Regulatory Cross-Talk between the Metabolic Pathways Responsible for Pigment Production in Plants

Carotenoids and flavonoids are the major class of pigments and impart varied colors to various plant tissues. The study of regulation of these pathways is important in order to understand the mechanisms underlying the stress alleviating properties of these compounds. Regulation of these pathways is aimed at controlling the amount and types of pigments produced and the physiological conditions (like temperature, pH) at which these are finally stored. Various factors (developmental factors, light induced signaling, circadian clock and hormonal response factors) show indirect effect on the composition and amount of carotenoids. In flavonoid pathway, the regulation via different factors influences anthocyanin accumulation by regulating the amount of carbon supply in the biosynthetic pathway. The transcription factors also play important role in regulation of both pathways. The present review aims at highlighting the regulation of two major pigment producing pathways via environmental and physiological factors.