Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 th...Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 that is responsible for the seed state transition from dormancy to germination.We show that dormancy-breaking factors activate the MKK3–MPK7 module,which affects the expression of some a-EXPANSIN(EXPA)genes to control seed dormancy.Furthermore,we identify a direct downstream substrate of this module,ERF4,which suppresses the expression of these EXPAs by directly binding to the GCC boxes in their exon regions.The activated MKK3–MPK7 module phosphorylates ERF4,leading to its rapid degradation and thereby releasing its inhibitory effect on the expression of these EXPAs.Collectively,our work identifies a signaling chain consisting of protein phosphorylation,degradation,and gene transcription,by which the germination promoters within the embryo sense and are activated by germination signals from ambient conditions.展开更多
基金supported by the National Natural Science Foundation of China(grant nos.32000250 and 32170364)the China Postdoctoral Science Foundation(grant no.2020M682997)+2 种基金the Key Area Research and Development Program of Guangdong Province(grant no.2021B0707010006)the Science,Technology and Innovation Commission of Shenzhen Municipality(grant nos.KCXFZ-20201221173203009 and KCXFZ20211020164207012)the Dapeng New District Science and Technology Program(grant nos.KJYF202101-09 and RCTD20180102)。
文摘Seeds establish dormancy to delay germination until the arrival of a favorable growing season.In this study,we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 that is responsible for the seed state transition from dormancy to germination.We show that dormancy-breaking factors activate the MKK3–MPK7 module,which affects the expression of some a-EXPANSIN(EXPA)genes to control seed dormancy.Furthermore,we identify a direct downstream substrate of this module,ERF4,which suppresses the expression of these EXPAs by directly binding to the GCC boxes in their exon regions.The activated MKK3–MPK7 module phosphorylates ERF4,leading to its rapid degradation and thereby releasing its inhibitory effect on the expression of these EXPAs.Collectively,our work identifies a signaling chain consisting of protein phosphorylation,degradation,and gene transcription,by which the germination promoters within the embryo sense and are activated by germination signals from ambient conditions.
