以编码HarpinXoo 的hrf1转基因水稻NJH12的cDNA为模板，克隆到了DUF500的保守功能区。序列分析表明，OsDUF500是DUF500家族成员，功能未知。构建OsDUF500的沉默载体，用土壤根癌农杆菌介导的方法转化粳稻 R109，用Hpt抗生素做抗性筛选，获得9个再生株系。经分子鉴定，8个为沉默株系（ABD2~9）。与野生型相比， ABD株系株高变矮，叶片变短，出现白色空秕谷。白叶枯病抗性鉴定结果表明，OsDUF500沉默株系对水稻白叶枯病的抗性存在差异，病斑长度比野生型明显缩短，病斑面积均在30%以下，株系ABD3和ABD5病斑面积分别为12.3%和15.7%，显示出较好的抗性。推测在稻瘟病抗性中上调表达基因OsDUF500对水稻白叶枯病抗性起负调控作用。
Conserved functional region of DUF500 was cloned by PCR from cDNA of expression HarpinXoo (hrf1) transgenic rice NJH12. OsDUF500 encodes an unknown function member of DUF500 family. Calli from mature embryos of rice cultivar R109 were transformed by Agrobacterium tumefaciens strain EHA105/ABD::pVec8. There were eight OsDUF500 transgenic lines from nine hygromycin resistant lines by PCR analysis. Compared with the wild type, the downexpressed lines ABD are characterized by reduced plant height, shortened leaf and white blighted grain. Disease assays of transgenic rice plants infected by Xanthomonas oryzae pv. oryzae (PXO99) indicated that different transgenic lines had different resistance to rice leaf blight. Lesion length of the downexpression lines reduced significantly and lesion area all bellowed 30%. Lesion areas of the ABD3 and ABD5 were 12.3% and 15.7%, respectively. Thus, we predicted OsDUF500gene, which was upregulated in rice blast, maybe was a negative regulator on bacterial blight resistance.
\[1\]Swings J, van den Mooter M, Vauterin L, et al. Reclassification of causal agents of bacterial blight( Xanthomona campestris pv. oryzae) and bacterial leaf streak(Xanthomona campestris pv. oryzicola) of rice as pathovars of Xanthomona pv. oryzae. Int J Syst Bacteriol, 1990, 40: 309311.
\[2\]陈利锋,徐敬友.农业植物病理学.3版.北京:中国农业出版社,2007.
\[3\]Shao M, Wang J S, Dean B A,et al. Expression of a harpinencoding gene in rice confers durable nonspecific resistance to Magnaporthe grisea. Plant Biotechnol J,2008,6: 7381.
\[4\]邵敏,肖姗姗,李林等. 转hrf1基因水稻对稻瘟病多小种非专化的稳定抗性.中国水稻科学, 2008,22 (5):459464
\[5\]Huang J, Zhi M, Hai L, et al. Agrobacterium tumefaciensmediated transformation of rice with the spider insecticidal gene conferring resistance to leaffolder and striped stem borer. Cell Res, 2001, 11(2):149155.
\[6\]顾红雅, 瞿礼佳, 明小天, 等. 植物基因与分子操作.北京: 北京大学出版社, 1995.
\[7\]方中达.植病研究方法.3版.北京: 中国农业出版社, 1996.
\[8\]Leevers S J, Vanhaesebroeck B, Waterfield M D. Signalling through phosphoinositide 3kinases: The lipids take centre stage. Curr Opin Cell Biol,1999, 11(2): 219225.
\[9\]amaj J, Read N D, Volkmann D, et al The endocytic network in plants. Trends Cell Biol，2005，15(8): 425433.
\[10\]Martinoia E, Maeshima M, Neuhaus H E. Vacuolar transporters and their essential role in plant metabolism. J Exp Bot, 2007, 58(1): 83102.
