Insights in to the genome sequence of an endophytic Bacillus amyloliquefaciens (TNOB22) from tea and its promising biocontrol activity against major diseases of tea

Abstract

Tea cultivation in South India is threatened by several foliar and root diseases. Use of fungicides for these diseases cause several health hazards to humans and develop fungicide resistance. In this context, the biological approaches by exploiting antagonistic bacteria especially Bacillus spp will play a vital role in managing the diseases and promote plant growth. Current study is focused on the isolation, identification, in vitro evaluation and whole genome sequencing of an efficient endophytic Bacillus amyloliquefaciens. The bacterial endophyte B. amyloliquefaciens (TNOB 22) significantly inhibited several pathogens causing tea diseases. The results of whole genome sequencing confirmed the isolate as B. amyloliquefacies with a genome size of 3.8 Mb with 46 % of GC content. The assembled genome consists 21 contigs with 3940 protein coding sequences (CDS); 59 transfer RNA (tRNA) genes and 2 ribosomal RNA (rRNA) genes. The genome has speciality gene clusters viz., aantibiotic resistance genes (53), drug target genes (48), transporter (191) and virulence factor genes (5). The isolate also has gene coding for several antifungal metabolites viz., bacillaene, bacillomycin D, bacilysin, macrolactin H, macrolactin B, macrolactin E, macrolactin 1C, mycosubtilin, paenibactin, paenilarvin A, paenilarvin B, paenilarvin C, fengycin, iturin, surfactin and plantazolicin. The pan genome analysis revealed the presence of increasing trend of pan genome represents the isolate could adopt to various ecological niches. These findings explored the biocontrol potential of B. amyloliquefaciens (TNOB 22) against major pathogens causing diseases on tea.