Abstract
Secondary vascular tissue(SVT)development and regeneration are regulated by phytohormones.In this study,we used an in vitro SVT regeneration system to demonstrate that gibberellin(GA)treatment sig-nificantly promotes auxin-induced cambium rees-tablishment.Altering GA content by overexpressing or knocking down ent-kaurene synthase(KS)af-fected secondary growth and SVT regeneration in poplar.The poplar DELLA gene GIBBERELLIC ACID INSENSITIVE(PtoGAI)is expressed in a specific pattern during secondary growth and cambium re-generation after girdling.Overexpression of PtoGAI disrupted poplar growth and inhibited cambium regeneration,and the inhibition of cambium re-generation could be partially restored by GA appli-cation.Further analysis of the PtaDR5:GUS trans-genic plants,the localization of PIN-FORMED 1(PIN1)and the expression of auxin-related genes found that an additional GA treatment could enhance the auxin response as well as the expression of PIN1,which mediates auxin transport during SVT re-generation.Taken together,these findings suggest that GA promotes cambium regeneration by stim-ulating auxin signal transduction.
基金项目
National Natural Science Foundation of China(32071726)
National Natural Science Foundation of China(32271825)
National Center for Protein Sciences at Peking University()
维普
万方数据