title: Rice Leaf Transcriptional Profiling Suggests a Functional Interplay Between Xanthomonas oryzae pv. oryzae Lipopolysaccharide and Extracellular Polysaccharide in Modulation of Defense Responses During Infection.
abstract: Treatment of rice leaves with isolated Xanthomonas oryzae pv. oryzae lipopolysaccharide (LPS) induces the production of callose deposits, reactive oxygen species, and enhanced resistance against subsequent bacterial infection. Expression profiling of X. oryzae pv. oryzae LPS-treated rice (Oryza sativa subsp. indica) leaves showed that genes involved in the biosynthetic pathways for lignins, phenylpropanoids, chorismate, phenylalanine, salicylic acid, and ethylene, as well as a number of pathogenesis-related proteins are up-regulated. Gene ontology categories like cell-wall organization, defense response, stress response, and protein phosphorylation/kinases were found to be upregulated, while genes involved in photosynthesis were down-regulated. Coinfiltration with xanthan gum, the xanthomonas extracellular polysaccharide (EPS), suppressed LPS-induced callose deposition. Gene expression analysis of rice leaves that are treated with an EPS-deficient mutant of X. oryzae pv. oryzae indicated that a number of defense-regulated functions are up-regulated during infection. These transcriptional responses are attenuated in rice leaves treated with an EPS-deficient mutant that is also deficient in the O-antigen component of LPS. Overall, these results suggest that the O-antigen component of X. oryzae pv. oryzae LPS induces rice defense responses during infection and that these are suppressed by bacterial EPS.
authors.affiliation: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
authors.forename: Anil Madhusoodana
authors.initials: AM
authors.lastname: Girija
authors.affiliation: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
authors.forename: Bipin Kumar
authors.initials: BK
authors.lastname: Kinathi
authors.affiliation: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
authors.forename: Mylavarapu B
authors.initials: MB
authors.lastname: Madhavi
authors.affiliation: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
authors.forename: Palaparthi
authors.initials: P
authors.lastname: Ramesh
authors.affiliation: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
authors.forename: Sridivya
authors.initials: S
authors.lastname: Vungarala
authors.affiliation: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
authors.forename: Hitendra Kumar
authors.initials: HK
authors.lastname: Patel
authors.affiliation: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
authors.forename: Ramesh V
authors.initials: RV
authors.lastname: Sonti
mesh_terms: D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology*; D012275:Oryza / Q000187:drug effects / Q000235:genetics* / Q000276:immunology; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics* / Q000276:immunology; D018517:Plant Roots / Q000187:drug effects / Q000276:immunology; D011134:Polysaccharides / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects; D014974:Xanthomonas / Q000378:metabolism* / Q000502:physiology
chemical_list: D008070:Lipopolysaccharides; D011134:Polysaccharides