中国水稻科学

• 研究报告 • 上一篇    下一篇

中国水稻白叶枯病菌小种C8菌株无毒基因的分离及功能鉴别

纪志远1, #,杨 娟1, #,王寅鹏1,周 丹1,李玉蓉1,邹丽芳2,陈功友1, 2,*   

  1. 1南京农业大学 植物保护学院/农业部病虫监测与治理重点开放实验室, 江苏 南京 210095; 2上海交通大学 农业与生物学院,上海 200240; #共同第一作者; *通讯联系人, E-mail: gyouchen@njau.edu.cn
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2009-09-10 发布日期:2009-09-10

Identification of a Specific Avirulence Gene from a Chinese Race C8 of Xanthomonas oryzae pv. oryzae

JI Zhi-yuan1, #, YANG Juan1, #, WANG Yin-peng1, ZHOU Dan1, LI Yu-rong1, ZOU Li-fang2, CHEN Gong-you1, 2, *   

  1. 1 College of Plant Protection/Key Laboratory for Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; 2 College of Agriculture and Biology, Shanghai Jiaotong University, Shanghai 200240, China; # These authors contributed equally to this paper; *Corresponding author, E-mail: gyouchen@njau.edu.cn
  • Received:1900-01-01 Revised:1900-01-01 Online:2009-09-10 Published:2009-09-10

摘要: 白叶枯病菌与水稻间的互作符合基因对基因模式,不同小种中存在特异的avrBs3/pthA家族基因。对中国水稻白叶枯病菌小种C8菌株基因组DNA进行BamHⅠ酶切和Southern杂交,发现了其特有的约6.0 kb大小、含avrBs3/pthA家族基因的信号条带。经文库筛选、Southern杂交和限制性酶切分析,获得了C8小种avr/pthC8a基因。将该基因导入菲律宾小种6 的代表菌株PXO99A中,发现avr/pthC8a可使PXO99A丧失对水稻品种Asominori(携有成株期抗性基因Xa17)的毒性,暗示avr/pthC8a可能是与Xa17相应的无毒基因。序列分析发现,avr/pthC8a基因大小为3816 bp,编码1272个氨基酸,由102 bp编码的34个氨基酸重复单元在基因内的重复数为20.5个,其3′端的BamHⅠ酶切位点由GGATCC突变为AGATCC,其他特征均与avrBs3/pthA家族的成员相似,即C端存在1个亮氨酸拉链、3个核定位信号和1个酸性转录激活域。avr/pthC8a基因3′端的BamHⅠ酶切位点发生突变在avrBs3/pthA家族基因中鲜有报道。中国C8小种avr/pthC8a基因的发掘,为进一步了解水稻黄单胞菌毒性变异以及avrBs3/pthA家族基因的进化提供了理论依据。

关键词: 水稻, 白叶枯病菌, 无毒基因, 基因功能

Abstract: The interaction between Xanthomonas oryzae pv. oryzae (Xoo) and rice follows geneforgene model. A 6.0 kb particular fragment was identified from a Chinese race C8 strain of Xoo, through screening its genomic library by Southern blot with a highly conserved EcoRⅠBamHⅠ fragment of the avrBs3/pthA family as probe. This specific DNA contained an avirulence gene, namely avr/pthC8a, which transmitted the Philippine strain PXO99A from compatible into incompatible interactions with rice Asominori carrying R gene Xa17, suggesting that avr/pthC8a is possibly corresponding for Xa17 specificity. Sequence analysis showed that avr/pthC8a, 3819 bp in size, is a avrBs3/pthA family member, and the repeat number of the 102 bp repeat unit is 20.5. The structure of the gene is almost as same as those of the avrBs3/pthA family genes at 5′ and 3′terminals. The putative protein has a lucine zipper, three nucleotide location signals and an acid transcriptional activation domain at Cterminal. The novel is that the BamHⅠ site at 3′terminal of the gene is mutagenesis from GGATCC into AGATCC, which has not been reported so far. Thus, identification of avr/pthC8a of Chinese race C8 provides a fundamental understanding of virulence differentiation among different races of Xoo and coevolution of avrBs3/pthA genes with rice.

Key words: rice, Xathomonas oryzae pv. oryzae, avirulence gene, gene function