title: Transcriptional characteristics of Xa21-mediated defense responses in rice.
abstract: Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is the most destructive bacterial disease of rice. The cloned rice gene Xa21 confers resistance to a broad spectrum of Xoo races. To identify genes involved in Xa21-mediated immunity, a whole-genome oligonucleotide microarray of rice was used to profile the expression of rice genes between incompatible interactions and mock treatments at 0, 4, 8, 24, 72 and 120 h post inoculation (hpi) or between incompatible and compatible interactions at 4 hpi, respectively. A total of 441 differentially expressed genes, designated as XDGs (Xa21 mediated differentially expressed genes), were identified. Based on their functional annotations, the XDGs were assigned to 14 categories, including defense-related, signaling, transcriptional regulators. Most of the defense-related genes belonged to the pathogenesis-related gene family, which was induced dramatically at 72 and 120 hpi. Interestingly, most signaling and transcriptional regulator genes were downregulated at 4 and 8 hpi, suggesting that negative regulation of cellular signaling may play a role in the Xa21-mediated defense response. Comparison of expression profiles between Xa21- and other R gene-mediated defense systems revealed interesting common responses. Representative XDGs with supporting evidences were also discussed.
authors.affiliation: Institute of Genetics and Developmental Biology, the Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gan
authors.forename: Hui
authors.initials: H
authors.lastname: Bai
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Zhao
authors.forename: Yong
authors.initials: Y
authors.lastname: Tao
authors.forename: Haipan
authors.initials: H
authors.lastname: Zeng
authors.forename: Yuning
authors.initials: Y
authors.lastname: Han
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Song
authors.forename: Lihuang
authors.initials: L
authors.lastname: Zhu
authors.forename: Guozhen
authors.initials: G
authors.lastname: Liu
mesh_terms: D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D012275:Oryza / Q000235:genetics* / Q000276:immunology / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D015203:Reproducibility of Results; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014974:Xanthomonas / Q000502:physiology*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors