Project description:Transcriptome profile analysis of young floral buds of fertile and sterile plants from the self-pollinated offspring of the hybrid between novel restorer line NR1 and Nsa CMS line in Brassica napus
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: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:Background: The fertile and sterile plants are derived from the self-pollinated offspring of the F1 hybrid between novel restorer line NR1 and Nsa CMS line in Brassica napus, which possess the identical cytoplasmic genetic material arising from Nsa CMS line. As far as the nuclear genetic background is concerned, both fertile and sterile plants have the complete set of chromosomes from Brassica napus, except one or two members of the added Sinapis arvensis chromosome pair in the fertile plant. To elucidate gene expression and regulation caused by the A and C subgenomes, the alien chromosome and cytoplasm from S. arvensis during the development of young floral buds, we performed genome-widely high-throughput transcriptomic sequencing between young floral buds of sterile and fertile plants. Results: In this study, equal amount of RNA taken from young floral buds of sterile and fertile plants were sequenced using Illumina/Solexa platform. A total of 4,415,866 and 4,244,140 raw tags were obtained in sterile plant (Ste) and fertile plant (Fer) libraries, respectively. After filtering out low quality data, a total of 2,760,574 and 2,714,441 clean tags remained from the two libraries, from which 242,163 (Ste) and 253,507 (Fer) distinct tags were obtained. To identify the genes corresponding to the distinct tags in each library, all distinct sequencing tags were annotated using all possible CATG+17-nt sequences of the genome and transcriptome of Brassica rapa and those of Brassica oleracea as the reference sequences, respectively. Many genes showed substantial differences in expression between the two libraries. In total, there were 3231 genes of B. rapa and 3371 genes of B. oleracea which were detected with significant differential expression levels. GO and pathway-based analyses were performed to determine and further understand the biological functions of differentially expressed genes (DEGs). In addition, there were 1089 specially expressed unknown tags in Fer, which were neither mapped to B. oleracea nor mapped to B. rapa, and these unique tags were presumed to arise basically from the added alien chromosome of S. arvensis. Fifteen genes were randomly selected and confirmed their expression levels by quantitative RT-PCR, fourteen of the fifteen genes showed expression patterns consistent with the digital gene expression (DGE) data. Conclusions: A number of genes were differentially expressed between the young floral buds of sterile and fertile plants. Some of these genes may be candidates for future research on CMS in Nsa line, fertility restoration and improved agronomic traits in NR1 line. Further study of the unknown tags which were specially expressed in Fer will help to dig those genes with desirable agronomic traits from wild species. mRNA profiles of fertile buds (Fer) and sterile buds (Ste) were generated by deep sequencing.
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.