The use of cytoplasm male sterility （CMS） is crucial for three-line hybrid seed production. Two types of CMS have been discovered from Dongxiang wild rice, namely the wild abortion type CMS （CMS-WA） and the Dongxi...The use of cytoplasm male sterility （CMS） is crucial for three-line hybrid seed production. Two types of CMS have been discovered from Dongxiang wild rice, namely the wild abortion type CMS （CMS-WA） and the Dongxiang wild type CMS （CMS-DW）. In this study, we show the molecular identification of the two types of CMS in Dongxiang wild rice. WA352, which conferred CMS-WA, was not detected in Dongxiang wild iice, implying Dongxiang wild rice does not carry the CMS- WA source. Further analysis of WA352 in DYIA, a CMS-DW line, by PCR amplification and sequencing, revealed two insertion-deletion polymorphisms occurred in CMS-DW compared to WA352 of CMS-WA. It was reported that WA352 was comprised of an unknown origin sequence and partial sequences of three open reading frames （ORFs）, orf284, orf224 and orf288. The 42-bp insertion was located between the two segments of orf224 and orf288, which created a new chimeric ORF, orf216. This new ORF was also detected in CMS-HL. Based on the 9-bp deletion in orf284, a specific mitochon- drial marker of DW-M1 was developed, which could be used to specifically distinguish the DW-type source. Moreover, semi-quantitative RT-PCR analysis preliminarily suggested that both orf216 and orf284 could be considered as candidates for CMS-DW. These findings present a preliminary understanding of CMS-DW at the molecular level.展开更多
The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food security.H...The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food security.However,the molecular mechanisms underlyingfertility abortion and the restoration of CMs-WA lines remain largely elusive.In this study,we cloned a restorer gene,Rf2o,following a genome-wide association study analysis of the core parent lines of three-line hybrid rice.We found that Rf20 was present in all core parental lines,but different haplotypes and structural variants of its gene resulted in differences in Rf2o expression levels between sterileand restored lines.Rf20 could restorepollen fertility in the CMS-WA line and was found to be responsible for fertility restoration in some CMs lines under high temperatures.In addition,we found that Rf20 encodes a pentatricopeptide repeat protein that competes with WA352 for binding with COX11.This interaction enhances Cox11's function as a scavenger of reactive oxygen species,which in turn restores pollenfertility.Collectively,ourstudysuggestsanewactionmodeforpentatricopeptide repeatproteins inthe fertilityrestorationofCMs lines,providing an essential theoretical basisforbreedingrobustrestorer lines and for overcoming high temperature-induced fertility recovery of some CMS lines.展开更多
基金supported by the National Natural Science Foundation of China (31460343)the Key Program for Science and Technology of Jiangxi Province, China (20152ACF60015)
文摘The use of cytoplasm male sterility （CMS） is crucial for three-line hybrid seed production. Two types of CMS have been discovered from Dongxiang wild rice, namely the wild abortion type CMS （CMS-WA） and the Dongxiang wild type CMS （CMS-DW）. In this study, we show the molecular identification of the two types of CMS in Dongxiang wild rice. WA352, which conferred CMS-WA, was not detected in Dongxiang wild iice, implying Dongxiang wild rice does not carry the CMS- WA source. Further analysis of WA352 in DYIA, a CMS-DW line, by PCR amplification and sequencing, revealed two insertion-deletion polymorphisms occurred in CMS-DW compared to WA352 of CMS-WA. It was reported that WA352 was comprised of an unknown origin sequence and partial sequences of three open reading frames （ORFs）, orf284, orf224 and orf288. The 42-bp insertion was located between the two segments of orf224 and orf288, which created a new chimeric ORF, orf216. This new ORF was also detected in CMS-HL. Based on the 9-bp deletion in orf284, a specific mitochon- drial marker of DW-M1 was developed, which could be used to specifically distinguish the DW-type source. Moreover, semi-quantitative RT-PCR analysis preliminarily suggested that both orf216 and orf284 could be considered as candidates for CMS-DW. These findings present a preliminary understanding of CMS-DW at the molecular level.
基金Biological Breeding-Major Projects(2023ZD04076)National Key Research and Development Project(2022YFD1200800)+1 种基金Hunan Natural Science Foundation(2023JJ30442)Special Funds for the Construction of Innovative Provinces in Hunan Province(2021NK1002).
文摘The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food security.However,the molecular mechanisms underlyingfertility abortion and the restoration of CMs-WA lines remain largely elusive.In this study,we cloned a restorer gene,Rf2o,following a genome-wide association study analysis of the core parent lines of three-line hybrid rice.We found that Rf20 was present in all core parental lines,but different haplotypes and structural variants of its gene resulted in differences in Rf2o expression levels between sterileand restored lines.Rf20 could restorepollen fertility in the CMS-WA line and was found to be responsible for fertility restoration in some CMs lines under high temperatures.In addition,we found that Rf20 encodes a pentatricopeptide repeat protein that competes with WA352 for binding with COX11.This interaction enhances Cox11's function as a scavenger of reactive oxygen species,which in turn restores pollenfertility.Collectively,ourstudysuggestsanewactionmodeforpentatricopeptide repeatproteins inthe fertilityrestorationofCMs lines,providing an essential theoretical basisforbreedingrobustrestorer lines and for overcoming high temperature-induced fertility recovery of some CMS lines.
