College of Horticulture, Northwest A&F University, Yangling, 71210, China.
Horticultural Research Institute, National Agricultural Research Centre, Islamabad, 44000, Pakistan.
Plant Biol (Stuttg). 2021 Sep;23(5):785-796. doi: 10.1111/plb.13276. Epub 2021 Jun 2.
Low temperature (LT) and high humidity (HH) are important environmental factors in greenhouses and plastic tunnels during the cold season, as they hamper plant growth and development. Here, we studied the effect of LT (day/night: 9/5 °C, 25/18 °C as control) and HH (95%, 80% as control) on young cucumber plants at the 2, 4 or 6 leaf stages. LT+HH stress resulted in a decline in shoot, root and total fresh and dry weights, and decreased P , g , T , F /F , qP, ETR and chlorophyll, and increased MDA, H O , O , NPQ and C as compared to the control at the 2 leaf stage. SOD, POD, CAT, APX and GR were upregulated under LT+HH stress as compared to the control at the 6 leaf stage. ABA and JA increased under LT+HH stress as compared to the control at the 6 leaf stage, while IAA and GA decreased under LT+HH stress as compared to the control at the 2 leaf stage. Our results show that LT+HH stress affects young cucumber plant photosynthetic efficiency, PSII activity, antioxidant defence system, ROS and hormone profile. Plants at the 6 leaf stage were more tolerant than at the 2 and 4 leaf stages under stress conditions.
低温（LT）和高湿度（HH）是寒冷季节温室和塑料大棚中的重要环境因素，因为它们会阻碍植物的生长和发育。在这里，我们研究了 LT（白天/夜晚：9/5°C，25/18°C 为对照）和 HH（95%，80%为对照）对 2、4 或 6 叶期的年轻黄瓜植株的影响。与对照相比，LT+HH 胁迫导致植株的茎、根和总鲜重和干重下降，叶片的 P、g、T、F/F、qP、ETR 和叶绿素含量降低，而 MDA、H2O2、O2-、NPQ 和 C 含量增加。与对照相比，在 6 叶期，SOD、POD、CAT、APX 和 GR 的表达水平在 LT+HH 胁迫下上调。与对照相比，ABA 和 JA 在 LT+HH 胁迫下增加，而 IAA 和 GA 在 LT+HH 胁迫下减少。研究结果表明，LT+HH 胁迫影响年轻黄瓜植株的光合作用效率、PSII 活性、抗氧化防御系统、ROS 和激素水平。与对照相比，在胁迫条件下，处于 6 叶期的植株比处于 2 叶期和 4 叶期的植株更耐受。
