Grain size is one of the most important factors that control rice yield,as it is associated with grain weight(GW).To date,dozens of rice genes that regulate grain size have been isolated;however,the regulatory mechani...Grain size is one of the most important factors that control rice yield,as it is associated with grain weight(GW).To date,dozens of rice genes that regulate grain size have been isolated;however,the regulatory mechanism underlying GW control is not fully understood.Here,the quantitative trait locus qGL5 for grain length(GL)and GW was identified in recombinant inbred lines of 9311 and Nipponbare(NPB)and fine mapped to a candidate gene,OsAUX3.Sequence variations between 9311 and NPB in the OsAUX3 promoter and loss of function of OsAUX3 led to higher GL and GW.RNA sequencing,gene expression quantification,dual-luciferase reporter assays,chromatin immunoprecipitation-quantitative PCR,and yeast one-hybrid assays demonstrated that OsARF6 is an upstream transcription factor regulating the expression of OsAUX3.OsARF6 binds directly to the auxin response elements of the OsAUX3 promoter,covering a single-nucleotide polymorphism site between 9311 and NPB/Dongjin/Hwayoung,and thereby controls GL by altering longitudinal expansion and auxin distribution/content in glume cells.Furthermore,we showed that miR167a positively regulate GL and GW by directing OsARF6 mRNA silencing.Taken together,our study reveals that a novel miR167a-OsARF6-OsAUX3 module regulates GL and GW in rice,providing a potential target for the improvement of rice yield.展开更多
Grain size and grain weight are important determinants for grain yield.In this study,we identify a novel OsMAPK5–OsWRKY72 module that negatively regulates grain length and grain weight in rice.We found that loss-of-f...Grain size and grain weight are important determinants for grain yield.In this study,we identify a novel OsMAPK5–OsWRKY72 module that negatively regulates grain length and grain weight in rice.We found that loss-of-function of OsMAPK5 leads to larger cell size of the rice spikelet hulls and a significant increase in both grain length and grain weight in an indica variety Minghui 86(MH86).OsMAPK5 interacts with OsMAPKK3/4/5 and OsWRKY72 and phosphorylates OsWRKY72 at T86 and S88.Similar to the osmapk5 MH86 mutants,the oswrky72 knockout MH86 mutants exhibited larger size of spikelet hull cells and increased grain length and grain weight,whereas the OsWRKY72-overexpression MH86 plants showed opposite phenotypes.OsWRKY72 targets the W-box motifs in the promoter of OsARF6,an auxin response factor involved in auxin signaling.Dual-luciferase reporter assays demonstrated that OsWRKY72 activates OsARF6 expression.The activation effect of the phosphorylation-mimicking OsWRKY72T86D/S88D on OsARF6 expression was significantly enhanced,whereas the effects of the OsWRKY72 phosphorylation-null mutants were significantly reduced.In addition,auxin levels in young panicles of the osmapk5 and oswrky72 mutants were significantly higher than that in the wild-type MH86.Collectively,our study uncovered novel connections of the OsMAPKK3/4/5-OsMAPK5-mediated MAPK signaling,OsWRKY72-mediated transcription regulation,and OsARF6-mediated auxin signaling pathways in regulating grain length and grain weight in an indica-type rice,providing promising targets for molecular breeding of rice varieties with high yield and quality.展开更多
基金This project was funded by grants from the National Key Research and Development Program of China(2016YFD0100400)the National Natural Science Foundation of China(32060451)the Zhejiang Provincial Nat-ural Science Foundation of China(grant no.L Z19C020001).
文摘Grain size is one of the most important factors that control rice yield,as it is associated with grain weight(GW).To date,dozens of rice genes that regulate grain size have been isolated;however,the regulatory mechanism underlying GW control is not fully understood.Here,the quantitative trait locus qGL5 for grain length(GL)and GW was identified in recombinant inbred lines of 9311 and Nipponbare(NPB)and fine mapped to a candidate gene,OsAUX3.Sequence variations between 9311 and NPB in the OsAUX3 promoter and loss of function of OsAUX3 led to higher GL and GW.RNA sequencing,gene expression quantification,dual-luciferase reporter assays,chromatin immunoprecipitation-quantitative PCR,and yeast one-hybrid assays demonstrated that OsARF6 is an upstream transcription factor regulating the expression of OsAUX3.OsARF6 binds directly to the auxin response elements of the OsAUX3 promoter,covering a single-nucleotide polymorphism site between 9311 and NPB/Dongjin/Hwayoung,and thereby controls GL by altering longitudinal expansion and auxin distribution/content in glume cells.Furthermore,we showed that miR167a positively regulate GL and GW by directing OsARF6 mRNA silencing.Taken together,our study reveals that a novel miR167a-OsARF6-OsAUX3 module regulates GL and GW in rice,providing a potential target for the improvement of rice yield.
基金funded by grants from Fujian Provincial Science and Technology Key Project(2022NZ030014)National Natural Science Foundation of China(32071941)+1 种基金Natural Science Foundation of Fujian Province(2023J011418)Minjiang University(MJY22023).
文摘Grain size and grain weight are important determinants for grain yield.In this study,we identify a novel OsMAPK5–OsWRKY72 module that negatively regulates grain length and grain weight in rice.We found that loss-of-function of OsMAPK5 leads to larger cell size of the rice spikelet hulls and a significant increase in both grain length and grain weight in an indica variety Minghui 86(MH86).OsMAPK5 interacts with OsMAPKK3/4/5 and OsWRKY72 and phosphorylates OsWRKY72 at T86 and S88.Similar to the osmapk5 MH86 mutants,the oswrky72 knockout MH86 mutants exhibited larger size of spikelet hull cells and increased grain length and grain weight,whereas the OsWRKY72-overexpression MH86 plants showed opposite phenotypes.OsWRKY72 targets the W-box motifs in the promoter of OsARF6,an auxin response factor involved in auxin signaling.Dual-luciferase reporter assays demonstrated that OsWRKY72 activates OsARF6 expression.The activation effect of the phosphorylation-mimicking OsWRKY72T86D/S88D on OsARF6 expression was significantly enhanced,whereas the effects of the OsWRKY72 phosphorylation-null mutants were significantly reduced.In addition,auxin levels in young panicles of the osmapk5 and oswrky72 mutants were significantly higher than that in the wild-type MH86.Collectively,our study uncovered novel connections of the OsMAPKK3/4/5-OsMAPK5-mediated MAPK signaling,OsWRKY72-mediated transcription regulation,and OsARF6-mediated auxin signaling pathways in regulating grain length and grain weight in an indica-type rice,providing promising targets for molecular breeding of rice varieties with high yield and quality.
