The molecular regulators, pathways, and environmental impacts of white flowers

Authors: SAGHEER AHMAD, ZAIBUN NISA, MUHAMMAD ZEESHAN MUNIR, MUHAMMAD IMRAN, SHAISTA NOSHEEN, KAI ZHAO

Abstract: White flowers are an important element of natural beauty, although they are thought of colorless. Anthocyanins are the major compounds responsible for a variety of pigments in flowers. White flowers surely lack pigmented anthocyanins and other compounds, but there are regulatory mechanisms that hinder the deposition of color pigments in white flowers. Moreover, there are also some compounds that deposit to instigate white appearance and the genetic regulators control the biosynthesis and deposition of such compounds. Experts have shown that fluctuation in the equilibrium of FLS and DFR genes determines the degree of accumulation of anthocyanins and flavonols in the flowers, leading to different color patterns. The gene suppression techniques to suppress certain flavonoid pathway genes, such as CHS, or the insertion of DNA transposable elements into CHS produce white flower color in a number of species. Although pigments find wide application in the everyday life, white color does possess special importance in nature. Land plants use white flowers for reproductive viability during cold early spring to conserve energy and reduce nutrient costs, particularly in low density pollinations. Moreover, white fruit skins deposit specific amounts of anthocyanins and phenols with significant health benefits. This review, thus, deciphers the regulatory mechanisms for the absence of pigments in the white flowers and the deposition of special compounds causing white appearance and the benefits of white color in nature.

Keywords: Anthocyanins, eco-environment, volatiles, white color, reproduction

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