Time of day matters to thirsty trees

TORONTO, Nov. 25 (UPI) -- Canadian scientists say they've found the manner in which a forest's trees genetically cope with drought differs according to the time of day.

A University of Toronto research team led by Professor Malcolm Campbell examined how poplar trees use their 45,000 genes to respond to drought.

Campbell and doctoral student Olivia Wilkins said the use of different combinations of genes creates different programs. The genetic combination that trees use in response to a stress, such as drought, determines whether the tree can survive.

In the past, researchers examined drought-responsive gene programs at a single point in time -- normally during the day. But Wilkins said she conducted her genetic experiments at multiple times throughout the day and night.

She said she discovered trees use different drought response programs at different times of day.

"Previously, researchers referred to the drought response as though it was a single, simple program that ran all the time," Campbell said, noting the new research shows the story isn't that simple.

The scientists said their discovery that trees use different programs at different times of the day is a critical finding, since previous studies might have overemphasized the importance of some genes in helping trees contend with drought, and totally missed others that are important.

The research is reported in the Nov. 13 issue of the Plant Journal.