Abstract：
Acid rain threatens crop yield and nutritional quality, and Ca2+ can regulate plant responses to abiotic stresses. To improve the yield and nutritional quality of crops under acid rain stress, we applied exogenous Ca2+ to regulate nitrogen assimilation in rice seedlings under simulated acid rain stress (pH 4.5 or 3.0), taking yield and nutritional quality of rice as evaluation criteria. We found that Ca2+ (5 mM) maintained the total nitrogen content of rice at the seedling and booting stages to alleviate the inhibitory effect of simulated acid rain on rice yield. Meanwhile, Ca2+ improved the activity of glutamate synthase to eliminate the disruption of glutamine synthetase/glutamate synthase balance under simulated acid rain. It decreased the efficiency of nitrogen assimilation, thereby reducing the inhibition of essential amino acid content in rice. The mitigation effect on simulated acid rain at pH 4.5 was better than that of simulated acid rain at pH 3.0. Overall, Ca2+ may reduce the negative effect of acid rain on the yield and nutritional quality of crops.
摘要：
酸雨威胁作物产量和营养品质,和Ca2+可以调节植物对非生物胁迫的反应。为提高酸雨胁迫下作物的产量和营养品质,在模拟酸雨胁迫（pH4.5或3.0）下，我们应用外源Ca2调节水稻幼苗的氮同化，以水稻产量和营养品质为评价标准。我们发现，Ca2（5mM）在幼苗和孕穗期保持了水稻的总氮含量，以减轻模拟酸雨对水稻产量的抑制作用。同时,Ca2+提高了谷氨酸合成酶的活性，消除了模拟酸雨下谷氨酰胺合成酶/谷氨酸合成酶平衡的破坏。它降低了氮同化的效率，从而降低了水稻中必需氨基酸含量的抑制作用。对pH4.5的模拟酸雨的缓解效果优于pH3.0的模拟酸雨。总的来说,Ca2+可以降低酸雨对作物产量和营养品质的负面影响。
