J Plant Ecol ›› 2020, Vol. 13 ›› Issue (5): 563-573.DOI: 10.1093/jpe/rtaa043

• Research Articles • Previous Articles     Next Articles

Species-specific responses to drought, salinity and their interactions in Populus euphratica and P. pruinosa seedlings

Lei Yu1, Haojie Dong1, Zhijun Li2, Zhanjiang Han2, Helena Korpelainen3 and Chunyang Li1,*   

  1. 1Department of Ecology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China, 2Key Laboratory of Protection and Utilization of Biological Resources in Tarim Basin of Xinjiang, College of Life Sciences, Tarim University, Alar 843300, China, 3Department of Agricultural Sciences, Viikki Plant Science Centre, PO Box 27, FI-00014 University of Helsinki, Finland

    *Corresponding author. E-mail: licy@hznu.edu.cn
  • Received:2020-04-19 Revised:2020-06-19 Accepted:2020-07-10 Online:2020-07-17 Published:2020-10-01

Abstract:

Aims

Drought and salinity are severe abiotic stress factors, which limit plant growth and productivity, particularly in desert regions. In this study, we employed two desert poplars, Populus euphratica Oliver and Populus pruinosa Schrenk seedlings, to compare their tolerance to drought, salinity and combined stress.

Methods

We investigated species-specific responses of P. euphratica and P. pruinosa in growth, photosynthetic capacity and pigment contents, nonstructural carbohydrate concentrations, Cl allocation, osmotic regulation and the accumulation of reactive oxygen species (ROS) under drought, salinity and the combined stress.

Important Findings

Populus pruinosa exhibited greater growth inhibitory effects, photosynthesis decline, stomatal closure and ROS accumulation, and lower antioxidant enzyme activities and osmotic regulation compared with P. euphratica under drought, salinity and especially under their combined stress. On the other hand, salt-stressed P. euphratica plants restricted salt transportation from roots to leaves, and allocated more Cl to coarse roots and less to leaves, whereas salt-stressed P. pruinosa allocated more Cl to leaves. It was shown that there is species-specific variation in these two desert poplars, and P. pruinosa suffers greater negative effects compared with P. euphratica under drought, salinity and especially under the combined stress. Therefore, in ecological restoration and afforestation efforts, species-specific responses and tolerances of these two poplar species to drought and salinity should be considered under climate change with increasing drought and soil salinity developing.

Key words: desert poplars, drought and salinity, Cl? allocation and transportation, coarse and fine roots, tolerance

摘要:

干旱和盐胁迫是严重的非生物胁迫因子,限制植物的生长和生产力,特别是在沙漠地区。本研究采用两种沙漠杨树—胡杨(Populus euphratica)和灰杨(P. pruinosa)幼苗,比较它们对干旱、盐胁迫和两者交互胁迫的耐受性。研究了在干旱、盐胁迫和交互胁迫下,胡杨和灰杨在生长、光合能力和色素含量、非结构性碳水化合物浓度、Cl分配、渗透调节和活性氧积累等方面的物种特异性响应。研究结果表明, 与胡杨相比,灰杨在干旱、盐胁迫,特别是交互胁迫下表现出更高的生长抑制作用,光合作用下降,气孔关闭和活性氧积累,抗氧化酶活性和渗透调节能力下降。此外,在盐胁迫下,胡杨限制了盐从根部向叶片的转运,并且向粗根分配的Cl较多,向叶片分配的Cl较少,而灰杨向叶片分配较多的Cl。表明这两种杨树存在着物种特异性变化,在干旱、盐胁迫,特别是交互胁迫下,灰杨受到更大的负面作用。因此,在未来干旱和盐胁迫加重的气候环境下,在生态恢复和植树造林时,应考虑这两种杨树对干旱和盐胁迫的物种特异性响应和耐受性。

关键词: 沙漠杨树, 干旱和盐胁迫, Cl?分配和运输, 粗根和细根, 耐受性