Qinghai-Tibet plateau as an alpine and high-altitude area is frequently confronted with freeze-thaw stress. Recently, due to the change of global climate, the drought and salinization of soil in this area have become increasingly serious, together with low temperature, and constitute the main limiting factors for crop growth in this area. Physiological responses of blue barley to salinization (S), drought (D), and freeze-thaw (F) stress were studied. Through applying 100 mmol/L NaCl, 15% drought and freeze-thaw cycle (10, − 5, 10 °C) stress, the changes of relative water content (RWC), soluble protein, malondialdehyde (MDA), superoxide dismutase (SOD), and peroxidase (POD) in seedling leaves of 8 treatment groups (CK, S, D, DS, F, FD, FS, and FDS) were analyzed. The results showed that single stress, either NaCl, drought, or freeze-thaw, could lead to the decrease of RWC and the increase of not only the soluble protein and MDA content, but also the SOD and POD activity in leaves. During the freeze-thaw cycle, the soluble protein, MDA content, SOD, and POD activity of seedlings increased at first and gradually decreased, while RWC gradually decreased with the change of temperature. The research indicated that there were synergistic effects among the stresses of drought, NaCl, and freeze-thaw on the plant, and the compound stress could cause more serious effect on the plant compared with the single one.

中文翻译：

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青稞幼苗对NaCl、干旱和冻融胁迫的生理反应

青藏高原作为高寒高海拔地区，经常面临冻融胁迫。近年来，受全球气候变化影响，该地区土壤干旱、盐渍化日益严重，气温偏低，已成为该地区农作物生长的主要限制因素。研究了蓝大麦对盐渍化 (S)、干旱 (D) 和冻融 (F) 胁迫的生理反应。通过施加100 mmol/L NaCl、15%干旱和冻融循环（10, − 5, 10 °C）胁迫，相对含水量（RWC）、可溶性蛋白、丙二醛（MDA）、超氧化物歧化酶（SOD）的变化) 和 8 个处理组 (CK、S、D、DS、F、FD、FS 和 FDS) 幼苗叶片中的过氧化物酶 (POD) 进行了分析。结果表明，单一的胁迫，无论是氯化钠、干旱还是冻融，可导致RWC降低，可溶性蛋白和MDA含量增加，叶片SOD和POD活性增加。在冻融循环过程中，幼苗的可溶性蛋白、MDA含量、SOD和POD活性先升高后逐渐降低，而RWC则随着温度的变化而逐渐降低。研究表明，干旱、NaCl、冻融等胁迫对植株具有协同作用，复合胁迫对植株的影响较单一胁迫更为严重。而RWC随着温度的变化而逐渐减小。研究表明，干旱、NaCl、冻融等胁迫对植株具有协同作用，复合胁迫对植株的影响较单一胁迫更为严重。而RWC随着温度的变化而逐渐减小。研究表明，干旱、NaCl、冻融等胁迫对植株具有协同作用，复合胁迫对植株的影响较单一胁迫更为严重。