Molecular and Biochemical Basis of Plant Pathogen Interaction in Tomato Tolcv and Rice Rhizoctonia solani in Presence of Actinobacteria

Abstract

The success of bio-control in agriculture can be achieved when efficient newlinemicrobial agents are selected and characterized based on defined objectives. newlineActinobacteria is the largest phyla among the bacteria known for its extensive secondary newlinemetabolite production under stress. The advancement in microbiology through newlinemolecular biology techniques can be the gold standard to identify and classify the newlineefficient actinobacterial isolates. The current study is focused on isolation, in vitro newlinescreening, identification of antimicrobial genes (PKS1 and PKS2) to identify the newlineefficient actinobacterial isolate, qRT-PCR analysis to study the effect of actinobacterial newlineinoculation in presence and absence of sheath blight disease in rice and tomato leaf curl newlinevirus disease in tomato and metabolic profiling of secondary metabolites produced by newlineefficient actinobacterial isolate under stress. The soil samples collected from ecological newlineniches like forest tree rhizosphere, grass rhizosphere, forest litter soil and swampy area newlinesoil (water bodies) of Assam were used for isolation of actinobacteria from different soil newlinesamples was done using 4 different media components from 10-3 to 10-5 dilutions to newlineretrieve maximum number of isolates. Based on morphological characters the individual newlineisolates were picked and purified. The individual isolates were screened against five newlineplant pathogens (Rhizoctonia solani, Fusarium oxysporum, Sclerotium rolfsii, Rolstonia newlinesolanacearum and Xanthomonas oryzae). Eighty actinobacterial isolates were purified newlineand among them 16 isolates showed antagonistic effect on selected plant pathogens. The newlineisolate DBT64 was found to be potent against five pathogens based on in vitro studies. newlineBoth PKS1 and PKS2 genes were identified using degenerate primers in DBT64 and the newlineamplicon sequencing results depicted that DBT64 genes can encode protein products newlinewith anti-microbial activity. The LC-MS analysis identified antimicrobial metabolites newlinesuch as linoleic acid, coumaroyl tyramine, alkaloids, amino acids which were found to newlinehave