식물의 엽록소 생합성 및 조절 기작에 대한 주요 연구동향

Recent Advances in Genetic Regulation of Chlorophyll Metabolism in Plants

Chlorophyll is an essential pigment involved in light absorption and electron transfer in photosynthesis, a photochemical processthat is indispensable for plant growth and development. The biosynthesis of chlorophyll occurs in plastids and shares a common biosyntheticpathway with other tetrapyrroles. The chlorophyll metabolic pathway is divided into four distinct components: the common pathway,chlorophyll-specific biosynthetic pathway, chlorophyll cycle, and chlorophyll degradation pathway, which are regulated in developmental- andenvironmental-specific manners. During the early stages of plant growth, the expression of most chlorophyll biosynthetic genes is inducedby light, resulting in an increase in chlorophyll accumulation, induction of high photosynthetic activity, and continuous plant growth. In contrast,during plant maturation, the expression of most of these genes is gradually downregulated, whereas genes involved in chlorophyll degradationare upregulated during leaf senescence. Chlorophyll biosynthesis is directly or indirectly regulated by the members of various transcriptionfactor families. In this review, we describe representative mechanisms of transcription factor-mediated activation and repression of chlorophyllbiosynthesis in response to light treatment. We also present an overview of recent studies that have examined all the enzymatic steps involvedin chlorophyll metabolic pathways and their gene regulation at the transcriptional level, which will enable readers to gain a better understandingof chlorophyll metabolism.