Pedosphere 22(6): 803--814, 2012
ISSN 1002-0160/CN 32-1315/P
©2012 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Response of organic acids to zinc homeostasis in zinc-deficient and zinc-toxic apple rootstock roots |
LIU Di, LIU Ai-Hong, HE Chen, WANG Jin-Hua and WANG Yan-An |
| State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai'an 271018 (China) |
| ABSTRACT |
| To elucidate the mechanisms of tolerance to zinc (Zn) deficiency and Zn toxicity in the root of apple trees, the apple rootstock Malus hupehensis (Pamp.) Rehd seedlings were selected to study the responses of organic acids to Zn homeostasis in roots under low Zn (0 μmol L-1), adequate Zn (as control, 4 μmol L-1) and toxic Zn (100 μmol L-1) treatments. The differences of Zn concentrations and accumulations in the roots were highest, compared with those in the stems and leaves, when apple seedlings were subjected to low and toxic Zn treatments for 1 d. The concentrations and accumulations of oxalic and malic acids in the roots in the low and toxic Zn treatments increased by 20% to 60% compared with those of the control treatment. Significantly negative correlations were found between the total Zn concentrations and the concentrations of oxalic and malic acids in the roots under 1 d of low Zn treatment. However, contrary correlations were found for the toxic Zn treatment. Meanwhile, the maximum influx rates of Zn2+ under low and toxic Zn treatments increased by 30% and 20%, respectively, compared with the rate of the control treatment. Both Zn deficiency and Zn toxicity increased the concentrations of organic acids in root after short-time Zn treatment, which could resist Zn stress through balanding Zn homeostasis in M. hupehensis Rehd. |
| Key Words: Malus hupehensis (Pamp.) Rehd, Zn compartmentation, Zn deficiency, Zn toxicity, Zn uptake |
| Citation: Liu, D., Liu, A. H., He, C., Wang, J. H. and Wang, Y. A. 2012. Response of organic acids to zinc homeostasis in zinc-deficient and zinc-toxic apple rootstock roots. Pedosphere. 22(6): 803-814. |
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