Heading date(or flowering time)is one of the most important agronomic traits in rice,influencing its regional adaptability and crop yield.Many major-effect genes for rice heading date have been identified,but in pract...Heading date(or flowering time)is one of the most important agronomic traits in rice,influencing its regional adaptability and crop yield.Many major-effect genes for rice heading date have been identified,but in practice they are difficult to be used for rice molecular breeding because of their dramatic effects on heading date.Genes with minor effects on heading date,which are more desirable for fine-tuning flowering time without significant yield penalty,were seldom reported.In this study,we identified a new minor-effect heading date repressor,Delayed Heading Date 4(DHD4).The dhd4 mutant shows a slightly earlier flowering phenotype without a notable yield penalty compared with wild-type plants under natural long-day conditions.DHD4 encodes a CONSTANS-like transcription factor localized in the nucleus.Molecular,biochemical,and genetic assays show that DHD4 can compete with 14-3-3 to interact with OsFD1,thus affecting the formation of the Hd3a-14-3-3-OsFD1 triprotein FAC complex,resulting in reduced expression of OsMADS14 and OsMADS15,and ultimately delaying flowering.Taken together,these results shed new light on the regulation of flowering time in rice and provide a promising target for fine-tuning flowering time to improve the regional adaptability of rice.展开更多
In a 2-year experiment, 187 genotypes were grown under well-watered and drought stress conditions, imposed at panicle initiation stage. The relationship of genotypic variation in yield under drought conditions to pote...In a 2-year experiment, 187 genotypes were grown under well-watered and drought stress conditions, imposed at panicle initiation stage. The relationship of genotypic variation in yield under drought conditions to potential yield, heading date and flowering delay, reduction in plant height, and to a drought response index (DRI) was detected. Grain yield under drought stress conditions was associated with yield under well-watered conditions (r= 0.47^**, and r= 0.61^** during 2 years of tests). The delay of heading date ranged from -1 (no delay) to 24days, and was negatively associated with grain yield (r =-0.40^*), spikelet fertility percentage (r =-0.40^**), harvest index (r =-0.58^**), but positively associated with yield reduction percentage (r = 0.60^**). The reduction in plant height was negatively associated with grain yield (r =-0.24^**, and r=-0.29^**), spikelet fertility percentage (r = -0.23^**, and r= -0.21^*), harvest index (r = -0.37^**, and r= -0.54^**), and positively associated with yield reduction percentage (r = 0.58^**, and r= 0.58^**) in 2003 and 2004, respectively. The DRI of genotypes was strongly associated with grain yield (r = 0.87^**, and r= 0.77^**), fertility percentage (r = 0.66^** and r= 0.54^**), harvest index (r= 0.67^** and r= 0.61^**), and negatively associated with grain reduction percentage (r=-0.70^**, and r=-0.73^**) under drought stress. The results indicate that genotypes with drought resistance can be identified by measuring yield potential, delay in flowering, reduction in plant height, or DRI under test environments of well-watered and drought stress.展开更多
基金This research was supported by grants from the Ministry of Agriculture of China for Transgenic Research,China(2016ZX08009-003)the Central Public-Interest Scientific Institution Basal Research Fund,China(Y2020YJ10)+2 种基金the National Natural Science Foundation of China,China(31771764,91935303,31871603,and U1701232)the National Key Research and Development Program of China,China(2016YFD0100403 and 2016YFD0100301)the CAAS Innovation Project,China(CAASZDXT2019003).
文摘Heading date(or flowering time)is one of the most important agronomic traits in rice,influencing its regional adaptability and crop yield.Many major-effect genes for rice heading date have been identified,but in practice they are difficult to be used for rice molecular breeding because of their dramatic effects on heading date.Genes with minor effects on heading date,which are more desirable for fine-tuning flowering time without significant yield penalty,were seldom reported.In this study,we identified a new minor-effect heading date repressor,Delayed Heading Date 4(DHD4).The dhd4 mutant shows a slightly earlier flowering phenotype without a notable yield penalty compared with wild-type plants under natural long-day conditions.DHD4 encodes a CONSTANS-like transcription factor localized in the nucleus.Molecular,biochemical,and genetic assays show that DHD4 can compete with 14-3-3 to interact with OsFD1,thus affecting the formation of the Hd3a-14-3-3-OsFD1 triprotein FAC complex,resulting in reduced expression of OsMADS14 and OsMADS15,and ultimately delaying flowering.Taken together,these results shed new light on the regulation of flowering time in rice and provide a promising target for fine-tuning flowering time to improve the regional adaptability of rice.
基金Jointly supported by grants from Chinese Ministry of Agriculture(948-2001-101)Shanghai Municipal Science and Technology Commission(2005DJ14008)Shanghai Municipal Agriculture Commission and the Rockefeller Foundation(2004FS071),New York,USA.
文摘In a 2-year experiment, 187 genotypes were grown under well-watered and drought stress conditions, imposed at panicle initiation stage. The relationship of genotypic variation in yield under drought conditions to potential yield, heading date and flowering delay, reduction in plant height, and to a drought response index (DRI) was detected. Grain yield under drought stress conditions was associated with yield under well-watered conditions (r= 0.47^**, and r= 0.61^** during 2 years of tests). The delay of heading date ranged from -1 (no delay) to 24days, and was negatively associated with grain yield (r =-0.40^*), spikelet fertility percentage (r =-0.40^**), harvest index (r =-0.58^**), but positively associated with yield reduction percentage (r = 0.60^**). The reduction in plant height was negatively associated with grain yield (r =-0.24^**, and r=-0.29^**), spikelet fertility percentage (r = -0.23^**, and r= -0.21^*), harvest index (r = -0.37^**, and r= -0.54^**), and positively associated with yield reduction percentage (r = 0.58^**, and r= 0.58^**) in 2003 and 2004, respectively. The DRI of genotypes was strongly associated with grain yield (r = 0.87^**, and r= 0.77^**), fertility percentage (r = 0.66^** and r= 0.54^**), harvest index (r= 0.67^** and r= 0.61^**), and negatively associated with grain reduction percentage (r=-0.70^**, and r=-0.73^**) under drought stress. The results indicate that genotypes with drought resistance can be identified by measuring yield potential, delay in flowering, reduction in plant height, or DRI under test environments of well-watered and drought stress.