Antioxidant enzymes in plants are critical for protection against oxidative stress and for the overall health and resilience of plant systems. However, antioxidant responses of plants grown in shallow and saline groundwater are poorly understood. Therefore, understanding the biochemical responses of plants to shallow groundwater significantly affects food security and environmental conservation. With this aim, the present work was carried out for 2 years in drainable lysimeters to assess the effects of four different groundwater salinities (0.38, 2.0, 4.0 and 8.0 dS m−1) on the temporal changes in antioxidant enzymatic activity in wheat plants under three different groundwater depths (30, 55 and 80 cm). Superoxide dismutase (SOD), glutathione S‐transferase (GST) and catalase (CAT) activities varied significantly based on groundwater depth and salinity. CAT and GST enzyme levels increased curvilinearly with rising groundwater depth and salinity. Conversely, the GR enzyme activity showed no significant change with groundwater depths but increased linearly with higher salinity. SOD enzyme activity notably increased at a groundwater depth of 30 cm but decreased at a depth of 80 cm. Moreover, the peak activity of the GR enzyme was observed at a 6 dS m−1 groundwater salinity under groundwater depths. Additionally, the GST and CAT enzyme activities were inhibited more when the groundwater depth was <55 cm and the groundwater salinity was >4.20 dS m−1. Finally, identifying the peak levels of antioxidant enzymes could potentially serve as an indicator for determining the optimal timing for applying stress mitigation methods in areas with shallow and saline groundwater.

中文翻译：

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冬小麦（Triticum aestivum L.）抗氧化酶对浅层和含盐地下水深度的响应


植物中的抗氧化酶对于防止氧化应激以及植物系统的整体健康和恢复力至关重要。然而，人们对生长在浅层和咸地下水中的植物的抗氧化反应知之甚少。因此，了解植物对浅层地下水的生化反应显着影响粮食安全和环境保护。为此，本研究在可排水渗漏计中进行了两年，以评估四种不同地下水盐度（0.38、2.0、4.0 和 8.0 dS m−1）对小麦植株抗氧化酶活性随时间变化的影响。三种不同的地下水深度（30、55 和 80 厘米）。超氧化物歧化酶（SOD）、谷胱甘肽 S-转移酶（GST）和过氧化氢酶（CAT）活性根据地下水深度和盐度而显着变化。 CAT 和 GST 酶水平随着地下水深度和盐度的增加呈曲线增加。相反，GR酶活性随地下水深度没有显着变化，但随着盐度的升高而线性增加。 SOD酶活性在地下水深度30 cm时显着升高，但在80 cm深度时降低。此外，在地下水深处地下水盐度为 6 dS m−1 时观察到 GR 酶的峰值活性。此外，当地下水深度为<55 cm、地下水盐度为>4.​​20 dS m−1时，GST和CAT酶活性受到更多抑制。最后，确定抗氧化酶的峰值水平可以作为确定在浅层和咸地下水地区应用压力缓解方法的最佳时机的指标。