CONSTANS,CO-like,and TOC1(CCT)family genes play important roles in regulating heading date,which exerts a large impact on the regional and seasonal adaptation of rice.Previous studies have shown that Grain number,plan...CONSTANS,CO-like,and TOC1(CCT)family genes play important roles in regulating heading date,which exerts a large impact on the regional and seasonal adaptation of rice.Previous studies have shown that Grain number,plant height,and heading date2(Ghd2)exhibits a negative response to drought stress by directly upregulating Rubisco activase and exerting a negative effect on heading date.However,the target gene of Ghd2 regulating heading date is still unknown.In this study,CO3 is identified by analyzing Ghd2 ChIP-seq data.Ghd2 activates CO3 expression by binding to the CO3 promoter through its CCT domain.EMSA experiments show that the motif CCACTA in the CO3 promoter was recognized by Ghd2.A comparison of the heading dates among plants with CO3 knocked out or overexpressed and double-mutants with Ghd2 overexpressed and CO3 knocked out shows that CO3 negatively and constantly regulates flowering by repressing the transcription of Ehd1,Hd3a,and RFT1.In addition,the target genes of CO3 are explored via a comprehensive analysis of DAP-seq and RNA-seq data.Taken together,these results suggest that Ghd2 directly binds to the downstream gene CO3,and the Ghd2eCO3 module constantly delays heading date via the Ehd1-mediated pathway.展开更多
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
基金supported by the Natural Science Foundation of China(U20A2031)the Earmarked Fund for China Agricultural Research System(CARS-01).
文摘CONSTANS,CO-like,and TOC1(CCT)family genes play important roles in regulating heading date,which exerts a large impact on the regional and seasonal adaptation of rice.Previous studies have shown that Grain number,plant height,and heading date2(Ghd2)exhibits a negative response to drought stress by directly upregulating Rubisco activase and exerting a negative effect on heading date.However,the target gene of Ghd2 regulating heading date is still unknown.In this study,CO3 is identified by analyzing Ghd2 ChIP-seq data.Ghd2 activates CO3 expression by binding to the CO3 promoter through its CCT domain.EMSA experiments show that the motif CCACTA in the CO3 promoter was recognized by Ghd2.A comparison of the heading dates among plants with CO3 knocked out or overexpressed and double-mutants with Ghd2 overexpressed and CO3 knocked out shows that CO3 negatively and constantly regulates flowering by repressing the transcription of Ehd1,Hd3a,and RFT1.In addition,the target genes of CO3 are explored via a comprehensive analysis of DAP-seq and RNA-seq data.Taken together,these results suggest that Ghd2 directly binds to the downstream gene CO3,and the Ghd2eCO3 module constantly delays heading date via the Ehd1-mediated pathway.
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.
