Pedosphere 25(3): 459--467, 2015
ISSN 1002-0160/CN 32-1315/P
©2015 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Osmotic adjustment of soil biocrust mosses in response to desiccation stress |
ZHAO Xin1,2 , SHI Yong1,2, LIU Yang1,2, JIA Rong-Liang1,2 and LI Xin-Rong1,2 |
1Key Laboratory of Stress Physiology and Ecology, Gansu Province, Lanzhou 730000 (China)
2Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000 (China) |
| ABSTRACT |
| Biological soil crusts (biocrusts) widely occur in semiarid and arid regions throughout the world and play important roles in many desert ecosystems: protecting soil from wind erosion and detaining nutrient-rich dust and organic carbon. An experiment was conducted in the Shapotou revegetated area of the Tengger Desert, Ningxia Hui Autonomous Region of China to investigate the physiological responses of the dominant biocrust mosses, Bryum argenteum and Didymodon vinealis, to desiccant stress using different osmotic adjustments. B. argenteum and D. vinealis accumulated K+, total soluble sugar, sucrose, trehalose, proline, and glycine betaine during desiccation. The proline content of B. argenteum was about two times higher than that of D. vinealis. The K+ and glycine betaine contents in B. argenteum were slightly higher than those in D. vinealis. In contrast, the total soluble sugar, sucrose, and trehalose contents in D. vinealis were about 3 to 5 times higher than those in B. argenteum. With gradual desiccation stress, the Na+ content of B. argenteum was low and did not significantly change. On the contrary, the Na+ content of D. vinealis sharply increased and reached a very high level of about 10 to 18 times higher than that of B. argenteum, indicating that B. argenteum and D. vinealis gradually adapted to desiccation stress by osmotic substances accumulation to different degrees. |
| Key Words: biological soil crusts, Bryum argenteum, compatible solute, Didymodon vinealis, drought stress |
| Citation: Zhao, X., Shi, Y., Liu, Y., Jia, R. L. and Li, X. R. 2015. Osmotic adjustment of soil biocrust mosses in response to desiccation stress. Pedosphere. 25(3): 459-467. |
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