Making sense of senescence - Molecular genetic regulation and manipulation of leaf senescence
Making sense of senescence - Molecular genetic regulation and manipulation of leaf senescence
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DOI：
10.1104/pp.113.2.313
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发表时间：
1997-02-01
期刊：
影响因子：
7.4
通讯作者：
Amasino, RM
中科院分区：
文献类型：
--
作者：
Gan, SS;Amasino, RM
叶片衰老是叶片发育的最后阶段。在落叶乔木林中，在树叶衰老过程中形成的秋色具有很大的审美价值。这一过程也具有很大的实用价值，因为在叶片衰老期间，养分被循环到植物的其他部位。例如，落叶树叶中的氮被用来合成茎中的储存蛋白质，以支持下一年春天的生长(Clausen和Apel，1991)。然而，在农业环境中，叶片衰老可能会限制某些作物的产量。衰老也是蔬菜作物采后损失的原因之一。因此，对叶片衰老的研究不仅有助于我们对这一基本发育过程的认识，而且还可能为农业应用提供控制衰老的方法。对叶片衰老有许多生理、生化和分子方面的研究。这些研究表明，在衰老过程中，叶片细胞在细胞结构、新陈代谢和基因表达方面经历了高度协调的变化。细胞结构中最早和最显著的变化是叶绿体的分解，叶绿体是含有高达70%的叶蛋白的细胞器。在新陈代谢方面，碳同化(光合作用)被叶绿素和大分子(如蛋白质、膜脂和RNA)的分解代谢所取代，因此一些释放的营养物质可以被循环利用。在分子水平上，这些变化伴随着基因表达的变化，或者可能是由基因表达的变化驱动的。本文综述了有关叶片衰老的生理生化研究进展，并讨论了S等植物叶片衰老调控机制的分子研究现状。
Leaf senescence is the final stage of leaf development. In forests of deciduous trees, the autumn colors that develop during leaf senescence are of great aesthetic value. This process is also of great practical value because during leaf senescence, nutrients are recycled to other parts of the plant. For example, nitrogen from leaves of deciduous trees is used for the synthesis of storage proteins in stems that will support growth during the following spring (Clausen and Apel, 1991). However, in an agricultural setting, leaf senescence may limit yield in certain crops. Senescence also contributes to the postharvest loss of vegetable crops. Therefore, studying leaf senescence will not only contribute to our knowledge about this fundamental developmental process, but may also lead to ways of manipulating senescence for agricultural applications. There have been many physiological, biochemical, and molecular studies of leaf senescence. These studies show that during senescence leaf cells undergo highly coordinated changes in cell structure, metabolism, and gene expression. The earliest and most significant change in cell structure is the breakdown of the chloroplast, the organelle that contains up to 70% of the leaf protein. Metabolically, carbon assimilation (photosynthesis) is replaced by catabolism of chlorophyll and macromolecules such as proteins, membrane lipids, and RNA so that some of the released nutrients can be recycled. At the molecular level, these changes are accompanied by, or perhaps driven by, changes in gene expression. In this Update, we summarize physiological and biochemical studies that have contributed to the present understanding of leaf senescence, then we discuss current molecular investigations into the regulatory mechanism (s) underlying leaf senescence, and, fi-