Project description:Using microarray, the anther transcript profiles of the three indica rice CMS lines revealed 622 differentially expression genes (DEGs) in each of the three CMS lines. GO and Mapman analysis indicated that these DEGs were mainly involved in lipid metabolic and cell wall organization. Comprised with the gene expression of sporophytic and gametophytic CMS lines, 303 DEGs were differentially expressed and 56 of them were down-regulated in all the CMS lines. Co-expression network analysis suggested that many genes were significantly differentially expressed in the CMS lines. These down-regulated DEGs in the CMS lines were found to be involved in tapetum or cell wall formation and their suppressed expression might be related to male sterility. The present study will give some information for the nuclear gene regulation by different cytoplasmic genotypes and provide some candidate genes for pollen development in rice.
Project description:The control of mRNA translation has been increasingly recognized as a key regulatory step for gene control but clear examples in eukaryotes are still scarce. Nucleo-cytoplasmic male sterilities (CMS) represent ideal genetic models to dissect genetic interactions between the mitochondria and the nucleus in plants. This trait is determined by specific mitochondrial genes and is associated with a pollen sterility phenotype that can be suppressed by nuclear genes known as restorer-of-fertility (Rf) genes. In the study, we focused on the Ogura CMS system in rapeseed and showed that the suppression to male sterility by the PPR-B fertility restorer (also called Rfo) occurs through a specific inhibition of the translation of the mitochondria-encoded cms-causing mRNA orf138. We also demonstrate that PPR-B binds within the coding sequence of orf138 and acts as a ribosome blocker to specifically impede translation elongation along the orf138 mRNA. Rfo is the first recognized fertility restorer shown to act this way. These observations will certainly facilitate the development of synthetic fertility restorers for CMS systems in which efficient natural Rfs are lacking.
Project description:The control of mRNA translation has been increasingly recognized as a key regulatory step for gene control but clear examples in eukaryotes are still scarce. Nucleo-cytoplasmic male sterilities (CMS) represent ideal genetic models to dissect genetic interactions between the mitochondria and the nucleus in plants. This trait is determined by specific mitochondrial genes and is associated with a pollen sterility phenotype that can be suppressed by nuclear genes known as restorer-of-fertility (Rf) genes. In the study, we focused on the Ogura CMS system in rapeseed and showed that the suppression to male sterility by the PPR-B fertility restorer (also called Rfo) occurs through a specific inhibition of the translation of the mitochondria-encoded cms-causing mRNA orf138. We also demonstrate that PPR-B binds within the coding sequence of orf138 and acts as a ribosome blocker to specifically impede translation elongation along the orf138 mRNA. Rfo is the first recognized fertility restorer shown to act this way. These observations will certainly facilitate the development of synthetic fertility restorers for CMS systems in which efficient natural Rfs are lacking.
Project description:We used a high-throughput proteomics method called label-free to compare protein abundance across a pepper CMS line and its isogenic maintainer line.This study explained the mechanisms of cytoplasmic male sterility and contribute to the improvement of pepper hybrid breeding.
Project description:Background: The use of cytoplasmic male sterility (CMS) in F1 hybrid seed production of chili pepper is increasingly popular. However, the molecular mechanisms of cytoplasmic male sterility and fertility restoration remain poorly understood due to limited transcriptomic and genomic data. Therefore, we analyzed the difference between a CMS line 121A and its near-isogenic restorer line 121C in transcriptome level using next generation sequencing technology (NGS), aiming to find out critical genes and pathways associated with the male sterility. Results: We generated approximately 53 million sequencing reads and assembled de novo, yielding 85,144 high quality unigenes with an average length of 643 bp. Among these unigenes, 27,191 were identified as putative homologs of annotated sequences in the public protein databases, 4,326 and 7,061 unigenes were found to be highly abundant in lines 121A and 121C, respectively. Many of the differentially expressed unigenes represent a set of potential candidate genes associated with the formation or abortion of pollen. Conclusions: Our study profiled anther transcriptomes of a chili pepper CMS line and its restorer line. The results shed the lights on the occurrence and recovery of the disturbances in nuclear-mitochondrial interaction and provide clues for further investigations. Anther transcriptomes of a chili pepper CMS line 121A and its nearisogenic restorer line 121C were generated by deep sequencing, using Illumina HiSeq 2000.
Project description:Temperature-sensitive male sterility is one of the core components for hybrid rice breeding based on two-line system. We previously found that knockout of ARGONAUTE 1d (AGO1d) caused temperature-sensitive male sterility in rice by influencing phased small interfering RNA (phasiRNA) biogenesis and function. However, the specific phasiRNAs and their targets underlying the temperature-sensitive male sterility in ago1d mutant remain to be determined. Here, we demonstrate that the ago1d mutant displays normal female fertility but complete male sterility at low temperature. Through a multi-omics analysis of small RNA, degradome, and transcriptome, we found that 21-nt phasiRNAs account for the greatest proportion of the 21-nt small RNA (sRNA) species in rice anthers and are sensitive to low temperature and markedly down-regulated in ago1d mutant. Moreover, we found that 21-nt phasiRNAs are essential for the mRNA cleavage of a set of fertility- and cold tolerance-associated genes, such as EDT1, TDR, OsPCF5 and OsTCP21, directly or indirectly determined by AGO1d-mediated gene silencing. The loss-of-function of 21-nt phasiRNAs can result in up-regulation of their targets and causes varying degrees of defects in male fertility and grain setting. Our results highlight the essential functions of 21-nt phasiRNAs in temperature-sensitive male sterility in rice and suggest their promising application in two-line hybrid rice breeding in the future.
Project description:Background: The use of cytoplasmic male sterility (CMS) in F1 hybrid seed production of chili pepper is increasingly popular. However, the molecular mechanisms of cytoplasmic male sterility and fertility restoration remain poorly understood due to limited transcriptomic and genomic data. Therefore, we analyzed the difference between a CMS line 121A and its near-isogenic restorer line 121C in transcriptome level using next generation sequencing technology (NGS), aiming to find out critical genes and pathways associated with the male sterility. Results: We generated approximately 53 million sequencing reads and assembled de novo, yielding 85,144 high quality unigenes with an average length of 643 bp. Among these unigenes, 27,191 were identified as putative homologs of annotated sequences in the public protein databases, 4,326 and 7,061 unigenes were found to be highly abundant in lines 121A and 121C, respectively. Many of the differentially expressed unigenes represent a set of potential candidate genes associated with the formation or abortion of pollen. Conclusions: Our study profiled anther transcriptomes of a chili pepper CMS line and its restorer line. The results shed the lights on the occurrence and recovery of the disturbances in nuclear-mitochondrial interaction and provide clues for further investigations.
Project description:Thermosensitive genic male sterile (TGMS) lines and photoperiod-sensitive genic male sterile (PGMS) lines have been successfully used in hybridization to improving rice yields. The molecular mechanisms underlying male sterility transitions in most PGMS/TGMS rice lines are unclear, but in the recently developed TGMS-Co27 lines which is based on co-suppression of a UDP-glucose pyrophosphorylase gene (Ugp1). UGPase protein accumulates in TGMS-Co27 florets at low temperatures and temperature-sensitive splicing is involved in its sterility transitions.However, details of the molecular mechanisms involved are unknown. we use microarrays to compare transcriptomic profiles during the meiosis-stage of flower development in TGMS-Co27 and wild-type (H1493) plants grown at high and low temperatures. The detected differences in expression profiles provide further understanding of the regulatory networks underlying flower development generally, identify genes involved in the TGMS process in TGMS-Co27 and may provide reference data for analyses of molecular mechanisms underlying sterility transitions in other PGMS/TGMS rice lines.
Project description:Male sterility is an important trait in hybrid crop breeding. Thermo-sensitive genic male sterility (TGMS) lines, which are male-sterile at restrictive (high) temperatures but convert to male-fertile at permissive (low) temperatures, have been widely utilized in two-line hybrid rice breeding. However, the molecular mechanism underlying TGMS remains unclear. Here we show that the rice (Oryza sativa L.) thermo-sensitive genic male sterile gene 5 (tms5) locus, which in 2010 was present in cultivars occupying more than 71% (2.3 million hectares) of two-line hybrid rice-growing land in China, confers the TGMS trait through a loss-of-function mutation of RNase ZS1, resulting in failure to mediate mRNA decay of three temperature-responsive ubiquitin fusion ribosomal protein L40 genes (UbL40) genes. RNase ZS1, a member of the evolutionarily conserved endonuclease, processed tRNAs in vitro, but does not do so in vivo due to its localization in the cytoplasm. Defective RNase ZS1 in tms5 plants leads to over-accumulation of UbL401, UbL402 and UbL404 mRNAs at restrictive but not permissive temperatures. Over-expression of UbL401 and UbL404 in wild-type plants caused male sterility, whereas knockdown of UbL401 and UbL404 in tms5 plants partially restored the male fertility at restrictive temperatures. Our results uncover a novel mechanism of RNase ZS1-mediated UbL40 mRNA decay which controls TGMS in rice and has potential applications not only of rice but also of other crops.
Project description:We identified the nup1 mutant rice that exhibited specific male sterility due to the absence of Ubisch body formation and pollen grain production. We cloned the causal gene and demonstrated that NUP1, a class III peroxidase predominantly expressed in the anther wall, mediated ROS scavenging. The loss-of-function of NUP1 resulted in ROS burst in anthers, which disrupted the oxidation-reduction process and carbohydrate and lipid metabolisms, and thereby led to loss of tapetal Ubisch bodies and ultimately resulted in male sterility in rice. Our study expands the understanding of the molecular mechanisms by which ROS homeostasis regulates cell metabolism, tapetal Ubisch body formation and male fertility in plants.