The defense-responsive genes showing enhanced and repressed expression after pathogen infection ...
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L.) ZHOU Bin PENG Kaiman CHU Zhaohui WANG Shiping ZHANG Qifa National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China Science in China Series C-Life Sciences 2002 Vol.45 No. 5 pp.449-467 Code:01YC0302 DOI:10.1360/02yc9050 Abstract:Despite large numbers of studies about defense response, processes involved in the resistance of plants to incompatible pathogens are still largely uncharacterized. The objective of this study was to identify genes involved in defense response by cDNA array analysis and to gain knowledge about the functions of the genes involved in defense response. Approximately 20000 rice cDNA clones were arrayed on nylon filters. RNA samples isolated from different rice lines after infection with incompatible strains or isolates of Xanthomonas oryzae pv. oryzae or Pyriculariagrisea , respectively, were used to synthesize cDNA as probes for screening the cDNA arrays. A total of 100 differentially expressed unique sequences were identified from 5 pathogen-host combinations. Fifty-three sequences were detected as showing enhanced expression and 47 sequences were detected as showing repressed expression after pathogen infection. Sequence analysis revealed that most of the 100 sequences had various degrees of homology with genes in databases which encode or putatively encode transcription regulating proteins, translation regulating proteins, transport proteins, kinases, metabolic enzymes, and proteins involved in other functions. Most of the genes have not been previously reported as being involved in the disease resistance response in rice. The results from cDNA arrays, reverse transcription-polymerase chain reaction, and RNA gel blot analysis suggest that activation or repression of most of these genes might occur commonly in the defense response. Keywords:bacterial blight, blast, defense-related genes, cDNA arrays.