In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating...In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process.However,the underlying molecular mechanismfor the establishment of auxin concentration is not fully understood.In this study,we identified two function-unknown MADS-box genes,VCM1 and VCM2,which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin.Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation.Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression,which tuned the soluble auxin concentration in the vascular cambium area.This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.展开更多
基金supported by the Ministry of Science and Technology of the People’s Republic of China(2016YFD0600104)the National Natural Science Foundation of China(31630014)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB27020104).
文摘In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process.However,the underlying molecular mechanismfor the establishment of auxin concentration is not fully understood.In this study,we identified two function-unknown MADS-box genes,VCM1 and VCM2,which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin.Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation.Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression,which tuned the soluble auxin concentration in the vascular cambium area.This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.
