Water soluble yellow pigment present in the petals of Tagetes and sunflower is anthoclor.

Anthoclor:
Anthoclor is a water-soluble yellow pigment that belongs to the class of flavonoids. It is responsible for the yellow coloration of the petals in Tagetes (marigold) and sunflower. Anthoclor is also found in other plants and is responsible for the yellow, orange, and red coloration in flowers, fruits, and leaves.

Function:
The function of anthoclor in plants is multifaceted. It plays a role in attracting pollinators, such as bees and butterflies, by providing visual cues. The bright yellow color serves as a signal to potential pollinators, indicating the presence of nectar or pollen-rich rewards. This helps in the process of pollination, ensuring the reproduction and survival of these plant species.

Biosynthesis:
Anthoclor biosynthesis occurs through the phenylpropanoid pathway. It starts with the conversion of phenylalanine to cinnamic acid by the enzyme phenylalanine ammonia-lyase (PAL). Subsequently, cinnamic acid is converted to p-coumaric acid, followed by the formation of chalcone. Chalcone is then converted to dihydrochalcone, which serves as a precursor for the synthesis of various flavonoids, including anthoclor.

Factors affecting anthoclor production:
Several factors can influence the production of anthoclor in plants. These include genetic factors, environmental conditions (such as light intensity, temperature, and nutrient availability), and hormonal regulation. Different plant species may produce different types and amounts of anthoclor depending on these factors.

Importance:
Anthoclor has significant ecological and economic importance. It contributes to the aesthetic appeal of flowers and fruits, making them visually attractive to both humans and pollinators. Additionally, anthoclor-rich plants have been traditionally used in herbal medicine for their potential health benefits. Some studies suggest that anthoclor possesses antioxidant and anti-inflammatory properties, which may contribute to human health and well-being.

In conclusion, anthoclor is the water-soluble yellow pigment present in the petals of Tagetes and sunflower. It serves multiple functions in plants, including attracting pollinators and providing potential health benefits. The biosynthesis of anthoclor occurs through the phenylpropanoid pathway, and its production can be influenced by various factors.

Choromoplasts also occur in petals but colours of petals are mainly due to water soluble pigments which occur in cell sap e.g. Anthocyanin-Blue, violet or red pigment; Anthoclor-Yellow pigment.