INHIBITION OF LEAF SENESCENCE BY AUTOREGULATED PRODUCTION OF CYTOKININ
INHIBITION OF LEAF SENESCENCE BY AUTOREGULATED PRODUCTION OF CYTOKININ
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DOI：
10.1126/science.270.5244.1986
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发表时间：
1995-12-22
期刊：
影响因子：
56.9
通讯作者：
AMASINO, RM
中科院分区：
文献类型：
--
作者：
GAN, SS;AMASINO, RM
用衰老特异性启动子控制IPT（编码异戊烯基转移酶（催化细胞分裂素生物合成中的限速步骤的酶）的基因）的表达导致叶片衰老的抑制。表达该嵌合基因的转基因烟草植物不表现出通常与IPT表达相关的发育异常，因为该系统是自动调节的。因为产生足够的细胞分裂素来延缓衰老，所以衰老特异性启动子的活性减弱。延缓衰老的叶子表现出延长的光合作用活跃的寿命。这一结果表明，内源性产生的细胞分裂素可以调节衰老，并提供了一个系统，专门操纵衰老程序。
Controlling expression of IPT, a gene encoding isopentenyl transferase (the enzyme that catalyzes the rate-limiting step in cytokinin biosynthesis), with a senescence-specific promoter results in the suppression of leaf senescence. Transgenic tobacco plants expressing this chimeric gene do not exhibit the developmental abnormalities usually associated with IPT expression because the system is autoregulatory. Because sufficient cytokinin is produced to retard senescence, the activity of the senescence-specific promoter is attenuated. Senescence-retarded leaves exhibit a prolonged, photosynthetically active life-span. This result demonstrates that endogenously produced cytokinin can regulate senescence and provides a system to specifically manipulate the senescence program.