Analysis of host genes that expression was regulated by the signal molecules produced by phytopathogen

豌豆枯萎病病原菌松孢球腔菌（Mycosphaerella pinodes）在萌发液中分泌两种信号分子：激发子和抑制子。激发子在植物上非特异性地诱导防御反应，而抑制子仅在寄主植物上否定诱导的防御反应。本研究以豌豆上胚轴为材料，首先构建了诱导子诱导的polyA + RNA的cDNA文库，然后利用差异筛选技术，对诱导子诱导的豌豆上胚轴的抗性基因进行了初步筛选，获得了诱导子诱导的豌豆上胚轴的polyA + RNA cDNA文库。通过差异筛选，我们分离出90个cDNA克隆作为激发子响应基因的候选者。这些克隆的测序分析显示如下。1)M. pinodes激发子可能诱导富含羟脯氨酸的糖蛋白和过氧化物酶基因的表达，以增强植物细胞壁。2)多聚半乳糖的推定cDNA ...更多信息 acturonase inhibiting protein和endochitinase的表达表明，这些基因可能是有效的不兼容的相互作用。3)多胺生物合成酶cDNA克隆的分离表明多胺在防御反应中的重要性。4)一个编码新型Dof型锌指转录因子的cDNA克隆特异性地结合许多防御相关基因启动子区的AAAG序列。这些结果表明，该蛋白通过激发子介导的许多防御反应相关基因的激活，在调控复杂的转录调控网络中发挥重要作用。另一方面，作为抑制反应基因，我们分离到了编码早期拟南芥素同源物、细胞壁降解酶和茉莉酸生物合成酶的cDNA克隆。特别是，茉莉酸生物合成酶的相应的mRNA特异性诱导接种亲和病原体在豌豆叶片。对这些感病特异基因的研究可能揭示亲和互作的形成机制。少

Pea blight pathogen, Mycosphaerella pinodes secrets two kinds of signal molecules, elicitors and suppressors in a germination fluid. Elicitors induce defense response non-specifically on plants and suppressors negate the induced defense response on only host plant. In this study, we have promoted to isolate cDNA clones that are induced by elicitor-treatment to totally understand the defense response and by suppressor-treatment to characterize the mechanisms for the establishment of the compatibility by differential screenings.As elicitor-inducible genes, we have first constructed a cDNA library from polyA+RNA prepared from elicitor-treated pea epicotyls for 5hr. By the differential screening, we have isolated 90 cDNA clones as candidates for elicitor-responsive genes. Sequencing analysis of these clones revealed as follows. 1) M. pinodes elicitor might induce gene expressions of hydroxyproline-rich glycoprotein and peroxidase to strengthen plant cell wall. 2) Putative cDNAs for polygal … More acturonase inhibiting protein and endochitinase demonstrates that these genes might be effective in incompatible interactions. 3) Isolation of many cDNA clones encoding the enzymes for polyamine biosynthesis indicates the importance of polyamine in defense response. 4) A cDNA clone encoding novel Dof type zinc-finger transcription factor binds specially to AAAG sequence present in the promoter region of many defense-related genes. These results indicate that the significance of this protein in the regulation of complex network of transcriptional regulation by the elicitor-mediated activation of a number of defense response-related genes.On the other hands, as suppressor-responsive genes, cDNA clones encoding homologs of early nodulin, cell wall degrading enzymes and biosynthetic enzyme for jasmonic acid were isolated. Particularly, corresponding mRNA to jasmonic acid biosynthetic enzyme was specifically induced by the inoculation of compatible pathogen in pea leaves. The investigation of these susceptible specific genes might reveal the mechanism of the establishment of compatible interactions. Less