On May 18th, Prof. Peng Shaobing’s rice research team published a paper titled “Leaf hydraulic vulnerability triggers the decline in stomatal and mesophyll conductance during drought in rice (Oryza sativa)” online on Journal of Experimental Botany. This study revealed that the reduction of leaf hydraulic conductance led to the rapid response of rice photosynthesis to drought stress.
Drought severely affects the plant growth and crop production. Stomatal closure during soil drought is the first physiological responses of crops to drought, which have been widely studied. The mechanism of stomatal closure is explained by two hypotheses——the hormonal hypothesis and the leaf turgor hypothesis, which are based on the data on atmospheric drought——the leaf-to-air vapor pressure deficit (VPD). Using rice as their research material, the rice research group of HZAU estimated the changes in carbon assimilation, leaf hydraulic conductance (Kleaf), and leaf turgor in rice (Oryza sativa) in response to both short- and long-term soil drought. The result shows that light-saturated photosynthetic rate (A) declined dramatically during the early stage of soil drought, mainly due to the decrease in stomatal conductance (gs) and mesophyll conductance (gm). The function of rubisco and electron transport chain is inhibited under severe drought stress conditions. The decrease of gs and gm is first triggered by the decline in Kleaf and abscisic acid (ABA)accumulation is associated with the decline in gs and gm. The results of this study provide insight into the regulation of carbon assimilation under drought conditions and guidance for the improvement of crop stress resistance.

Wang Xiaoxiao and Du Tingting, postgraduate students of 2017, are the first authors, and Dr. Xiong Dongliang is the corresponding author. The research is supported by the National Natural Science Foundation of China(NSFC) and the Program for Changjiang Scholars and Innovative Research Team (PCSIRT) of the Ministry of Education.

http://news.hzau.edu.cn/2018/0522/51987.shtml
Translator: Qi Yuhong
Proofreader: Wang Xiaoyan