Regulation of seed size is a key strategy for improving crop yield and is also a basic biological question.However,the molecular mechanisms by which plants determine their seed size remain elusive.Here,we report that ...Regulation of seed size is a key strategy for improving crop yield and is also a basic biological question.However,the molecular mechanisms by which plants determine their seed size remain elusive.Here,we report that the GW2-WG1-OsbZIP47 regulatory module controls grain width and weight in rice.WG1,which encodes a glutaredoxin protein,promotes grain growth by increasing cell proliferation.Interestingly,WG1 interacts with the transcription factor OsbZIP47 and represses its transcriptional activity by associating with the transcriptional co-repressor ASP1,indicating that WG1 may act as an adaptor protein to recruit the transcriptional co-repressor.In contrary,OsbZIP47 restricts grain growth by decreasing cell proliferation.Further studies reveal that the E3 ubiquitin ligase GW2 ubiquitinates WG1 and targets it for degradation.Genetic analyses confirm that GW2,WG1,and OsbZIP47 function in a comm on pathway to control grain growth.Taken together,ourfindi ngs reveal a genetic and molecular framework for the control of grain size and weight by the GW2-WG1-OsbZIP47 regulatory module,providing new targets for improving seed size and weight in crops.展开更多
In high-light environments, plants are exposed to different types of stresses, such as an excess of UV-B, but also drought stress which triggers a common morphogenic adaptive response resulting in a general reduction ...In high-light environments, plants are exposed to different types of stresses, such as an excess of UV-B, but also drought stress which triggers a common morphogenic adaptive response resulting in a general reduction of plant growth. Here, we report that the Arabidopsis thaliana UVRESISTANCE LOCUS 8 （UVR8） gene, a known regulator of the UV-B morphogenic response, was able to complement a Saccharomyces cerevisiae osmo-sensitive mutant and its expression was induced after osmotic or salt stress in Arabidopsis plants. Under low levels of UV-B, plants overexpressing UVR8 are dwarfed with a reduced root development and accumulate more flavonoids compared to control plants. The growth defects are mainly due to the inhibition of cell expansion. The growth inhibition triggered by UVR8 overexpression in plants under low levels of UV-B was exacerbated by mannitol-induced osmotic stress, but it was not significantly affected by ionic stress. In contrast, uvr8-6 mutant plants do not differ from wild-type plants under standard conditions, but they show an increased shoot growth under high-salt stress. Our data suggest that UVR8-mediated accumulation of flavonoid and possibly changes in auxin homeostasis are the underlying mechanism of the observed growth phenotypes and that UVR8 might have an important role for integrating plant growth and stress signals.展开更多
基金supported by grants from the National Natural Science Foundation of China(3181101602 to Y.L,91735302 to Y.L.,3187080209 to N.L.,91735304 to Q.Q.,31571742 to D.W.)the strategic priority research program of the Chinese Academy of Sciences(XDB27010102)+3 种基金the National Basic Researoh Program of China(2018YFD1000706-10 to R.X.,2016YFD0100501 to N.L.,2016YFD0100402 to P.D.,2016YFD0100401 to D.W.,2017YFD0101701 to R.X.)the National Ten-Thousand Talents Program of China to Y.LI.the Youth innovation promotion association CAS to P.D.(2019102)the National Special Project(2016ZX08009003-003).
文摘Regulation of seed size is a key strategy for improving crop yield and is also a basic biological question.However,the molecular mechanisms by which plants determine their seed size remain elusive.Here,we report that the GW2-WG1-OsbZIP47 regulatory module controls grain width and weight in rice.WG1,which encodes a glutaredoxin protein,promotes grain growth by increasing cell proliferation.Interestingly,WG1 interacts with the transcription factor OsbZIP47 and represses its transcriptional activity by associating with the transcriptional co-repressor ASP1,indicating that WG1 may act as an adaptor protein to recruit the transcriptional co-repressor.In contrary,OsbZIP47 restricts grain growth by decreasing cell proliferation.Further studies reveal that the E3 ubiquitin ligase GW2 ubiquitinates WG1 and targets it for degradation.Genetic analyses confirm that GW2,WG1,and OsbZIP47 function in a comm on pathway to control grain growth.Taken together,ourfindi ngs reveal a genetic and molecular framework for the control of grain size and weight by the GW2-WG1-OsbZIP47 regulatory module,providing new targets for improving seed size and weight in crops.
文摘In high-light environments, plants are exposed to different types of stresses, such as an excess of UV-B, but also drought stress which triggers a common morphogenic adaptive response resulting in a general reduction of plant growth. Here, we report that the Arabidopsis thaliana UVRESISTANCE LOCUS 8 （UVR8） gene, a known regulator of the UV-B morphogenic response, was able to complement a Saccharomyces cerevisiae osmo-sensitive mutant and its expression was induced after osmotic or salt stress in Arabidopsis plants. Under low levels of UV-B, plants overexpressing UVR8 are dwarfed with a reduced root development and accumulate more flavonoids compared to control plants. The growth defects are mainly due to the inhibition of cell expansion. The growth inhibition triggered by UVR8 overexpression in plants under low levels of UV-B was exacerbated by mannitol-induced osmotic stress, but it was not significantly affected by ionic stress. In contrast, uvr8-6 mutant plants do not differ from wild-type plants under standard conditions, but they show an increased shoot growth under high-salt stress. Our data suggest that UVR8-mediated accumulation of flavonoid and possibly changes in auxin homeostasis are the underlying mechanism of the observed growth phenotypes and that UVR8 might have an important role for integrating plant growth and stress signals.
