The genes behind anthocyanins have been discovered

Oct 3, 2007 09:41 GMT  ·  By

Plants can be compared to nice human bodies: their colors reflect the plant's health. A plant's main pigments are of two types: caretonoids, the 'precursors' of the vitamin A that give yellow-orange-red hues and anthocyanins that create blue-red hues. A new research has made a crucial advance in explaining the genetic processes that confer flowers and leaves magnificent colors, a knowledge that can have applications in improving the cancer-fighting traits of plant pigments and novel, healthier food colorings.

The team at the John Innes Center and Institute of Food Research in Norwich has detected an essential group of enzymes connected to the synthesis of the anthocyanins. Anthocyanins are found both in blue to red flowers, attracting pollinators, or blue to red fruits (like plums or apples), luring foraging animals. Some ornamental plant varieties have anthocyanins in their leaves, conferring them a color different from green (bluish or reddish).

These pigments also defend the plant against environmental stress and disease. There are hundreds of anthocyanin molecules in nature, all having slightly different chemical formulas. The research team detected the genes encoding the enzymes that chemically alter anthocyanins, changing their qualities.

"Using a new strategy, we conducted biochemical studies on the brassica (cabbage related) plant Arabidopsis. We found that a small number of genes responsible for the enzymes that chemically modify anthocyanins were 'switched on' when the plants were making anthocyanins in response to stress." said lead researcher Prof Cathie Martin at the John Innes Center.

"When we transferred these genes to a tobacco plant, the color of the tobacco flowers changed slightly, confirming that these genes, and the enzymes that they produce, were indeed responsible for modifying anthocyanins. What's more, these anthocyanins that had been modified by the enzymes were more stable than those that hadn't. This is significant because stabilized anthocyanins could be used as natural food colorants to replace many artificial colors used in various foods. This improved understanding of the genetics of anthocyanins also provides a better platform for studying their antioxidant properties, important in the fight against cancer, cardiovascular disease and age-related degeneration."