Ghd7 is an important gene involved in the photoperiod flowering pathway in rice.A Ghd7-involved transcriptional regulatory network has been established,but its translational regulatory pathway is poorly understood.The...Ghd7 is an important gene involved in the photoperiod flowering pathway in rice.A Ghd7-involved transcriptional regulatory network has been established,but its translational regulatory pathway is poorly understood.The mutant suppressor of overexpression of Ghd7(sog7)was identified from EMS-induced mutagenesis on the background of ZH11 overexpressing Ghd7.Mut Map analysis revealed that SOG7 is allelic to Ghd8 and delayed flowering under long-day(LD)conditions.Biochemical assays showed that Ghd8 interacts with OsHAP5C and Ghd7 both in vivo and in vitro.Surprisingly,a point mutation E96K in theα2 helix of the Ghd8 histone fold domain(HFD)destroyed its ability to interact with Ghd7.The prediction of the structure shows that mutated amino acid is located in the interaction region of CCT/NF-YB/YC complexes,which alter the structure ofα4 of Ghd8.This structural difference prevents the formation of complex NF-YB/YC.The triple complex of Ghd8-OsHAP5C-Ghd7 directly bound to the promotor of Hd3a and downregulated the expression of Ehd1,Hd3a and RFT1,and finally resulted in a delayed heading.These findings are helpful in deeply understanding the Ghd7-involved photoperiod flowering pathway and promote the elucidation of rice heading.展开更多
Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-5...Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-59-80-2-11-1-10(W32-SSSL) with substituted intervals derived from the donor parents IR66897 B(W31) and IR66167-27-5-1-6(W32), respectively, with Huajingxian 74(HTX74) were found to comprise a gene for extremely late-heading date, and the gene was tentatively designated as Hd-6-2. Two secondary F2 segregating populations were developed by crossing the two heterozygous SSSLs with HJX74 to map Hd-6-2 gene. According to phenotype analysis of the two mapping populations, the late heading date trait was controlled by a major recessive gene. In the segregation population derived from W31-SSSL, Hd-6-2 was mapped on chromosome 6 between PSM677 and RM204 with the genetic distances of 1.3 and 2.7 c M, respectively. In the population of W32-SSSL, the gene for heading date was mapped to the similar region as Hd-6-2 and co-segregated with PSM672. The sequence alignment of Hd3 a in the coding domains and promoter regions of HJX74 and W31-SSSL are completely consistent, whereas there was a great difference between W32-SSSL and HJX74, suggesting that Hd3 a could hardly be the main cause of the heading date variation in W31-SSSL, but it was probably the main reason for the change of heading stage in W32-SSSL.展开更多
Hd3a(Heading date 3a)基因是光周期诱导水稻开花过程中的一个关键调控基因,它在短日条件下表达并促进水稻开花.通过根癌农杆菌介导的方法将热激诱导表达的Hd3a基因转化到水稻品种日本晴中.热激处理转基因植株后,检测结果表明,叶片中转...Hd3a(Heading date 3a)基因是光周期诱导水稻开花过程中的一个关键调控基因,它在短日条件下表达并促进水稻开花.通过根癌农杆菌介导的方法将热激诱导表达的Hd3a基因转化到水稻品种日本晴中.热激处理转基因植株后,检测结果表明,叶片中转基因Hd3a的表达水平比热激前显著提高,随后又下降到热激前的水平,说明转基因Hd3a在水稻中可以被热激诱导瞬间的表达.长日条件下热激转基因水稻可成功诱导其抽穗,而同样处理的野生型植株不能抽穗,表明Hd3a的瞬间表达可诱导水稻开花,且其开花的早晚与热激处理的强度有关.展开更多
基金supported by the Youth Foundation of China(31601283)。
文摘Ghd7 is an important gene involved in the photoperiod flowering pathway in rice.A Ghd7-involved transcriptional regulatory network has been established,but its translational regulatory pathway is poorly understood.The mutant suppressor of overexpression of Ghd7(sog7)was identified from EMS-induced mutagenesis on the background of ZH11 overexpressing Ghd7.Mut Map analysis revealed that SOG7 is allelic to Ghd8 and delayed flowering under long-day(LD)conditions.Biochemical assays showed that Ghd8 interacts with OsHAP5C and Ghd7 both in vivo and in vitro.Surprisingly,a point mutation E96K in theα2 helix of the Ghd8 histone fold domain(HFD)destroyed its ability to interact with Ghd7.The prediction of the structure shows that mutated amino acid is located in the interaction region of CCT/NF-YB/YC complexes,which alter the structure ofα4 of Ghd8.This structural difference prevents the formation of complex NF-YB/YC.The triple complex of Ghd8-OsHAP5C-Ghd7 directly bound to the promotor of Hd3a and downregulated the expression of Ehd1,Hd3a and RFT1,and finally resulted in a delayed heading.These findings are helpful in deeply understanding the Ghd7-involved photoperiod flowering pathway and promote the elucidation of rice heading.
基金financially supported by the National Key Research and Development Program of China (Grant Nos. 2016YFD0100903-9 and 2016YFD0100101-14)the Natural Science Foundation of Shandong Province (Grant No. ZR2014CQ007)the Rice Industry Technology Program of Shandong Province, China (Grant No. SDAIT-17-03)
文摘Heading date is one of the most important traits for rice adaption to different cultivation areas and crop seasons. In this study, two single segment substitution lines(SSSLs), W31-41-61-3-11-3-6-7(W31-SSSL) and W32-59-80-2-11-1-10(W32-SSSL) with substituted intervals derived from the donor parents IR66897 B(W31) and IR66167-27-5-1-6(W32), respectively, with Huajingxian 74(HTX74) were found to comprise a gene for extremely late-heading date, and the gene was tentatively designated as Hd-6-2. Two secondary F2 segregating populations were developed by crossing the two heterozygous SSSLs with HJX74 to map Hd-6-2 gene. According to phenotype analysis of the two mapping populations, the late heading date trait was controlled by a major recessive gene. In the segregation population derived from W31-SSSL, Hd-6-2 was mapped on chromosome 6 between PSM677 and RM204 with the genetic distances of 1.3 and 2.7 c M, respectively. In the population of W32-SSSL, the gene for heading date was mapped to the similar region as Hd-6-2 and co-segregated with PSM672. The sequence alignment of Hd3 a in the coding domains and promoter regions of HJX74 and W31-SSSL are completely consistent, whereas there was a great difference between W32-SSSL and HJX74, suggesting that Hd3 a could hardly be the main cause of the heading date variation in W31-SSSL, but it was probably the main reason for the change of heading stage in W32-SSSL.
文摘Hd3a(Heading date 3a)基因是光周期诱导水稻开花过程中的一个关键调控基因,它在短日条件下表达并促进水稻开花.通过根癌农杆菌介导的方法将热激诱导表达的Hd3a基因转化到水稻品种日本晴中.热激处理转基因植株后,检测结果表明,叶片中转基因Hd3a的表达水平比热激前显著提高,随后又下降到热激前的水平,说明转基因Hd3a在水稻中可以被热激诱导瞬间的表达.长日条件下热激转基因水稻可成功诱导其抽穗,而同样处理的野生型植株不能抽穗,表明Hd3a的瞬间表达可诱导水稻开花,且其开花的早晚与热激处理的强度有关.
