Beneficial Linkages of Endophytic Burkholderia anthina MYSP113 Towards Sugarcane Growth Promotion

Abstract

Microbial agents are the best alternative to the chemical fertilizers that promote the plant growth in an eco-friendly manner. This study was intended to characterize Burkholderia anthina strain MYSP113 and to evaluate its mechanisms linked to sugarcane growth promotion. The morphological, biochemical, and molecular characterization (gyrB and recA) results identified the bacteria as B. anthina. To determine the plant bacterial association, MYSP113 strain was tagged with a plasmid-bear green fluorescent protein (gfp) gene, and the tagged strain was inoculated to the sugarcane (variety GXB-9), and bacterial colonization analyzed by confocal laser fluorescence microscopy. The results revealed that strain MYSP113 had root-colonizing abilities, and colonization was detected at the root and leaves maturation zones. Bacteria entered the roots via cracks at the surfacing site of the roots and disrupted epidermis. Bacterial cells were observed in the substomatal chambers of leaves. Furthermore, to evaluate the mechanisms related to sugarcane growth promotion and bacterial competence in soil and plant, greenhouse experiment performed, and bacterial competence, plant growth parameters, and phytoenzymes, and hormones were assessed with or without MYSP113. We examined bacterial competence in soil and plant via qPCR and direct plant count at 45 and 90 DAI, and results recommended that strain MYSP113 has the ability to colonize in sugarcane rhizosphere and in the aerial part of the plant. Furthermore, strain MYSP113 significantly induced the plant fresh weight, dry weight, and chlorophyll content of sugarcane seedlings at 45 and 90 days after inoculation. Additionally, strain MYSP113 triggered chitinase, cellulose, indole acetic acid, and abscisic acid production in the plant roots and aerial parts, and these results signifying that bacterial inoculation modulates the plant metabolism and boost the health. The present study concluded that strain MYSP113 has beneficial linkages with the sugarcane plant, and it would be utilized as a bioinoculant in future.