Institute of Crop Science, Ministry of Agriculture and Rural Affairs Laboratory of Spectroscopy Sensing, Zhejiang University, Hangzhou, China.
Institute of Crop Science, Quzhou Academy of Agricultural Sciences, Quzhou, China.
Physiol Plant. 2021 Jun;172(2):1133-1148. doi: 10.1111/ppl.13375. Epub 2021 Mar 5.
Climate change, food insecurity, water scarcity, and population growth are some of today's world's frightening problems. Drought stress exerts a constant threat to field crops and is often seen as a major constraint on global agricultural productivity; its intensity and frequency are expected to increase in the near future. The present study investigated the effects of drought stress (15% w/v polyethylene glycol PEG-6000) on physiological and biochemical changes in five Brassica napus cultivars (ZD630, ZD622, ZD619, GY605, and ZS11). For drought stress induction, 3-week-old rapeseed oil seedlings were treated with PEG-6000 in full strength Hoagland nutrient solution for 7 days. PEG treatment significantly decreased the plant growth and photosynthetic efficiency, including primary photochemistry (Fv/Fm) of PSII, intercellular CO , net photosynthesis, chlorophyll contents, and water-use efficiency of all studied B. napus cultivars; however, pronounced growth retardations were observed in cultivar GY605. Drought-stressed B. napus cultivars also experienced a sharp rise in H O generation and malondialdehyde (MDA) content. Additionally, the accumulation of ROS was accompanied by increased activity of enzymatic antioxidants (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase), although the increase was more obvious in ZD622 and ZS11. Drought stress also caused an increased endogenous hormonal biosynthesis (abscisic acid, jasmonic acid, salicylic acid) and accumulation of total soluble proteins and proline content, but the extent varies in B. napus cultivars. These results suggest that B. napus cultivars have an efficient drought stress tolerance mechanism, as shown by improved antioxidant enzyme activities, photosynthetic and hormonal regulation.
气候变化、粮食不安全、水资源短缺和人口增长是当今世界面临的一些可怕问题。干旱胁迫对大田作物构成持续威胁，通常被视为全球农业生产力的主要制约因素；预计在不久的将来，其强度和频率将会增加。本研究调查了干旱胁迫（15%w/v 聚乙二醇 PEG-6000）对 5 个甘蓝型油菜品种（ZD630、ZD622、ZD619、GY605 和 ZS11）生理生化变化的影响。为了诱导干旱胁迫，用 PEG-6000 处理 3 周龄油菜幼苗，在全强度 Hoagland 营养液中处理 7 天。PEG 处理显著降低了植物生长和光合作用效率，包括 PSII 的原初光化学（Fv/Fm）、胞间 CO2、净光合作用、叶绿素含量和所有研究的甘蓝型油菜品种的水分利用效率；然而，在品种 GY605 中观察到明显的生长迟缓。干旱胁迫的甘蓝型油菜品种也经历了 H2O2 生成和丙二醛（MDA）含量的急剧上升。此外，ROS 的积累伴随着酶抗氧化剂（超氧化物歧化酶、过氧化物酶、过氧化氢酶、抗坏血酸过氧化物酶、谷胱甘肽还原酶和单脱氢抗坏血酸还原酶）活性的增加，尽管在 ZD622 和 ZS11 中增加更为明显。干旱胁迫还导致内源激素生物合成（脱落酸、茉莉酸、水杨酸）和总可溶性蛋白和脯氨酸含量的增加，但在甘蓝型油菜品种中有所不同。这些结果表明，甘蓝型油菜品种具有有效的干旱胁迫耐受机制，表现为抗氧化酶活性、光合作用和激素调节的提高。
