Physiological response of riparian plants to watering in hyper-arid areas of Tarim River, China
Physiological response of riparian plants to watering in hyper-arid areas of Tarim River, China
RUAN Xiao1, WANG Qiang1, CHEN Yaning2, LI Weihong2
1.Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China; 2.Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;
Abstract：The physiological responses and adaptive strategies of Populus euphratica Oliv. (arbor species), Tamarix ramosissima Ldb. (bush species), and Apocynum venetum L. (herb species) to variations in water and salinity stress were studied in the hyper-arid environment of the Tarim River in China. The groundwater table, the saline content of the groundwater, as well as the content of free proline, soluble sugars, plant endogenous hormones (abscisic acid (ABA), and cytokinins (CTK)) of the leaves of the three species were monitored and analyzed at the lower reaches of the Tarim River in the study area where five transects were fixed at 100 m intervals along a vertical sampling line before and after water release. Saline stress dramatically increased soluble sugar concentration of the three species. Differences in sugar accumulation were determined among the species at different transects. The free proline concentration of the leaves of T. ramosissima and P. euphratica showed a proportional decrease with various degrees of elevation of the groundwater table after water release. There was a least correlation between the soluble sugars and proline stimulation in T. ramosissima. It was strongly suggested that T. ramosissima developed a different strategy to accumulate organic solutes to adapt to the stress environment. The soluble sugars and proline accumulation responded to the changes of groundwater table independently: the former occurred under salt stress, whereas the latter was more significant under drought stress. The concentration and the increase in concentration of ABA and CTK involved in stress resistance of the three species were also determined. This increase in the hormone concentration in P. euphratica was different from that of the other two species. Expressed as a function of increase of ABA concentration in leaves, A. venetum and T. ramosissima showed a different solute accumulation in response to groundwater table. There was a significant correlation between ABA accumulation andΔ [proline] in A. venetum as well as between ABA accumulation and Δ [sugar] in T. ramosissima.
出版日期: 2007-03-05
引用本文:
. Physiological response of riparian plants to watering in hyper-arid areas of Tarim River, China[J]. Frontiers of Biology in china, 2007, 2(1): 54-61.
RUAN Xiao, WANG Qiang, CHEN Yaning, LI Weihong. Physiological response of riparian plants to watering in hyper-arid areas of Tarim River, China. Front. Biol., 2007, 2(1): 54-61.
