6个小麦抗叶锈病近等基因系的cDNA-AFLP差异表达分析

Analysis of differential expression of six wheat leaf rust resistance near-isogenic lines

应用cDNA-AFLP技术对小麦抗叶锈病近等基因系TcLr9、TcLr15、TcLr19、TcLr25、TcLr38、TcLr45和感病亲本Thatcher间的表达差异进行分析,共选用226对引物组合对其进行筛选,检测出7 554条条带,平均每对引物可获得33条扩增条带。筛选出68对引物能够在小麦抗叶锈病近等基因系TcLr9、TcLr15、TcLr19、TcLr25、TcLr38、TcLr45和感病亲本Thatcher之间扩增出特异表达条带,特异表达检出率为30.1%。68对引物共扩增出84条特异表达条带,并根据基因表达与否及表达量划分为9种不同的特异表达类型(I^IX)。其中,I、V和VII型特异表达类型为组成型表达,共49条;II、IV、VI和VIII型特异表达类型表达上调,共21条;III和IX型特异表达类型表达下调,共14条。有5种特异表达类型(IV、V、VI、VII、VIII型)可能与小麦的抗病反应相关,并且这5种特异表达类型又分为两类亚型,第一类亚型是小麦抗叶锈病近等基因系与小麦叶锈菌互作时特异表达(I V型)或者表达量明显增加(VI、VIII型),为诱导性特异表达类型;第二类亚型为组成型特异表达类型(V、VII型)。

The cDNA- AFLP technique was employed to analyse differential expression of wheat leaf rust resistance near- isogenic lines TcLr9, TcLrlS, TcLr19, TcLr25, TcLr38, TcLr45 and Thatcher. 226 primer pairs were used to screen for differential expression analysis. As a result, 7 554 bands were detected totally, and 33 bands were amplified by each primer pair. 68 primer pairs can be amplified into differential expression bands among TcLr9, TcLrlS, TcLrl9, TcLr25, TcLr38, TcLr45 and Thatcher, and the detection rate of differential expression bands was at 30.1%. 84 differential expression bands amplified by 68 primer pairs were classified into 9 types of differential expression （Ⅰ～Ⅸ）. Types Ⅰ,Ⅴ and Ⅶ were constitutive expression, in all 49 bands; Types Ⅱ,Ⅳ,Ⅵ and VIII were upregulated, in all 21 bands; Types Ⅲ and IX were downregulated, in all 14 bands. Fives of nine types （Ⅳ, Ⅴ,Ⅵ,Ⅶ, Ⅷ） were probably linked with disease resistance, and the five types were classified into two subtypes again. The first subtype was induced expression （Ⅳ, Ⅵ,Ⅷ）, and the second was constitutive expression （Ⅴ,Ⅶ）.