Diversity of nitrogen-fixing rhizobacteria associated with sugarcane: a comprehensive study of plant-microbe interactions for growth enhancement in Saccharum spp.

作者：Rajesh Kumar Singh, Pratiksha Singh, Hai-Bi Li, Qiqi Song, Dao-Jun Guo, Manoj Kumar Solanki, Krishan K. Verma, Mukesh Kumar Malviya, Xiu‐Peng Song, Prakash Lakshmanan, Li‐Tao Yang, Yang‐Rui Li · 发表于：BMC Plant Biology · 年份：2020 · DOI：10.1186/s12870-020-02400-9 · 被引用次数：180 · 研究领域：Plant-Microbe Interactions and Immunity、Legume Nitrogen Fixing Symbiosis、Sugarcane Cultivation and Processing

Abstract Background Nitrogen is an essential element for sugarcane growth and development and is generally applied in the form of urea often much more than at recommended rates, causing serious soil degradation, particularly soil acidification, as well as groundwater and air pollution. In spite of the importance of nitrogen for plant growth, fewer reports are available to understand the application and biological role of N 2 fixing bacteria to improve N 2 nutrition in the sugarcane plant. Results In this study, a total of 350 different bacterial strains were isolated from rhizospheric soil samples of the sugarcane plants. Out of these, 22 isolates were selected based on plant growth promotion traits, biocontrol, and nitrogenase activity. The presence and activity of the nifH gene and the ability of nitrogen-fixation proved that all 22 selected strains have the ability to fix nitrogen. These strains were used to perform 16S rRNA and rpoB genes for their identification. The resulted amplicons were sequenced and phylogenetic analysis was constructed. Among the screened strains for nitrogen fixation, CY5 ( Bacillus megaterium ) and CA1 ( Bacillus mycoides ) were the most prominent. These two strains were examined for functional diversity using Biolog phenotyping, which confirmed the consumption of diverse carbon and nitrogen sources and tolerance to low pH and osmotic stress. The inoculated bacterial strains colonized the sugarcane rhizosphere successfully and were mostly located...