Effects of salt stress levels on nutritional quality and microorganisms of alfalfa-influenced soil

Qiang Lu; GenTu Ge; DuoWen Sa; ZhiJun Wang; MeiLing Hou; Yu Shan Jia

doi:10.7717/peerj.11729

Effects of salt stress levels on nutritional quality and microorganisms of alfalfa-influenced soil

PeerJ. 2021 Jul 14:9:e11729. doi: 10.7717/peerj.11729. eCollection 2021.

Authors

Qiang Lu¹, GenTu Ge¹, DuoWen Sa¹, ZhiJun Wang¹, MeiLing Hou², Yu Shan Jia¹

Affiliations

¹ College of Grassland and Resources and Environment, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia Autonomous Region, China.
² College of Agriculture, Inner Mongolia University for Nationalities, Tongliao, Inner Mongolia Autonomous Region, China.

Abstract

Background: Globally, there is a large amount of salinized land. These soils have varying degrees of salt stress, causing ionic toxicity and osmotic stress on plants. However, it is not clear how different degrees of salt stress affect plant nutrients and microbial communities. Thus, a comprehensive understanding of plant major nutrients and microbial communities response to salt stress is desirable.

Results: We analyzed the main nutrients of the salt-tolerant ZhongMu No. 3 alfalfa variety planted in a salt stress environment. In mild and moderate group, the protein content and fatty acid content of alfalfa were the highest, indicating the best nutritional value. The severe group of salt stress affected the growth and development of alfalfa, as manifested by a decrease in the nutritional quality of alfalfa. Pseudomonas and Sphingobacterium that from alfalfa stem and leaf endophytes also increased with an increase in salt stress. In contrast, Sphingomonas, Methylobacterium, and Rhizobium decrease with increasing salt stress. Methylobacterium and Rhizobium have extremely significant differences in response to salt stress, and Exiquobacterium also shows significant differences.

Conclusions: Soil salinity would be an important factor beyond which alfalfa nutrient quality and microbial community structure change. This study identified key levels of salt stress that may affect the nutrient quality and microbial community structure. These findings enhance our understanding of the effects of salt stress on the nutritional quality of alfalfa and provide a reference for the sustainable use of salinized soil in the future.

Keywords: Alfalfa; Microorganism; Protein; Salt stress.

Grants and funding

This study was supported by the National key research and development plan (2016YFC0501308), the National Technical System of Forage Industry for Dry Grass Storage (CARS-34), and the Inner Mongolia Autonomous Region Science and Technology Plan Project of China (201802069). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.