《植物生理学报》 2021, 57(2): 480-492

NO₃^-缓解小麦NH₄⁺胁迫的生理机制研究

张燕^1,2，张云秀²，吕雪梅^1,2，杜琬莹^1,2，冯波²，李华伟²，王宗帅²，夏海勇^1,2，樊守金¹，孔令安^1,2,*

¹山东师范大学生命科学学院, 济南250014；²山东省农业科学院作物研究所, 济南250100

通信作者：孔令安；E-mail: kongling-an@163.com

摘　要：

本实验研究了NO₃^-对单一NH₄⁺胁迫下小麦(Triticum aestivum)根系生理特性的响应机制。结果表明: 单一NH₄⁺处理下, 与对照相比, 根系鲜重显著降低; 吲哚乙酸(IAA)和茉莉酸含量显著降低, 水杨酸含量显著升高; 抗氧化酶活性显著降低, 活性氧与丙二醛含量显著升高; 氮代谢酶活性显著降低, 谷氨酰胺含量显著增加。傅里叶转换红外光谱检测表明, 纤维素、木质素等峰值增大, 其含量也显著升高。非损伤微测结果表明, NH₄⁺、 H⁺外排速率以及IAA内流速率增加。 NH₄⁺+NO₃^-处理能提高小麦根系IAA、茉莉酸等激素含量,降低水杨酸含量, 提高抗氧化酶与氮代谢关键酶活性, 降低NH₄⁺、 H⁺外排速率以及细胞壁结构性成分的含量, 从而缓解NH₄⁺抑制作用。综上所述, NH₄⁺+NO₃^-处理有效缓解了单一NH₄⁺处理对小麦根系的抑制作用。

关键词：单一NH4+胁迫; 氮代谢酶; 激素; 抗氧化酶; NO3 −; 小麦

收稿：2020-05-13   修定：2020-12-23

资助：山东省自然科学基金(ZR2020MC087)、山东省农业科技资金(园区产业提升工程)项目(2019YQ001)、国家重点研发计划项目 (2017YFD0300203和2018YFD0300601)、山东省现代农业产业技术体系项目(SDAIT-01-06)和国家现代农业产业技术体系项目 (CARS-3-1-21)

Study on physiological mechanism of NO₃^- alleviating NH₄⁺ stress in wheat

ZHANG Yan^1,2, ZHANG Yunxiu², LÜ Xuemei^1,2, DU Wanying^1,2, FENG Bo², LI Huawei², WANG Zongshuai², XIA Haiyong^1,2, FAN Shoujin¹, KONG Ling’an^1,2,*

¹College of Life Science, Shandong Normal University, Jinan 250014, China; ²Crop Research Institute, Shandong Academy of Agricultural Sciences, Jinan 250100, China

Corresponding author: KONG Ling’an; E-mail: kongling-an@163.com

Abstract:

In this study, we investigated the mechanism underlying which NO₃^- alleviates the NH₄⁺ stress upon root growth in wheat (Triticum aestivum). The results showed that the fresh weight of root was signifcantly reduced, the indoleacetic acid (IAA) and jasmonic acid contents were signifcantly decreased, and the salicylic acid content was signifcantly increased in roots of wheat plants under single NH₄⁺ treatment compared to the control. Meanwhile, the activities of antioxidant enzymes were significantly decreased and the contents of reactive oxygen species and malondialdehyde were signifcantly increased. The activities of nitrogen metabolism enzymes decreased and the content of glutamine were signifcantly increased. Fourier transform infrared determination showed that the peak values and contents of cellulose and lignin were signifcantly increased. Assay using non-invasive micro-test technology showed that the rates of NH₄⁺ and H⁺ efux and IAA influx were increased. NH₄⁺ + NO₃^- treatment increased the contents of IAA, jasmonic acid and salicylic acid, improved the activities of antioxidant enzymes and key nitrogen metabolism enzymes, reduced the rate of NH₄⁺ and H⁺ efux, and decreased the contents of structural components in the cell wall, so as to alleviate the inhibitory effect of NH₄⁺. In conclusion, NH₄⁺ + NO₃^- treatment effectively alleviated the inhibitory effect of single NH₄+ treatment on the root growth in wheat.

Key words: single NH4+ stress; nitrogen metabolism enzyme; hormone; antioxidant enzyme; NO3−; wheat