Question

What could have happened if plants blocked Anthocyanin?

Answer 1

Hint: Anthocyanins are water-soluble flavonoids. They are mostly purple and blue pigments that are found in fruit and flowers of many plants. They are formed by phenylpropanoid metabolism caused due to the presence of phenylalanine. They have antioxidant effects. They help in reproduction, pollination and seed dispersal. They have potential pharmaceutical uses when extracted from plants and provide us with a lot of health benefits.

Complete answer:
Anthocyanins help to fight abiotic as well as biotic stress as for example drought, UV-B, and heavy metals, etc. It provides resistance to pathogens and insects by:
Tomato fruits enriched with anthocyanins show lower susceptibility to gray mold and thus prevent pathogenic manifestation.
Wounded leaf tissues show faster recovery from oxidative stress caused by mechanical injury if they are anthocyanin-rich.
It absorbs high-energy quanta. The cell vacuoles both protect chloroplasts from the photo inhibitory effects as well as the photooxidative effects which are consequences of strong light. It prevents the catabolism of photolabile defence compounds. Anthocyanins reduce photooxidative injury in leaves efficiently. It is a useless by-product of the flavonoid pathway, but is critical for plant survival.
They are glycosylated polyphenolic compounds. Their color is influenced by the intravacuolar environment. They are derived from anthocyanidins, such as pelargonidin, cyanidin, delphinidin, peonidin, petunidin, and malvidin. Its content depends on the balance between two factors:
1. Biosynthesis
2. Degradation
Without these, parts of plants will be colorless. Seed dispersal and pollination will be affected. They protect fruits from photobleaching under light stress by accumulating in the young vegetative tissues and sun-exposed side of fruits. But photosynthesis is not hampered.

Note:
The anthocyanin cell vacuoles can prevent degradation of important photolabile molecules by using green light. It is done by using high energy quanta. They reduce both the frequency and severity of photoinhibition. This has been seen in many plant species. It has also helped in the expedition of photosynthetic recovery. The leaves are protected from the stress of photo inhibitory light fluxes. It is done by absorbing the excess photons (generally intercepted by chlorophyll b).