title: Some tryptophan pathways in the phytopathogen Xanthomonas oryzae pv. oryzae.
abstract: Xanthomonas oryzae pv. oryzae, the causal organism of bacterial blight of rice which produces leaf blight as well as kresek (wilt) symptoms in plants were tested for indole, auxin production in culture supplemented with L-tryptophan. On the basis of indoleacetic acid (IAA) production the isolates were grouped into IAA-positive and IAA-negative. Out of 17 isolates, 11 were IAA-positive while 6 were IAA-negative. The isolates metabolized tryptophan through two different routes and the isolates vary in the pathway of tryptophan utilization. The IAA-positive isolates converted tryptophan to IAA as the end product, whereas the IAA-negative isolates formed anthranilate as an intermediate metabolite and finally produced pyrocatechol via the kynurenine pathway. Quantification of tryptophan metabolism revealed that the maximum production of IAA and pyrocatechol in culture occurred during 2-d incubation at 30 +/- 2 degrees C.
authors.affiliation: Laboratory of Molecular Plant Pathology, Central Rice Research Institute, Cuttack, Orissa, 753 006 India.
authors.forename: M M
authors.initials: MM
authors.lastname: Ansari
authors.forename: R
authors.initials: R
authors.lastname: Sridhar
mesh_terms: D002396:Catechols / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D007210:Indoleacetic Acids / Q000378:metabolism; D007737:Kynurenine / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D014364:Tryptophan / Q000378:metabolism*; D014974:Xanthomonas / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity; D062367:ortho-Aminobenzoates / Q000378:metabolism
chemical_list: D002396:Catechols; D007210:Indoleacetic Acids; D062367:ortho-Aminobenzoates; C031385:anthranilic acid; D007737:Kynurenine; C030737:indoleacetic acid; D014364:Tryptophan; C034221:catechol