Microbial Volatiles Mvocs Induced Defense Response Against Pathogens Of Rice And Tomato

Abstract

Plant diseases are critical biotic stress that severely affects plant growth and newlinedevelopment. The biological control agents (BCA) associated with plants are well known newlineto help in disease management and enhance plant health. Among them, the endophytic newlinemicroorganisms can support in reducing biotic stress by inducing defense termed as newlinemicrobe-induced defense priming. The mechanisms are by the production of enzymes, newlinemetabolites, and volatiles to manage the plant disease directly or by inducing defense and newlineplant growth to protect the plant indirectly. With this background, the present study aimed newlineto evaluate the microbial volatile organic compounds (mVOCs) produced by the newlineendophytic microorganisms of rice and tomato to induce plant growth and defense newlineresponse in plants. newlineRice endophytic fungus, Trichoderma longibrachiatum EF5, and tomato newlineendophytic yeast Candida tropicalis TY1 and bacterium Bacillus pumilus TEB10 were newlineisolated and screened for their antimicrobial activity against major pathogens of rice, and newlinetomato and soil-borne pathogens as well. These endophytes possessed plant growth- newlinepromoting attributes (Zn and P solubilization), hydrolytic enzymes (catalase, cellulase, and newlinex newlineprotease), and antagonistic (siderophore and HCN) activities. Further, these endophytic newlinemicroorganisms significantly reduced the pathogen growth through volatile mediated newlineinhibition. newlineThe variation in the VOCs and soluble metabolites mediated inhibition were newlinedocumented by profiling them in GC-MS-ATD from their axenic culture and during newlineinteraction. A vast difference in the VOCs and soluble metabolites were recorded during newlinethe interaction of antagonist and pathogen while sharing the same growing media. newlineMetabolites produced by antagonist or pathogen in their axenic culture was further newlineincreased or decreased in their intensities or some of them are not present, and also some newlinenew compounds were present during the interaction. T. longibrachiatum EF5 produced newlinelongifolene, cedrane, caryophyllene, 2-methyl-1-butanol, farnesene, dimethyl trisulfide, newlineb