Heterologous expression of fungal AcGDH alleviates ammonium toxicity and suppresses photorespiration, thereby improving drought tolerance in rice.
Heterologous expression of fungal AcGDH alleviates ammonium toxicity and suppresses photorespiration, thereby improving drought tolerance in rice.
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DOI：
10.1016/j.plantsci.2020.110769
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发表时间：
2021-04
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通讯作者：
Luan Yan;Yinyin Gong;Q. Luo;Gaoxing Dai;Zhenning Teng;Yong He;Xiangxia Wu;Cong Liu;Dong-Ying Tang;Nenghui Ye;Guofu Deng;Jian-Zhong Lin;Xuanming Liu
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文献类型：
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作者：
Luan Yan;Yinyin Gong;Q. Luo;Gaoxing Dai;Zhenning Teng;Yong He;Xiangxia Wu;Cong Liu;Dong-Ying Tang;Nenghui Ye;Guofu Deng;Jian-Zhong Lin;Xuanming Liu
干旱胁迫会显著影响植物生长和农业生产力。因此，探索和鉴定最佳基因对提高作物耐旱性至关重要。本研究从白曲霉中分离到一个依赖于NADP（H）的谷氨酸脱氢酶基因（AcGDH），并在水稻中异源表达。AcGDH对NH4+有很高的亲和力，能促进水稻对NH4+的同化，转AcGDH基因水稻表现出耐旱和耐碱的特性，其光呼吸受到明显抑制。我们的研究结果表明，AcGDH减轻铵毒性和抑制光呼吸，通过同化过量的NH 4+和破坏碳氮代谢的微妙平衡，从而提高水稻的耐旱性。此外，AcGDH不仅提高了幼苗期的耐旱性，而且还提高了干旱胁迫下的产量。因此，AcGDHis是一个很有希望的保持水稻籽粒产量的候选基因，并为干旱胁迫下作物产量的提高提供了机会。
Drought stress can significantly affect plant growth and agricultural productivity. Thus, it is essential to explore and identify the optimal genes for the improvement of crop drought tolerance. Here, a fungal NADP(H)-dependent glutamate dehydrogenase gene (AcGDH) was isolated fromAspergillus candidus, and heterologously expressed in rice. AcGDH has a high affinity for NH4+and increases the ammonium assimilation in rice.AcGDHtransgenic plants exhibited a tolerance to drought and alkali stresses, and their photorespiration was significantly suppressed. Our findings demonstrate that AcGDH alleviates ammonium toxicity and suppresses photorespiration by assimilating excess NH4+and disturbing the delicate balance of carbon and nitrogen metabolism, thereby improving drought tolerance in rice. Moreover,AcGDHnot only improved drought tolerance at the seedling stage but also increased the grain yield under drought stress. Thus,AcGDHis a promising candidate gene for maintaining rice grain yield, and offers an opportunity for improving crop yield under drought stress.