Whole genome sequencing and identification of host-interactive genes in the rice endophytic Leifsonia sp. ku-ls

Abstract

Leifsonia sp. ku-ls is an endophytic bacterial strain colonizing in high numbers the stem and leaf of the high-yielding and widely grown indica rice cultivar RP Bio-226. Whole genome sequencing of this strain using Illumina Hiseq-2500 system resulted in generation of 10,103,994 paired-end reads of 150 nucleotides length. De novo assembly of the reads with A5MySeq resulted in 51 scaffolds. Kmer analysis with KAT estimated the genome size as 3.83 Mbp with 70% GC content. Annotation of the genome resulted in identification of 3930 protein-coding genes, 45 tRNA genes, and 3 rRNA genes. Detailed analysis of the genes predicted resulted in identification of host beneficial genes which include genes associated with hormone production, nitrogen metabolism, and stress response. There is an elaborate defense against oxidative stress present in this bacterium which also can mitigate plant oxidative stress resulting from disease/abiotic stress. Comparison of this endophytic bacterial genome with non-endophytic Leifsonia sp. showed presence of additional genes, increase in copy number of some of the genes and regulators. Many genes with eukaryotic-like domains have also been identified in this bacterium.

Keywords: Endophytic bacteria; Eukaryotic-like proteins; Genome; Leifsonia; Rice.