Exploring different environmental impacts: How abiotic factors shape flavonoid synthesis in plants

Abstract

Flavonoids are important class of secondary plant metabolites naturally distributed in flowers, fruits, seeds, and various plant parts. For plants, few colorful flavonoids (mainly anthocyanins) are of immense importance as a colorful pigment that acts as pollinator attractants while others are colorless and serve different biological functions. Moreover, it also plays important role in plant growth and development by acts as UV light protectants; as growth regulators; for cell signaling; to protect against environmental stresses and as defense molecules. Thus, flavonoids act as stress relievers and coping compounds for plants. The key stimulus for the biosynthesis of flavonoids is often abiotic stress. A plethora of evidence shows that flavonoid biosynthesis is influenced by abiotic stresses such as flooding, drought, soil salinity, low/high light intensity, metal stress, high temperature, nutrient scarcity etc. and makes a significant contribution to the response mechanisms of different medicinal herbal plants. Thus, appropriate abiotic factors can play a critical role in enhancing biosynthesis of medicinally and commercially important flavonoids. These factors can be incorporated during cultivation of flavonoid containing medicinal herbal plants for enhancing flavonoid biosynthesis as its accumulation behaviour varies depending on the developmental stage, species and even cultivars of the same species. This review not only highlights that molecular structure, classification and biosynthesis of flavonoid but also summarizes the impact on quality, quantity, and variety of flavonoids in plants as an adaptive response to cope up with unfavorable ecological conditions is also included.