AUTHOR=Singh Pratiksha , Singh Rajesh Kumar , Guo Dao-Jun , Sharma Anjney , Singh Ram Nageena , Li Dong-Ping , Malviya Mukesh K. , Song Xiu-Peng , Lakshmanan Prakash , Yang Li-Tao , Li Yang-Rui 

TITLE=Whole Genome Analysis of Sugarcane Root-Associated Endophyte Pseudomonas aeruginosa B18—A Plant Growth-Promoting Bacterium With Antagonistic Potential Against Sporisorium scitamineum

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.628376

DOI=10.3389/fmicb.2021.628376

ISSN=1664-302X

ABSTRACT=<p>Sugarcane smut is a significant fungal disease that causes a major loss in sugar yield and quality. In this study, we isolated an endophytic strain B18 from a sugarcane root, which showed plant growth-promotion, hydrolytic enzyme production, antifungal activity against sugarcane pathogens (<italic>Sporisorium scitamineum, Ceratocystis paradoxa, Fusarium verticillioides</italic>), and the presence of <italic>nifH</italic>, <italic>acdS</italic>, and antibiotic genes (<italic>hcn, prn</italic>, and <italic>phCA</italic>) under <italic>in vitro</italic> conditions. BIOLOG<sup>(R)</sup> phenotypic profiling of B18 established its ability to use various carbon and nitrogen sources and tolerate a range of pH and osmotic and temperature stresses. Whole-genome analysis of B18, identified as <italic>Pseudomonas aeruginosa</italic>, showed that it consists of a single circular chromosome of 6,490,014 bp with 66.33% GC content. Genome annotation has identified 5,919 protein-coding genes, and 65 tRNA, and 12 rRNA genes. The <italic>P. aeruginosa</italic> B18 genome encodes genes related to ethylene, nitrogen (<italic>nifU</italic>, <italic>norBCDERQ</italic>, <italic>gltBDPS</italic>, and <italic>aatJMPQ</italic>), and phosphate (<italic>pstABCS</italic> and <italic>phoBDHRU</italic>) metabolism and produce indole-3-acetic acid and siderophores. This also includes genes encoding hydrolases and oxidoreductases, those associated with biocontrol mechanisms (<italic>hcnABC</italic>, <italic>phzA_B</italic>, <italic>phzDEFGMS</italic>, and <italic>pchA</italic>), colonization (<italic>minCDE</italic> and <italic>lysC</italic>), and biofilm formation (<italic>efp</italic>, <italic>hfq</italic>, <italic>flgBCDEFGHI</italic>, and <italic>motAB</italic>), and those associated with metabolism of secondary metabolites. Collectively, these results suggest a role for <italic>P. aeruginosa</italic> B18 in plant growth enhancement and biocontrol mechanisms. The <italic>P. aeruginosa</italic> B18 strain was found to be an efficient colonizer in sugarcane; it can improve growth through modulation of plant hormone production and enhanced host-plant resistance to smut pathogen <italic>S. scitamineum</italic> in a smut-susceptible sugarcane variety (Yacheng71-374). These biocontrol and plant growth promotion properties of <italic>P. aeruginosa</italic> B18 area are discussed in this report.</p>