Grain chalkiness,an undesirable trait caused by complex factors,has great negative impacts on the quality and economic value of rice.However,little is known about the regulatory mechanism of grain chalkiness,particula...Grain chalkiness,an undesirable trait caused by complex factors,has great negative impacts on the quality and economic value of rice.However,little is known about the regulatory mechanism of grain chalkiness,particularly the effect of endoplasmic reticulum(ER)stress.Here,a genome-wide association study(GWAS)reveals that the transcription factor Osb ZIP60 is a vital regulator of rice grain chalkiness.Genetic analysis demonstrates that knockout of Osb ZIP60 results in extremely high grain chalkiness and aberrant structure of storage substances.Notably,the expression of unfolded protein response(UPR)genes,such as OsbZIP50,Os Bi P1,Os Bi P2 and Os Bi P3,is up-regulated in the endosperm cells of osbzip60,and overexpression of all these UPR genes causes various degrees of chalkiness.Furthermore,Osb ZIP60 is found to activate the expression of key genes related to grain chalkiness,such as GPA3,FSE1,FLO7,Chalk5,Os NF-YB1,and Os PK2,whose expression is significantly suppressed in osbzip60 and overexpression lines of Osb ZIP50,Os Bi P1,Os Bi P2,and Os Bi P3.Our study provides novel insights into the function of Osb ZIP60 and the role of the UPR pathway in the formation of grain chalkiness in rice.展开更多
基金supported by grants from the National Key Research and Development Program of China (2021YFF1000202)the National Natural Science Foundation of China (31771368, 31821005,31701397)+3 种基金Ten-thousand Talents Programs of ChinaFundamental Research Funds for the Central Universities (2662020SKPY006)Wuhan Applied Foundational Frontier Project (2020020601012257)Hubei Hongshan Laboratory (2021hszd005),China
文摘Grain chalkiness,an undesirable trait caused by complex factors,has great negative impacts on the quality and economic value of rice.However,little is known about the regulatory mechanism of grain chalkiness,particularly the effect of endoplasmic reticulum(ER)stress.Here,a genome-wide association study(GWAS)reveals that the transcription factor Osb ZIP60 is a vital regulator of rice grain chalkiness.Genetic analysis demonstrates that knockout of Osb ZIP60 results in extremely high grain chalkiness and aberrant structure of storage substances.Notably,the expression of unfolded protein response(UPR)genes,such as OsbZIP50,Os Bi P1,Os Bi P2 and Os Bi P3,is up-regulated in the endosperm cells of osbzip60,and overexpression of all these UPR genes causes various degrees of chalkiness.Furthermore,Osb ZIP60 is found to activate the expression of key genes related to grain chalkiness,such as GPA3,FSE1,FLO7,Chalk5,Os NF-YB1,and Os PK2,whose expression is significantly suppressed in osbzip60 and overexpression lines of Osb ZIP50,Os Bi P1,Os Bi P2,and Os Bi P3.Our study provides novel insights into the function of Osb ZIP60 and the role of the UPR pathway in the formation of grain chalkiness in rice.
