Heading date and photoperiod sensitivity are fundamental traits that determine rice adaptation to a wide range of geographic environments. By quantitative trait locus （QTL） mapping and candidate gene analysis using ...Heading date and photoperiod sensitivity are fundamental traits that determine rice adaptation to a wide range of geographic environments. By quantitative trait locus （QTL） mapping and candidate gene analysis using whole- genome re-sequencing, we found that Oryza sativa Pseudo-Response Regulator37 （OsPRR37; hereafter PRR37） is respon- sible for the Early heading7-2 （EH7-2）/Heading date2 （Hd2） QTL which was identified from a cross of late-heading rice ＇Milyang23 （M23）＇ and early-heading rice ＇H143＇. H143 contains a missense mutation of an invariantly conserved amino acid in the CCT （CONSTANS, CO-like, and TOC1） domain of PRR37 protein. In the world rice collection, different types of nonfunctional PRR37 alleles were found in many European and Asian rice cultivars. Notably, the japonica varieties harboring nonfunctional alleles of both Ghd7/Hd4 and PRR37/Hd2 flower extremely early under natural long-day condi- tions, and are adapted to the northernmost regions of rice cultivation, up to 53~ N latitude. Genetic analysis revealed that the effects of PRR37 and Ghd7 alleles on heading date are additive, and PRR37 down-regulates Hd3a expression to suppress flowering under long-day conditions. Our results demonstrate that natural variations in PRR37/Hd2 and GhdT/ Hd4 have contributed to the expansion of rice cultivation to temperate and cooler regions.展开更多
Photosynthesis,which provides oxygen and energy for all living organisms,is circadian regulated.Photosynthesis-associated metabolism must tightly coordinate with the circadian clock to maximize the efficiency of the l...Photosynthesis,which provides oxygen and energy for all living organisms,is circadian regulated.Photosynthesis-associated metabolism must tightly coordinate with the circadian clock to maximize the efficiency of the light-energy capture and carbon fixation.However,the molecular basis for the interplay of photosynthesis and the circadian clock is not fully understood,particularly in crop plants.Here,we report two central oscillator genes of circadian clock,OsPRR95 and OsPRR59 in rice,which function as transcriptional repressors to negatively regulate the rhythmic expression of OsMGT3 encoding a chloroplast-localized Mg2+transporter.OsMGT3-dependent rhythmic Mg fluctuations modulate carbon fixation and consequent sugar output in rice chloroplasts.Furthermore,sugar triggers the increase of superoxide,which may act as a feedback signal to positively regulate the expression of OsPRR95 and OsPRR59.Taken together,our results reveal a negative-feedback loop that strengthens the crosstalk between photosynthetic carbon fixation and the circadian clock,which may improve plan adaptation and performance in fluctuating environments.展开更多
文摘Heading date and photoperiod sensitivity are fundamental traits that determine rice adaptation to a wide range of geographic environments. By quantitative trait locus （QTL） mapping and candidate gene analysis using whole- genome re-sequencing, we found that Oryza sativa Pseudo-Response Regulator37 （OsPRR37; hereafter PRR37） is respon- sible for the Early heading7-2 （EH7-2）/Heading date2 （Hd2） QTL which was identified from a cross of late-heading rice ＇Milyang23 （M23）＇ and early-heading rice ＇H143＇. H143 contains a missense mutation of an invariantly conserved amino acid in the CCT （CONSTANS, CO-like, and TOC1） domain of PRR37 protein. In the world rice collection, different types of nonfunctional PRR37 alleles were found in many European and Asian rice cultivars. Notably, the japonica varieties harboring nonfunctional alleles of both Ghd7/Hd4 and PRR37/Hd2 flower extremely early under natural long-day condi- tions, and are adapted to the northernmost regions of rice cultivation, up to 53~ N latitude. Genetic analysis revealed that the effects of PRR37 and Ghd7 alleles on heading date are additive, and PRR37 down-regulates Hd3a expression to suppress flowering under long-day conditions. Our results demonstrate that natural variations in PRR37/Hd2 and GhdT/ Hd4 have contributed to the expansion of rice cultivation to temperate and cooler regions.
基金the National Nat-ural Science Foundation of China(nos.32022077 and 31872171).
文摘Photosynthesis,which provides oxygen and energy for all living organisms,is circadian regulated.Photosynthesis-associated metabolism must tightly coordinate with the circadian clock to maximize the efficiency of the light-energy capture and carbon fixation.However,the molecular basis for the interplay of photosynthesis and the circadian clock is not fully understood,particularly in crop plants.Here,we report two central oscillator genes of circadian clock,OsPRR95 and OsPRR59 in rice,which function as transcriptional repressors to negatively regulate the rhythmic expression of OsMGT3 encoding a chloroplast-localized Mg2+transporter.OsMGT3-dependent rhythmic Mg fluctuations modulate carbon fixation and consequent sugar output in rice chloroplasts.Furthermore,sugar triggers the increase of superoxide,which may act as a feedback signal to positively regulate the expression of OsPRR95 and OsPRR59.Taken together,our results reveal a negative-feedback loop that strengthens the crosstalk between photosynthetic carbon fixation and the circadian clock,which may improve plan adaptation and performance in fluctuating environments.
