Foxtail millet(Setaria italica),a vital drought-resistant crop,plays a significant role in ensuring food and nutritional security.However,its drought resistance mechanism is not fully understood.N6-methyladenosine(m^(...Foxtail millet(Setaria italica),a vital drought-resistant crop,plays a significant role in ensuring food and nutritional security.However,its drought resistance mechanism is not fully understood.N6-methyladenosine(m^(6)A)modification of RNA,a prevalent epi-transcriptomic modification in eukaryotes,provides a binding site for m^(6)A readers and affects plant growth and stress responses by regulating RNA metabolism.In this study,we unveiled that the YT521-B homology(YTH)family gene SiYTH1 positively regulated the drought tolerance of foxtail millet.Notably,the siyth1 mutant exhibited reduced stomatal closure and augmented accumulation of excessive H_(2)O_(2)under drought stress.Further investigations demonstrated that SiYTH1 positively regulated the transcripts harboring m^(6)A modification related to stomatal closure and reactive oxygen species(ROS)scavenging under drought stress.SiYTH1 was uniformly distributed in the cytoplasm of SiYTH1-GFP transgenic foxtail millet.It formed dynamic liquid-like SiYTH1 cytosol condensates in response to drought stress.Moreover,the cytoplasmic protein SiYTH1 was identified as a distinct m^(6)A reader,facilitating the stabilization of its directly bound SiARDP and ROS scavenging-related transcripts under drought stress.Furthermore,natural variation analysis revealed SiYTH1AGTG as the dominant allele responsible for drought tolerance in foxtail millet.Collectively,this study provides novel insights into the intricate mechanism of m^(6)A reader-mediated drought tolerance and presents a valuable genetic resource for improving drought tolerance in foxtail millet breeding.展开更多
基金This work was supported by the National Key R&D Program of China(2023YFD1200700/2023YFD1200702/2018YFD1000700/2018YFD1000704).
文摘Foxtail millet(Setaria italica),a vital drought-resistant crop,plays a significant role in ensuring food and nutritional security.However,its drought resistance mechanism is not fully understood.N6-methyladenosine(m^(6)A)modification of RNA,a prevalent epi-transcriptomic modification in eukaryotes,provides a binding site for m^(6)A readers and affects plant growth and stress responses by regulating RNA metabolism.In this study,we unveiled that the YT521-B homology(YTH)family gene SiYTH1 positively regulated the drought tolerance of foxtail millet.Notably,the siyth1 mutant exhibited reduced stomatal closure and augmented accumulation of excessive H_(2)O_(2)under drought stress.Further investigations demonstrated that SiYTH1 positively regulated the transcripts harboring m^(6)A modification related to stomatal closure and reactive oxygen species(ROS)scavenging under drought stress.SiYTH1 was uniformly distributed in the cytoplasm of SiYTH1-GFP transgenic foxtail millet.It formed dynamic liquid-like SiYTH1 cytosol condensates in response to drought stress.Moreover,the cytoplasmic protein SiYTH1 was identified as a distinct m^(6)A reader,facilitating the stabilization of its directly bound SiARDP and ROS scavenging-related transcripts under drought stress.Furthermore,natural variation analysis revealed SiYTH1AGTG as the dominant allele responsible for drought tolerance in foxtail millet.Collectively,this study provides novel insights into the intricate mechanism of m^(6)A reader-mediated drought tolerance and presents a valuable genetic resource for improving drought tolerance in foxtail millet breeding.
