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草业学报 ›› 2024, Vol. 33 ›› Issue (7): 182-191.DOI: 10.11686/cyxb2023314

• 研究论文 • 上一篇    

缺氮条件下内生真菌对醉马草生理特性的影响

邓茂桦(), 郑蓉(), 王蓓晨, 王超, 刘荣贵, 张瀚文, 王政和, 王剑峰()   

  1. 兰州大学草地农业科技学院,草地微生物研究中心,草种创新与草地农业生态系统全国重点实验室,甘肃 兰州 730020
  • 收稿日期:2023-09-01 修回日期:2023-11-03 出版日期:2024-07-20 发布日期:2024-04-08
  • 通讯作者: 王剑峰
  • 作者简介:E-mail: wangjf12@lzu.edu.cn
    邓茂桦(2002-),男,四川南充人,在读本科。E-mail: dengmh20@lzu.edu.cn
    郑蓉(2000-),女,甘肃榆中人,在读硕士。E-mail: 220220901690@lzu.edu.cn第一联系人:共同第一作者These authors contributed equally to this work.
  • 基金资助:
    国家自然科学基金(32001399);兰州大学中央高校基础研究基金(lzujbky-2021-ey01)

Effects of the Epichloë gansuensis endophyte on the physiological status of Achnatherum inebrians under different nitrogen concentrations

Mao-hua DENG(), Rong ZHENG(), Bei-chen WANG, Chao WANG, Rong-gui LIU, Han-wen ZHANG, Zheng-he WANG, Jian-feng WANG()   

  1. College of Pastoral Agriculture Science and Technology,Lanzhou University,Center for Grassland Microbiome,State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems,Lanzhou 730020,China
  • Received:2023-09-01 Revised:2023-11-03 Online:2024-07-20 Published:2024-04-08
  • Contact: Jian-feng WANG

摘要:

氮是植物生长发育阶段必不可少的大量元素之一,内生真菌可以通过与醉马草形成共生体进而影响宿主氮代谢。内生真菌对宿主氮代谢的影响与周围环境氮浓度密切相关。本研究以携带Epichlo? gansuensis内生真菌(E+)的醉马草和未携带E. gansuensis内生真菌(E-)的醉马草为材料,设置低氮(0.01 mmol·L-1 N)和正常氮浓度(7.5 mmol·L-1 N)两种生长条件,对醉马草进行为期6个月的处理,收获试验材料后测定了醉马草的叶片干重,过氧化氢(H2O2)含量,丙二醛(MDA)含量等指标并进行分析,主要研究结果如下:1) N营养贫瘠条件下,内生真菌的侵染显著增加了醉马草植株的株高、叶片干重、分蘖数、葡萄糖-6-磷酸脱氢酶(G6PDH)活性、还原性谷胱甘肽(GSH)含量和N含量,显著降低了醉马草植株的MDA和H2O2含量,而对醉马草植株叶片的C和P含量以及C∶N,C∶P,N∶P无显著影响;2) 正常N营养条件下,内生真菌的侵染仅显著增加了E+醉马草植株的株高,而对叶片干重、分蘖数、MDA、H2O2含量、GSH和G6PDH活性均无显著影响。综上所述,本研究初步探明了内生真菌的侵染可以通过增加醉马草G6PDH活性和GSH的含量,降低醉马草H2O2和MDA含量,促进氮的吸收,增加了叶片干重和分蘖数,以此改善了醉马草在低氮条件下的生长,而对正常氮营养条件下的植株影响有限。

关键词: 醉马草, 内生真菌, 氮浓度, 生理特性

Abstract:

Nitrogen is an essential macronutrient for plant growth and development, and endophytic fungi can influence nitrogen metabolism in the host. The endophyte Epichlo? gansuensis forms a symbiotic relationship with Achnatherum inebrians, also known as drunken horse grass. The effect of endophytic fungi on the host’s nitrogen metabolism is dependent on the surrounding nitrogen concentrations. In this study, A. inebrians plants infected with the Epichlo? gansuensis endophyte (E+) or not infected (E-) were grown under low (0.01 mmol·L–1 N) and normal (7.5 mmol·L–1 N) nitrogen levels for 6 months. The harvested materials were analyzed to determine leaf dry weight, hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content, and other physiological and biochemical indices. The results revealed that: 1) Under low-nitrogen conditions, compared with E- A. inebrians plants, E+ A. inebrians plants showed significantly increased plant height, dry weight, tiller number, glucose-6-phosphate dehydrogenase (G6PDH) activity, reduced glutathione (GSH) content, and nitrogen content, and significantly decreased MDA and H2O2 contents. However, the carbon (C) and phosphorus (P) leaf contents, and the C∶N, C∶P, and N∶P ratios in the plants did not differ significantly between the E+ and E- plants. 2) Under normal-N conditions, compared with E- plants, E+ plants showed significantly increased plant height, but no significant difference in dry weight, tiller number, MDA and H2O2 contents, and GSH and G6PDH activity. Taken together, these findings suggest that E. gansuensis infection can enhance the growth of A. inebrians under low-nitrogen conditions by increasing G6PDH activity and GSH content, reducing H2O2 and MDA content, and promoting nitrogen uptake, thereby increasing leaf dry weight and tiller numbers. However, the impact of E. gansuensis on A. inebrians plants under normal N levels is limited.

Key words: Achnatherum inebrians, endophytic fungi, nitrogen concentrations, physiological status