tailieunhanh - Leaf senescence - not just a ‘wear and tear’ phenomenon

A recent, genome-wide study shows that the transcriptional program underlying leaf senescence is active and complex, reflecting the activation of more than 2,000 genes in Arabidopsis, with gene products involved in a broad spectrum of regulatory, biochemical and cellular events. reports deposited research Aging and senescence in plants Senescence, aging and death - conceived of in the past as inevitable, negative processes - are now considered an integral part of differentiation and development. Leaf senescence is one of the most conspicuous. | Minireview Leaf senescence - not just a wear and tear phenomenon Shimon Gepstein Address Faculty of Biology Technion-Israel Institute of Technology Haifa 32000 Israel. E-mail gepstein@ Published 27 February 2004 Genome Biology 2004 5 212 The electronic version of this article is the complete one and can be found online at http 2004 5 3 2l2 2004 BioMed Central Ltd Abstract A recent genome-wide study shows that the transcriptional program underlying leaf senescence is active and complex reflecting the activation of more than 2 000 genes in Arabidopsis with gene products involved in a broad spectrum of regulatory biochemical and cellular events. Aging and senescence in plants Senescence aging and death - conceived of in the past as inevitable negative processes - are now considered an integral part of differentiation and development. Leaf senescence is one of the most conspicuous processes to have been studied in the context of plant aging and senescence and has an important impact on agriculture affecting crop yield and the shelf life of leafy vegetables 1 2 . This terminal phase of leaf development cannot be described simply as a collection of passive and deteriorative processes during which a gradual decline in vital systems takes place. Extensive physiological and biochemical studies on leaf senescence in the last three decades have suggested that it is a highly regulated and active process which is characterized by differential and sequential changes in almost every subcellular compartment. Leaf senescence involves diverse metabolic changes associated with multiple biochemical pathways 1-3 . Guo et al. 4 now report a comprehensive study on the transcriptional program of Arabidopsis leaf senescence. This study not only provides genetic confirmation for many previous biochemical and physiological findings but also adds significant new information indicating that leaf senescence like other developmental processes is a very dynamic