Cao Xu, Jia Jingbo, Zhang Chao, Li Hong, Liu Tongxian, Jiang Xiangning, Polle Andrea, Peng Changhui, Luo Zhi-Bin
College of Life Sciences and State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China; Büsgen-Institute, Department of Forest Botany and Tree Physiology, Georg-August University, 37077, Göttingen, Germany.
Physiol Plant. 2014 Aug;151(4):480-94. doi: 10.1111/ppl.12138. Epub 2014 Jan 23.
Populus × euramericana (Pe) displays higher stable carbon isotope composition (δ(13)C) and intrinsic water use efficiency (WUEi) than Populus cathayana (Pc) under unlimited water conditions, rendering us to hypothesize that Pe is better acclimated to water deficiency than Pc. To examine this hypothesis, saplings of Pc and Pe were exposed to drought and subsequently re-watered. Pc and Pe exhibited distinct anatomical, physiological and transcriptional responses in acclimation to drought and re-watering, mainly due to stronger responsiveness of transcriptional regulation of genes encoding plasma membrane intrinsic proteins (PIPs), higher starch accumulation, δ(13)C, stable nitrogen isotope composition (δ(15)N) and WUEi , and lower reactive oxygen species (ROS) accumulation and scavenging in Pe. In acclimation to drought, both poplar genotypes demonstrated altered anatomical properties, declined height growth, differential expression of PIPs, activation of ABA signaling pathway, decreased total soluble sugars and starch, increased δ(13)C, δ(15)N and WUEi , and shifted homeostasis of ROS production and scavenging, and these changes can be recovered upon re-watering. These data indicate that Pe is more tolerant to drought than Pc, and that anatomical, physiological and transcriptional acclimation to drought and re-watering is essential for poplars to survive and grow under projected dry climate scenarios in the future.
在水分充足的条件下，欧美杨（Pe）比青杨（Pc）表现出更高的稳定碳同位素组成（δ(13)C）和内在水分利用效率（WUEi），这使我们推测Pe比Pc更能适应缺水环境。为验证这一假设，将Pc和Pe的树苗进行干旱处理，随后再浇水。Pc和Pe在适应干旱及再浇水过程中表现出不同的解剖学、生理学和转录反应，主要原因是Pe中编码质膜内在蛋白（PIPs）的基因转录调控反应更强、淀粉积累更多、δ(13)C、稳定氮同位素组成（δ(15)N）和WUEi更高，以及活性氧（ROS）积累和清除能力更低。在适应干旱过程中，两种杨树基因型均表现出解剖学特性改变、树高生长下降、PIPs差异表达、ABA信号通路激活、总可溶性糖和淀粉减少、δ(13)C、δ(15)N和WUEi增加，以及ROS产生和清除的稳态变化，且这些变化在再浇水后可恢复。这些数据表明，Pe比Pc更耐旱，并且对干旱和再浇水的解剖学、生理学和转录适应性对于杨树在未来预计的干旱气候情景下生存和生长至关重要。
