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Adzuki bean, an important legume crop, exhibits poor tolerance to low temperatures. To investigate the effect of exogenous abscisic acid (ABA) on the physiological metabolism and yield resistance of adzuki bean under low-temperature stress, we conducted a potted experiment using Longxiaodou 4 (LXD 4) and Tianjinhong (TJH) as test materials and pre-sprayed with exogenous ABA at flowering stage continuously for 5 days with an average of 12°C and an average of 15°C, respectively. We found that, compared with spraying water, foliar spraying exogenous ABA increased the activities of antioxidants and the content of non-enzymatic antioxidants, effectively inhibited the increase of malondialdehyde (MDA), hydrogen peroxide (H2O2) content, O2-· production rate. Exogenous ABA induced the activation of endogenous protective mechanisms by increasing antioxidant enzymes activities such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as elevated levels of non-enzymatic antioxidants including ascorbic acid (ASA) and glutathione (GSH). Moreover, the yield loss of 5.81%-39.84% caused by chilling stress was alleviated by spraying ABA. In conclusion, foliar spraying exogenous ABA can reduce the negative effects of low-temperature stress on the yield of Adzuki beans, which is essential to ensure stable production of Adzuki beans under low-temperature conditions.

小豆作为重要的豆科作物，对低温胁迫的耐受性较差。为探究外源脱落酸（abscisic acid, ABA）对低温胁迫下小豆生理代谢与产量抗逆性的影响，本研究以‘陇小豆4号’（Longxiaodou 4, LXD 4）和‘天津红’（Tianjinhong, TJH）为试验材料开展盆栽试验，分别在日均温12℃与15℃的环境中，于开花期连续5天喷施外源ABA。研究结果表明，与喷施清水的对照组相比，叶面喷施外源ABA可提升抗氧化系统活性与非酶类抗氧化物质含量，有效抑制丙二醛（malondialdehyde, MDA）、过氧化氢（hydrogen peroxide, H₂O₂）含量及超氧阴离子（O₂·）产生速率的上升。外源ABA可通过提升超氧化物歧化酶（superoxide dismutase, SOD）、过氧化物酶（peroxidase, POD）、过氧化氢酶（catalase, CAT）等抗氧化酶活性，以及抗坏血酸（ascorbic acid, ASA）、谷胱甘肽（glutathione, GSH）等非酶类抗氧化物质的水平，诱导内源保护机制的激活。此外，喷施ABA可缓解低温胁迫造成的5.81%~39.84%的产量损失。综上，叶面喷施外源ABA可降低低温胁迫对小豆产量的负面影响，对保障低温环境下小豆的稳产具有重要意义。