番茄myb基因片段的克隆及在过敏性反应时的表达

 以烟草myb1 中MYB 保守区域编码序列的两个相对特异性序列为引物, 以表现过敏性反应(hypersensitive response , HR) 的番茄苗中提取的RNA 为模板, 通过RT- PCR 获取长度为215 bp 的myb 基因片段LeMYB1 和LeMYB2 (GenBank 核酸序列数据库登录号: AY131230 和AY131231) 。两者只有第63 位碱基不同, 前者序列为A , 而后者为G。Northern 杂交分析表明, LeMYB 相关基因表达时序与番茄苗HR 的产生和发展呈密切正相关, 因而可能在Cf-9 决定的HR 和抗病性产生中起调节作用。

Cloning of Tomato myb Gene Fragments and Expression upon Development of Hypersensitive Response

Two 215 bp myb gene fragments,LeMYB1 and LeMYB2 w it h GenBank accession No.AY131230 and AY131231 respectively,were cloned through RT -PCR.The pri mers were designed in accordance with tobacco myb1 at the DNA-binding domai n conserved in MYB,and the template was the RNA isolated from tomato seedlings showing hypersensitive responses(HR).Only nucleotide 63 was different between the two fragments,of which LeMYB1 was A and LeMYB2 was G.Three nucleo tides within the primers for cloning of LeMYB1 were different between LeMYB1 and counterpart of THM18,whereas 90 7% nucleotide sequence of LeMYB1 was identical to corresponding parts of tobacco myb1 .Northern assay revealed that expression of LeMYB1-related genes were ind uced upon occurrence of hyperse nsitive necrosis in tomato seedlings and enhanced henceforth.Their coincident ex pression with HR development in tomato indicated that LeMYB1-related genes might be involved in regulation of HR and disease resistance conferred by tomato fungal resistance gene Cf-9.