Genetic Loci of Plant Pathogenic IPO 2222 Expressed in Contact with Weed-Host Bittersweet Nightshade ( L.) Plants.

, belonging to the Soft Rot , are aggressive necrotrophs, exhibiting both a wide geographic distribution and a wide host range that includes many angiosperm orders, both dicot and monocot plants, cultivated under all climatic conditions. Little is known about the infection strategies employs to infect hosts other than potato ( L.). Our earlier study identified Tn5 mutants induced exclusively by the presence of the weed host . The current study assessed the identity and virulence contribution of the selected genes mutated by the Tn5 insertions and induced by the presence of . These genes encode proteins with functions linked to polyketide antibiotics and polysaccharide synthesis, membrane transport, stress response, and sugar and amino acid metabolism. Eight of these genes, encoding UvrY (GacA), tRNA guanosine transglycosylase Tgt, LPS-related WbeA, capsular biosynthesis protein VpsM, DltB alanine export protein, glycosyltransferase, putative transcription regulator YheO/PAS domain-containing protein, and a hypothetical protein, were required for virulence on plants. The implications of interaction with a weed host, , are discussed.