Kaneko Toshiyuki, Horie Tomoaki, Nakahara Yoshiki, Tsuji Nobuya, Shibasaka Mineo, Katsuhara Maki
Institute of Plant Science and Resources, Okayama University, 20-1, Chuo-2-chome, Kurashiki, Okayama, 710-0046 Japan Department of Physiology, Asahikawa Medical University, 2-1-1-1, Midorigaoka-higashi, Asahikawa, Hokkaido, 078-8510 Japan These authors contributed equally to this work.
Institute of Plant Science and Resources, Okayama University, 20-1, Chuo-2-chome, Kurashiki, Okayama, 710-0046 Japan Division of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, 3-15-1, Tokida, Ueda, Nagano, 386-8567 Japan These authors contributed equally to this work.
Plant Cell Physiol. 2015 May;56(5):875-82. doi: 10.1093/pcp/pcv013. Epub 2015 Jan 28.
Salinity stress significantly reduces the root hydraulic conductivity (Lpr) of several plant species including barley (Hordeum vulgare). Here we characterized changes in the Lpr of barley plants in response to salinity/osmotic stress in detail using a pressure chamber. Salt-tolerant and intermediate barley cultivars, K305 and Haruna-nijyo, but not a salt-sensitive cultivar, I743, exhibited characteristic time-dependent Lpr changes induced by 100 mM NaCl. An identical response was evoked by isotonic sorbitol, indicating that this phenomenon was triggered by osmotic imbalances. Further examination of this mechanism using barley cv. Haruna-nijyo plants in combination with the use of various inhibitors suggested that various cellular processes such as protein phosphorylation/dephosphorylation and membrane internalization appear to be involved. Interestingly, the three above-mentioned barley cultivars did not exhibit a remarkable difference in root cell sap osmolality under hypertonic conditions, in contrast to the case of Lpr. The possible biological significance of the regulation of Lpr in barley plants upon salinity/osmotic stress is discussed.
盐分胁迫显著降低了包括大麦（Hordeum vulgare）在内的几种植物的根系水力导度（Lpr）。在此，我们使用压力室详细表征了大麦植株Lpr响应盐分/渗透胁迫的变化。耐盐和中等耐盐的大麦品种K305和春阳二号，但盐敏感品种I743未表现出由100 mM NaCl诱导的特征性Lpr随时间的变化。等渗山梨醇引发了相同的反应，表明这种现象是由渗透失衡触发的。使用大麦品种春阳二号植株并结合各种抑制剂对该机制进行进一步研究表明，蛋白质磷酸化/去磷酸化和膜内化等各种细胞过程似乎都参与其中。有趣的是，与Lpr的情况相反，上述三个大麦品种在高渗条件下根细胞液渗透压并未表现出显著差异。本文讨论了盐分/渗透胁迫下大麦植株Lpr调节的可能生物学意义。
