Why sunburn does not affect plants

New York: Ever wondered how plants protect themselves from the harmful rays of the sun? Researchers have now discovered how they put natural sunscreens to use.

Plants produce special molecules and send them to the outer layer of their leaves to protect themselves, the findings showed.

These molecules, called sinapate esters, block ultraviolet-B radiation from penetrating deeper into the leaves where it might otherwise disrupt a plant's normal development.

"The harsh ultraviolet radiation plants are exposed to daily can cause serious damage to plant DNA and, as a result, hinder plant growth," said Timothy Zwier from Purdue University in the US.

Although researchers have been amassing evidence that points to sinapate esters as the protective molecules, no one had investigated in detail what happens to them under UV exposure. Zwier's team wanted to understand this process.

The researchers coaxed these molecules into the gas phase and zapped them with UV-B radiation from a laser in the laboratory.

They found that the particular sinapate ester that plants use as a screen against UV-B was inherently capable of soaking up radiation at every wavelength across the UV-B spectrum.

Thus, it is remarkably efficient at absorbing harsh radiation that could otherwise damage the plant.