Key Laboratory of Groundwater Resources and Environment of the Ministry of Education (Jilin University), Changchun, China; and Jilin Provincial Key Laboratory of Water Resources and Environment, Changchun, China; and College of New Energy and Environment, Jilin University, Changchun 130012, China.
Yushu Forestry and Grassland Comprehensive Service Center, No. 89, Qionglong East Road, Yushu City, Yushu Tibetan Autonomous Prefecture 815000, China.
Funct Plant Biol. 2024 Oct;51. doi: 10.1071/FP24205.
Freeze-thaw is a common stress at high altitudes in northern China. There is a risk of cadmium (Cd) contamination in the region. γ-aminobutyric acid (GABA) is a natural product that regulates plant growth. Rye (Secale cereale ) was used as research material to investigate the physiological effects of exogenous GABA on rye seedlings under the single and combined stresses of freeze-thaw and cadmium. The results showed that the combined stress severely inhibited shoot length, root length, fresh weight, and dry weight, increased malondialdehyde and hydrogen peroxide contents, and significantly decreased superoxide dismutase (SOD) activity. Foliar application of 5mM GABA alleviated the negative effects of stress on seedling growth, increased soluble protein content, and reduced malondialdehyde and hydrogen peroxide contents. Exogenous GABA application also enhanced the activities of SOD and peroxidase (POD). Additionally, the presence of exogenous GABA activated the GABA metabolic process and encouraged the accumulation of phytochelatins, glutathione, and non-protein thiol. These results indicate that exogenous GABA can effectively improve the resistance of rye seedlings to freeze-thaw and Cd by regulating the antioxidant enzyme system and enhancing its own detoxification mechanism, and they provide a basis for future applications of exogenous GABA, which is beneficial for ecological protection.
在中国北方高海拔地区，冻融是一种常见的胁迫。该地区存在镉（Cd）污染的风险。γ-氨基丁酸（GABA）是一种天然产物，可调节植物生长。黑麦（Secale cereale）被用作研究材料，以研究在冻融和镉单一及联合胁迫下外源 GABA 对黑麦幼苗的生理影响。结果表明，联合胁迫严重抑制了株高、根长、鲜重和干重，增加了丙二醛和过氧化氢的含量，显著降低了超氧化物歧化酶（SOD）活性。叶面喷施 5mM GABA 可减轻胁迫对幼苗生长的不利影响，增加可溶性蛋白含量，降低丙二醛和过氧化氢的含量。外源 GABA 的应用还增强了 SOD 和过氧化物酶（POD）的活性。此外，外源 GABA 的存在激活了 GABA 代谢过程，并促进了植物螯合肽、谷胱甘肽和非蛋白巯基的积累。这些结果表明，外源 GABA 通过调节抗氧化酶系统和增强自身解毒机制，可有效提高黑麦幼苗对冻融和 Cd 的抗性，为今后外源 GABA 的应用提供了依据，有利于生态保护。
