State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Wuxi, 214122, China.
Planta. 2021 Jul 29;254(2):41. doi: 10.1007/s00425-021-03679-0.
Exogenous calcium enhances rice tolerance to acid rain stress by regulating isozymes composition and transcriptional expression of ascorbate peroxidase and glutathione reductase. Calcium (Ca) participates in signal transduction in plants under abiotic stress, and addition of Ca is beneficial to alleviate damage of plants caused by acid rain. To clarify the effect of exogenous Ca on tolerance of plants to acid rain stress, we investigated regulation of Ca (5 mM) on activities, isozymes composition and transcriptional expression of ascorbate peroxidase (APX) and glutathione reductase (GR), redox state, and HO concentration and growth in rice leaves and roots under simulated acid rain (SAR) stress. SAR (pH 3.5/2.5) decreased the total activities of APX and GR in rice by decreasing the concentration of APX isoforms (APXII in leaves and APXIII in roots) as well as activation degree of GR isozymes and transcription level of GR1, indicating that SAR (pH 3.5/2.5) destroyed the redox state in rice cells and induced HO excessive accumulation, and inhibited growth of rice. Exogenous Ca alleviated SAR-induced inhibition on activities of APX and GR by regulating the concentration, activation, and transcription of their isozymes, and then maintained the redox level of cells and protected cells from oxidative damage, being beneficial to the growth of rice. Therefore, the promotion of exogenous Ca on activities of APX and GR can be important to enhance rice tolerance to acid rain by maintaining redox state and avoiding oxidative damage.
外源钙通过调节抗坏血酸过氧化物酶和谷胱甘肽还原酶的同工酶组成和转录表达来增强水稻对酸雨胁迫的耐受性。钙（Ca）参与植物在非生物胁迫下的信号转导，添加 Ca 有利于缓解酸雨对植物造成的损害。为了阐明外源 Ca 对植物耐受酸雨胁迫的影响，我们研究了 Ca（5 mM）对模拟酸雨（SAR）胁迫下水稻叶片和根系中抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）的活性、同工酶组成和转录表达、氧化还原状态、HO 浓度和生长的调节作用。SAR（pH 3.5/2.5）通过降低 APX 同工型（叶片中的 APXII 和根中的 APXIII）的浓度以及 GR 同工型的激活程度和 GR1 的转录水平，降低了水稻中 APX 和 GR 的总活性，表明 SAR（pH 3.5/2.5）破坏了水稻细胞的氧化还原状态并诱导 HO 过度积累，从而抑制了水稻的生长。外源 Ca 通过调节同工酶的浓度、激活程度和转录水平，缓解了 SAR 诱导的 APX 和 GR 活性抑制，从而维持了细胞的氧化还原水平，保护细胞免受氧化损伤，有利于水稻的生长。因此，外源 Ca 对 APX 和 GR 活性的促进作用对于通过维持氧化还原状态和避免氧化损伤来增强水稻对酸雨的耐受性可能很重要。
