Nitrogen metabolism and antioxidant system responses of Suaeda salsa to nitrogen addition

ABSTRACT

There are serious problems with degradation of Suaeda salsa (S. salsa) in Liaohe estuary wetland, Liaodong Bay, Northeast China, which may be mainly caused by the high nitrogen runoff of the upstream ecosystem. This study investigated the effect of nitrogen addition on the nitrogen transformation of S. salsa and soil by ¹⁵N labeling technology and the oxidative stress to S. salsa, thereby exploring the cause of the degradation. The dry weight (by 45.2%–67.3%) of S. salsa and the abundance of ammonium monooxygenase (amoB) (by 62%–75%) gene in soil decreased under high concentration of nitrogen conditions. The dissolved organic nitrogen (DON) (by 3%–14.2%) and total nitrogen (TN) (by 75%–89.7%) content in soil increased with increasing nitrogen addition. The hydrogen peroxide (by 5.9%–14.6%) and malondialdehyde (MDA) (by 9.6%–14.7%) content of S. salsa increased with increasing nitrogen addition. Therefore, high concentration of nitrogen not only decreased the biomass of S. salsa but also caused the waste of nitrogen source. High concentration of nitrogen weakened the nitrification of soil microorganisms and caused oxidative stress to S. salsa. The addition of high concentration of nitrogen was evidenced to be one of the main reasons for the degradation of S. salsa in the present study.

KEYWORDS:

• Enzymatic activity
• nitrogen transformation
• oxidative stress
• S. salsa

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

Conceptualization, Methodology, Validation, Formal analysis, Investigation, Data Curation, Writing-Original Draft, Writing-Review & Editing and Visualization: Shuyuan Wang; Conceptualization and Funding acquisition: Yu Liu; Validation and Investigation: Xiangfeng Ma; Data Curation: Qingqing Jiang; Investigation: Guoguang Wang.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.

Additional information

Funding

This work was supported by the [Liaoning Revitalization Talents Program] under Grant [XLYC2001002].