脱落酸在低氮条件下延缓拟南芥叶片衰老

摘要

The effect of abscisic acid (ABA)on leaf senescence of Arabidopsis thaliana on culture media added with different nitrogen contents and sugar sources was investigated through determining the leaves' maximum photosynthetic efficiency (Fv∕Fm)and chlorophyll content.The results showed that the leaves' Fv∕Fm and chlorophyll contents of A.thaliana growing on the low-nitrogen medium added with sucrose were significantly less than those on the other media,meaning that adding sucrose to the low-nitrogen medium accelerated A. thaliana leaf senescence. The leaves' Fv∕Fm of A. thaliana growing on the low-nitrogen medium added with sucrose rose as the exogenous ABA content increased,but that on the low-nitrogen medium added with glucose decreased as the exogenous ABA content increased,indicating that ABA delayed the leaf senescence of A. thaliana growing on the low-nitrogen medium with sucrose. The above results were verified by testing for the expression of the senescence-associated gene SAG12 of A.thaliana.%通过测定PSII原初光能转化效率(Fv∕Fm)和叶绿素含量,研究外源脱落酸(ABA)对在培养基中添加不同氮含量及不同糖源条件下生长的拟南芥叶片衰老的影响.结果表明:在添加蔗糖的低氮含量培养基上生长的拟南芥叶片的Fv∕Fm和叶绿素含量明显低于其他培养基上生长的拟南芥,说明在低氮培养基中添加蔗糖加速拟南芥叶片衰老.在添加蔗糖的低氮培养基上生长的拟南芥叶片的Fv∕Fm值随着外源ABA含量的增加而上升;相反,在添加葡萄糖的低氮含量培养基上生长的拟南芥叶片的Fv∕Fm值随着外源ABA含量的增加而降低,表明ABA延缓在低氮含量和蔗糖培养基生长的拟南芥叶片衰老.通过衰老相关基因(SAG12)表达量的检测,验证了上述结果.