Molecular genetic control of leaf lifespan in plants - A review

Leaf senescence constitutes the last stage of leaf development in plants and proceeds through a highlyregulated program in order to redistribution of micro- and macro-nutrients from the senescing leaves tothe developing/growing plant organs. Initiation and progression of leaf senescence is accompanied bymassive sequential alterations at various levels of leaf biology including leaf morphology and physiology,cell metabolism and structure, and gene transcription. In this regard, comprehensive expression analysisof senescence-associated genes (SAGs) and the identification of leaf senescence related mutants hasrevealed that leaf senescence is a complex genetically controlled program. In this review, we presentimportant findings about the molecular genetic mechanisms underlying leaf senescence in various plantswith a main focus on the model plant Arabidopsis thaliana. Functional analysis of leaf senescencemutants has provided new insights into the key processes that regulate the onset and progression of leafsenescence, thus allowing categorization of the various regulatory factors into several signallingpathways.

Keywords:

Leaf senescence , longevity , Arabidopsis