Biology, abiotic factors and biotechnology influencing flower colour

Flower colour is an important feature that adds aesthetic value to flowering plants as a key element in consumer choice. Colour expression is determined by a combination of several factors: type, quantity and stability of pigments, pH of the cells, copigmentation, and translocation of the pigments themselves from the production site. Various factors, such as light, temperature, sugars, fertilisers and metals, can also influence its expressions. The pigments most responsible for the colour of flowers are flavonoids and carotenoids. Intervening on this character through technical-agronomic interventions, or by modifying the pigment composition in plants through traditional breeding or, more recently, acting on the biosynthetic pathway through genetic engineering, is a highly relevant goal. The technical, genetic and biochemical knowledge presented in this review provides the basis for increasing the chances of success.