Drought is a major limitation to the growth and productivity of trees and is expected to become increasingly important in many regions because of the ongoing climate change. To better understand the different protective mechanisms between male and female poplars to drought, a systemic physiological analysis was performed in Professor Chunyang Li's lab, Chengdu Institute of Biology, Chinese Academy of Sciences.

Treatments with three water regimes (controls, middle drought and severe drought) were applied to male and female Populus cathayana Rehd. for 2 months. It showed that drought-stressed males suffered less negative effects, higher photosynthetic rate and higher antioxidant enzyme activities than drought-stressed females.

These results indicated that males had more substances needed for osmotic adjustment, a better self-protection of the photosynthetic system and a more efficient enzymatic detoxification cycle in eliminating the negative effects caused by ROS than did females. Therefore, males possess a more efficient drought-induced protective mechanism than do females and the better protective mechanism in photosynthetic organelle is related to the higher photosynthetic activity in drought-stressed males.

This study entitled “Populus cathayana males exhibit more efficient protective mechanisms than females under drought stress” has been published in Forest Ecology and Management (2012, 275: 68–78).