Phylogenetic analysis, molecular characterization and virulence profiling based on toxoflavin gene of an Indian BG1 strain of causing panicle blight of rice.

UNLABELLED

Bacterial panicle blight (BPB) caused by (BG) has become significantly more prevalent in the rice-growing regions of North India. Based on virulence screening and in vitro quantification of toxoflavin, the BG strains were classified as hyper- (BG1 and BG3), moderate- (BG2, BG4, BG6, BG8, and BG9), and hypo- (BG5, BG7, and BG10) virulent. Plant inoculation assays with cell-free culture filtrate revealed strains with higher toxoflavin-producing ability had higher virulence. Based on 16S rRNA sequence, 6 isolates from Uttar Pradesh were grouped in clad C1; whereas, clad C2 exhibited 4 isolates, two each from Delhi and Uttar Pradesh. Strain BG1 being the most virulent Indian strain from Uttar Pradesh was further profiled for 11 genes. We found all the 11 genes present in strain BG1. In cluster, all genes showed high similarity to BGR1 except , whereas in cluster , and shared maximum similarity to 336gr-1. genes of BG1 exhibited homology as well as divergence with . The domain prediction and protein association network analysis indicated the possible involvement of genes in the toxoflavin biosynthesis. As per our knowledge, this is the first report in India on characterization of genes cluster in . Altogether, our study unravels a reliable method for identifying and characterizing using genes and its relationship with disease production.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-023-03660-6.