Abstract
Both arbuscular mycorrhizal (AM) fungi and root hairs play important roles in plant uptake of water and mineral nutrients. To reveal the relative importance of mycorrhiza and root hairs in plant water relations, a bald root barley (brb) mutant and its wild type (wt) were grown with or without inoculation of the AM fungus Rhizophagus intraradices under well-watered or drought conditions, and plant physiological traits relevant to drought stress resistance were recorded. The experimental results indicated that the AM fungus could almost compensate for the absence of root hairs under drought-stressed conditions. Moreover, phosphorus (P) concentration, leaf water potential, photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency were significantly increased by R. intraradices but not by root hairs, except for shoot P concentration and photosynthetic rate under the drought condition. Root hairs even significantly decreased root P concentration under drought stresses. These results confirm that AM fungi can enhance plant drought tolerance by improvement of P uptake and plant water relations, which subsequently promote plant photosynthetic performance and growth, while root hairs presumably contribute to the improvement of plant growth and photosynthetic capacity through an increase in shoot P concentration.
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Acknowledgments
We are very grateful to Dr. Iver Jakobsen for providing barley seeds and to Dr. Erik Verbruggen for his critical reading of the manuscript. The study was financially supported by the National Natural Science Foundation of China (41371264), Knowledge Innovation Program of the Chinese Academy of Sciences (Project no. KZCX2-YW-BR-17), and the National Key Technology R&D Program (2012BAC25B03).
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Tao Li and Ge Lin contributed equally to this work.
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Li, T., Lin, G., Zhang, X. et al. Relative importance of an arbuscular mycorrhizal fungus (Rhizophagus intraradices) and root hairs in plant drought tolerance. Mycorrhiza 24, 595–602 (2014). https://doi.org/10.1007/s00572-014-0578-3
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DOI: https://doi.org/10.1007/s00572-014-0578-3