Inhibitory action of mVOCs from Shewanella algae Sg8 against phytopathogenic fungi and transcriptional elicitation of PR genes in tomato

Abstract

Abstract The analysis of Microbial volatile organic compounds (mVOCs) is an emerging research field with huge impact in the fields of medical and agricultural biotechnology, mVOCs are being considered as imminent eco-friendly alternatives to chemical pesticides and fertilizers in sustainable agriculture. In this study, we characterized the effect of volatiles emitted from Shewanella algae (Sg8) isolated from a marine ecosystem in promoting plant growth, in controlling the activity of Fusarium oxysporum and its antagonistic activity against other phytopathogenic fungus. Sg8 inhibited the growth of four other agronomically important foliar and soil plant pathogens: Botrytis cinerea, Colletotrichum gloeosporioides, Magnoporthae oryzae and Macrophomina sp. The effect of mVOCs produced by the bacterium Sg8, on plant growth were investigated on tomato plants under in vivo conditions. The VOCs emitted from Sg8 up regulated the Thaumatin-like antifungal (PR-5) gene (9-fold) and Glutamine synthetase (GS) gene (0.96-fold) in tomato plants. Sg8 effectively inhibited the growth of F. oxysporum and possessed plant growth promoting (PGP) activity. Our results show that Sg8 generates bioactive volatiles that induces the regulation of Pathogenesis related (PR) genes, and stimulates the growth of the plants and also suppresses the growth of other agriculturally important foliar and soil phyto-pathogenic fungus.