO1b, AGO1d, and MEL1, in rice pollen mother cells.
| S-EPMC10247740 | biostudies-literature
Project description:In flowering plants, ideal male reproductive development requires the systematic coordination of various processes, in which timely differentiation and degradation of the anther wall, especially the tapetum, is essential for both pollen formation and anther dehiscence. Here, we show that OsGPAT3, a conserved glycerol-3-phosphate acyltransferase gene, plays a critical role in regulating anther wall degradation and pollen exine formation. The gpat3-2 mutant had defective synthesis of Ubisch bodies, delayed programmed cell death (PCD) of the inner three anther layers, and abnormal degradation of micropores/pollen grains, resulting in failure of pollen maturation and complete male sterility. Complementation and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) experiments demonstrated that OsGPAT3 is responsible for the male sterility phenotype. Furthermore, the expression level of tapetal PCD-related and nutrient metabolism-related genes changed significantly in the gpat3-2 anthers. Based on these genetic and cytological analyses, OsGPAT3 is proposed to coordinate the differentiation and degradation of the anther wall and pollen grains in addition to regulating lipid biosynthesis. This study provides insights for understanding the function of GPATs in regulating rice male reproductive development, and also lays a theoretical basis for hybrid rice breeding.
| S-EPMC6321289 | biostudies-literature
Project description:In flowering plants, the tapetum, the innermost layer of the anther, provides both nutrient and lipid components to developing microspores, pollen grains, and the pollen coat. Though the programmed cell death of the tapetum is one of the most critical and sensitive steps for fertility and is affected by various environmental stresses, its regulatory mechanisms remain mostly unknown. Here we show that autophagy is required for the metabolic regulation and nutrient supply in anthers and that autophagic degradation within tapetum cells is essential for postmeiotic anther development in rice. Autophagosome-like structures and several vacuole-enclosed lipid bodies were observed in postmeiotic tapetum cells specifically at the uninucleate stage during pollen development, which were completely abolished in a retrotransposon-insertional OsATG7 (autophagy-related 7)-knockout mutant defective in autophagy, suggesting that autophagy is induced in tapetum cells. Surprisingly, the mutant showed complete sporophytic male sterility, failed to accumulate lipidic and starch components in pollen grains at the flowering stage, showed reduced pollen germination activity, and had limited anther dehiscence. Lipidomic analyses suggested impairment of editing of phosphatidylcholines and lipid desaturation in the mutant during pollen maturation. These results indicate a critical involvement of autophagy in a reproductive developmental process of rice, and shed light on the novel autophagy-mediated regulation of lipid metabolism in eukaryotic cells.
| S-EPMC5119067 | biostudies-literature
Project description:Strictosidine synthase (STR) plays an important role in the biosynthesis of terpenoid indole alkaloids (TIAs) and is expressed in a range of active meristematic tissues of higher plants. STR proteins are involved in different physiological and biochemical pathways. However, the function of STR proteins in rice development remains poorly understood. In this study, we identified 21 possible STR-like (OsSTRL) family members in rice genome and found that only one gene, OsSTRL2, exhibited a pre-emergency specific florescence expression pattern. Tissue-specific expression profile analysis, β-glucuronidase histochemical (GUS) staining and RNA in situ hybridization confirmed that OsSTRL2 was highly expressed in tapetal cells and microspores. Comparative protein sequence analysis indicated that OsSTRL2 lacked the key catalytic residue found in a typical STR (STR1), although it possessed conserved β-propellers and α-helices formed the basic structure of STR1. OsSTRL2 knockout mutant resulted to male sterility because of the defects in anther development and pollen wall formation. Subcellular localization of OsSTRL2-YFP revealed that the OsSTRL2 protein was primarily localized in the endoplasmic reticulum (ER). Therefore, OsSTRL2 is an atypical strictosidine synthase that plays crucial roles in regulating anther development and pollen wall formation in rice.
| S-EPMC5537339 | biostudies-literature
Project description:miR319-targeted TCP genes are believed to regulate cell division in leaves and floral organs. However, it remains unknown whether these genes are involved in cell wall development. Here, we report that TCP24 negatively regulates secondary wall thickening in floral organs and roots. The overexpression of the miR319a-resistant version of TCP24 in Arabidopsis disrupted the thickening of secondary cell walls in the anther endothecium, leading to male sterility because of arrested anther dehiscence and pollen release. Several genes linked to secondary cell wall biogenesis and thickening were down-regulated in these transgenic plants. By contrast, the inhibition of TCP24 using the ectopic expression of a TCP24-SRDX repressor fusion protein, or the silencing of TCP genes by miR319a overexpression, increased cell wall lignification and the enhanced secondary cell wall thickening. Our results suggest that TCP24 acts as an important regulator of secondary cell wall thickening and modulates anther endothecium development.
| S-EPMC4478849 | biostudies-literature
Project description:Dissection of the genetic pathways and mechanisms by which anther development occurs in grasses is crucial for both a basic understanding of plant development and for examining traits of agronomic importance such as male sterility. In rice, MULTIPLE SPOROCYTES1 (MSP1), a leucine-rich-repeat receptor kinase, plays an important role in anther development by limiting the number of sporocytes. OsTDL1a (a TPD1-like gene in rice) encodes a small protein that acts as a cofactor of MSP1 in the same regulatory pathway. In this study, we analyzed small RNA and mRNA changes in different stages of spikelets from wild-type rice, and from msp1 and ostdl1a mutants. Analysis of the small RNA data identified miRNAs demonstrating differential abundances. miR2275 was depleted in the two rice mutants; this miRNA is specifically enriched in anthers and functions to trigger the production of 24-nt phased secondary siRNAs (phasiRNAs) from PHAS loci. We observed that the 24-nt phasiRNAs as well as their precursor PHAS mRNAs were also depleted in the two mutants. An analysis of co-expression identified three Argonaute-encoding genes (OsAGO1d, OsAGO2b, and OsAGO18) that accumulate transcripts coordinately with phasiRNAs, suggesting a functional relationship. By mRNA in situ analysis, we demonstrated a strong correlation between the spatiotemporal pattern of these OsAGO transcripts and phasiRNA accumulations.
| S-EPMC5100018 | biostudies-literature
Project description:Gene expression throughout the reproductive process in rice (Oryza sativa) beginning with primordia development through pollination/fertilization to zygote formation was analyzed. We analyzed 25 stages/organs of rice reproductive development including early microsporogenesis stages with 57,381 probe sets, and identified around 26,000 expressed probe sets in each stage. Fine dissection of 25 reproductive stages/organs combined with detailed microarray profiling revealed dramatic, coordinated and finely tuned changes in gene expression. Decrease of expressed genes in the pollen maturation process was observed in a similar way with Arabidopsis and maize. An almost equal number of ab initio predicted genes and cloned genes appeared or disappeared coordinated with developmental stage progression. A large number of organ-/stage-specific genes were identified; notably 2,593 probe sets for developing anther, including 932 probe sets corresponding to ab initio predicted genes. Analysis of cell cycle-related genes revealed that several CDKs, cyclins and components of SCF E3 ubiquitin ligase complexes were expressed specifically in reproductive organs. Cell wall biosynthesis or degradation protein genes and transcription factor genes expressed specifically in reproductive stages were also newly identified. Rice genes homologous to reproduction-related genes in other plants showed expression profiles both consistent and inconsistent with their predicted functions. The rice reproductive expression atlas is likely to be the deepest and most comprehensive dataset available, indispensable for unraveling functions of many specific genes in plant reproductive processes that have not yet been thoroughly analyzed. Keywords: developmental stage comparison, tissue comparison, platform comparison
2010-11-11 | GSE13988 | GEO
Project description:Autophagy has recently been shown to be required for postmeiotic anther development including anther dehiscence, programmed cell death-mediated degradation of the tapetum and pollen maturation in rice. Several phytohormones are known to play essential roles during male reproductive development including pollen maturation. However, the relationship between phytohormone metabolism and autophagy in plant reproductive development is unknown. We here comprehensively analyzed the effect of autophagy disruption on phytohormone contents in rice anthers at the flowering stage, and found that endogenous levels of active-forms of gibberellins (GAs) and cytokinin, trans-zeatin, were significantly lower in the autophagy-defective mutant, Osatg7-1, than in the wild type. Treatment with GA4 partially recovered maturation of the mutant pollens, but did not recover the limited anther dehiscence as well as sterility phenotype. These results suggest that autophagy affects metabolism and endogenous levels of GAs and cytokinin in rice anthers. Reduction in bioactive GAs in the autophagy-deficient mutant may partially explain the defects in pollen maturation of the autophagy-deficient mutant, but tapetal autophagy also plays other specific roles in fertilization.
| S-EPMC5640179 | biostudies-literature
Project description:Gene expression throughout the reproductive process in rice (Oryza sativa) beginning with primordia development through pollination/fertilization to zygote formation was analyzed. We analyzed 25 stages/organs of rice reproductive development including early microsporogenesis stages with 57,381 probe sets, and identified around 26,000 expressed probe sets in each stage. Fine dissection of 25 reproductive stages/organs combined with detailed microarray profiling revealed dramatic, coordinated and finely tuned changes in gene expression. Decrease of expressed genes in the pollen maturation process was observed in a similar way with Arabidopsis and maize. An almost equal number of ab initio predicted genes and cloned genes appeared or disappeared coordinated with developmental stage progression. A large number of organ-/stage-specific genes were identified; notably 2,593 probe sets for developing anther, including 932 probe sets corresponding to ab initio predicted genes. Analysis of cell cycle-related genes revealed that several CDKs, cyclins and components of SCF E3 ubiquitin ligase complexes were expressed specifically in reproductive organs. Cell wall biosynthesis or degradation protein genes and transcription factor genes expressed specifically in reproductive stages were also newly identified. Rice genes homologous to reproduction-related genes in other plants showed expression profiles both consistent and inconsistent with their predicted functions. The rice reproductive expression atlas is likely to be the deepest and most comprehensive dataset available, indispensable for unraveling functions of many specific genes in plant reproductive processes that have not yet been thoroughly analyzed. Keywords: developmental stage comparison, tissue comparison, platform comparison Anther development of rice from hypodermal archesporial cells formation to tri-cellular mature pollens were divided into eight stages. Three or four biological replicates at each stage were analyzed with Affymetrix Rice Genome Array, and total number of samples in this series is 26.
2010-11-11 | E-GEOD-13988 | biostudies-arrayexpress