水稻抗稻瘟病近等基因系的cDNA微阵列分析

Analysis of Gene Expression Profiles During Host-Magnaporthe grisea Interactions in a Pair of Near Isogenic Lines of Rice

应用cDNA微阵列对来源于中 15 6 /谷梅 2号重组自交系的水稻抗稻瘟病近等基因系G2 0 5和G71的稻瘟病菌胁迫基因表达谱进行了分析 ,发现有 3个cDNA克隆的表达仅在抗病基因系G2 0 5接种病原菌 12h后受到诱导 ,其中两个为功能已知基因 ,另一个为功能未知的新基因。另有 35个差异表达克隆在两个近等基因系中均检测到 ,其中 17个克隆的表达在G2 0 5和G71均受到病原菌的诱导 ,另外 18个克隆的表达则在G2 0 5和G71均受到病原菌的抑制。序列分析表明 ,这些稻瘟病菌应答基因分别与防卫反应、信号传递、逆境胁迫和光合作用及糖代谢等功能相关 ,为植物抗病机制提供了相关信息。另外 ,Northern还证实了编码富含甘氨酸蛋白基因 (GlycinerichproteinGrp)的表达受稻瘟病病原菌的诱导 ,是一个稻瘟病诱导相关基因。

A pair of near isogenic lines G205 and G71 were selected from recombinant inbred lines (RIL) of Zhong156×Gumei2. On the resistance locus Pi 25( t ), G205 had the resistant allele that was from Gumei 2 while G71 had the susceptible allele that was from Zhong156. For the genetic background, different alleles were detected on only 24 loci out of the 672 RFLP or SSLP loci surveyed. The expression profiles of G205 and G71 in response to Magnaporthe grisea were investigated using cDNA microarrary containing 2200 Expression Sequence Tags (ESTs). The leaves were inoculated with the pathogen for 12 hours at 4 leaf stage and 998 genes were identified in total. Three genes were up regulated significantly by the fungus in G205 only. The functions of two genes were known but that of the third gene were unknown. The two genes encoded casein kinase Ⅱ alpha subunit and retrotransponson TOS17 insertion element respectively. Other thirty five genes had similar expression patterns between NILs. Among them, 17 genes were up regulated while 18 genes were down regulated by the inoculation. The functions of 33 out of the 35 genes were known. BLAST analysis showed that all thirty five. BLAST analysis showed that all thirty five genes with known functions were relative to defense reactions, signal transduction, stress response, photosynthesis and sugar metabolism. Northern blot confirmed that four of five differentially displayed genes randomly selected had the same expression patterns as those detected in cDNA microarray. Two of them were up regulated genes encoding casein kinase Ⅱ alpha subunit and glycine rich protein ( Grp ), and the other two down regulated genes encoding nitrilase associated protein and 18S small subnit ribosomal RNA gene respectively. Northern blot also revealed that the expression of Grp was consistently up regulated from 0 to 36h after the inoculation of the fungus. These results showed that cDNA microarray was a useful tool to study the molecular mechanisms of disease resistance in plants.