As a representative form of plant senescence, leaf senescence has received the most attention during the last two decades. In this chapter we summarize the initiation of leaf senescence by various internal and external signals, the progression of senescence including switches in gene expression, as well as changes at the biochemical and cellular levels during leaf senescence. Impacts of leaf senescence in agriculture and genetic approaches that have been used in manipulating leaf senescence of crop plants are discussed.
Keywords: AtNAP; Chlorophyll; Hormones; IPT; Leaf senescence; Nutrient recycling; Protein degradation; Signals; Transcription factors.