Yan Weiming, Zhong Yangquanwei, Shangguan Zhouping
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China.
Sci Rep. 2016 Feb 12;6:20917. doi: 10.1038/srep20917.
Drought is considered to be one of the most devastating natural hazards, and it is predicted to become increasingly frequent and severe in the future. Understanding the plant gas exchange and water status response to drought is very important with regard to future climate change. We conducted a meta-analysis based on studies of plants worldwide and aimed to determine the changes in gas exchange and water status under different drought intensities (mild, moderate and severe), different photosynthetic pathways (C3 and C4) and growth forms (herbs, shrubs, trees and lianas). Our results were as follows: 1) drought negatively impacted gas exchange and water status, and stomatal conductance (gs) decreased more than other physiological traits and declined to the greatest extent in shrubs and C3 plants. Furthermore, C4 plants had an advantage compared to C3 plants under the same drought conditions. 2) The decrease in gs mainly reduced the transpiration rate (Tr), and gs could explain 55% of the decrease in the photosynthesis (A) and 74% of the decline in Tr. 3). Finally, gas exchange showed a close relationship with the leaf water status. Our study provides comprehensive information about the changes in plant gas exchange and water status under drought.
干旱被认为是最具破坏性的自然灾害之一，预计未来其发生频率将越来越高，程度也将越来越严重。就未来气候变化而言，了解植物气体交换和水分状况对干旱的响应非常重要。我们基于对全球植物的研究进行了一项荟萃分析，旨在确定不同干旱强度（轻度、中度和重度）、不同光合途径（C3和C4）以及生长形式（草本植物、灌木、乔木和藤本植物）下气体交换和水分状况的变化。我们的结果如下：1）干旱对气体交换和水分状况产生负面影响，气孔导度（gs）的下降幅度大于其他生理性状，在灌木和C3植物中下降幅度最大。此外，在相同干旱条件下，C4植物比C3植物具有优势。2）gs的下降主要降低了蒸腾速率（Tr），gs可以解释光合作用（A）下降的55%和Tr下降的74%。3）最后，气体交换与叶片水分状况密切相关。我们的研究提供了关于干旱条件下植物气体交换和水分状况变化的全面信息。
