细胞分裂素延缓叶片衰老的机制研究进展

Research progress on the mechanisms of cytokinin-inhibited leaf senescence

细胞分裂素(CK)是一类由N6-腺嘌呤衍生物组成的小分子植物激素,在植物生长发育、衰老、抗病、抗逆等生命活动中发挥重要作用。叶片衰老是叶片生命周期的最后一个阶段,在这一时期叶绿素含量下降,叶片开始黄化,活性氧积累,细胞中各种水解酶激活,最后细胞大量死亡。大量研究表明CK能够延缓叶片衰老,但其分子机制有待深入研究。本文概括了内外源CK调节叶片衰老的特点,对糖信号和激素互作在CK延缓叶片衰老过程中的作用机理分别进行了综述,并对CK调控叶片衰老的研究方向进行了讨论。

Cytokinins(CKs) are a kind of plant hormone composed of N6-adenine derivatives, which play important roles in plant growth and development, leaf senescence, disease resistance and stress responses. Leaf senescence is the final stage of its life cycle. During this process, chlorophyll contents decrease, reactive oxygen species increase, and various intracellular hydrolytic enzymes are activated, thereby resulting in cell death. Although plenty of studies have shown that CKs inhibit leaf senescence, the related molecular mechanisms remain to be further investigated. The inhibition of leaf senescence by endogenous and exogenous CKs, and the roles of sugar signals and hormone crosstalks in cytokinin-inhibited leaf senescence are summarized in this review. The future work of leaf senescence regulated by CKs was discussed.