Study of the defense response and gene regulation for pathogen attack

本研究的目的是阐明参与植物主动防御反应的寄主-病原菌特异性基因的信号转导和调控机制。我们对豌豆中编码PAL和CHS的植物主动防御基因的激活和失活所涉及的分子基础进行了深入的研究，特别是对豌豆病原菌Mycosphaerella pinodes产生的激发子和抑制子的作用进行了研究。1.对PAL基因的一个成员(PSPAL1)和豌豆的一个小的多基因家族的人工重建表明，在真菌激发子处理的功能丧失和功能获得的实验中，盒2和盒4的保守序列基序在介导的激活中起着非常重要的作用。2.携带PSPAL1启动子-GUS-NOS终止子嵌合体的转基因烟草的产生(除了这些构建物连接到GUS报告基因而不是CAT基因外，与1中描述的相同类型的嵌合基因)表明Boxes1、2和4是应答病原菌攻击的先决条件顺式元件。这些元件在真菌激发子处理所介导的激活反应中也是重要的。PSPAL1(翻译融合型)启动子的-1,394至+140或至+115具有组织特异性表达，特别是在根、茎下部的分生组织中，以及在花器官组织中高表达，这些组织中有粉红色色素的沉积和木质素的强烈表达。-1,394到+5或to-27的嵌合融合只有很少的GUS表达，这表明外显子序列在转基因烟草的表达中是重要的。

The object of this research is to elucidate the mechanisms of signal transduction and control of the genes involved in plant active defense responses conferring host-pathogen specificity. We intensively characterized the molecular basis involved in the activation and deactivation of plant active defense genes encoding PAL and CHS in pea, particularly focused on the study of the effects of elicitor and suppressor produced by a pea pathogen, Mycosphaerella pinodes. Details of the current status of the studies are,1.Artificial reconstruction of a members of PAL gene (PSPAL1) and in a small multigene family of pea demonstrated that the conserved sequence motifs of Box 2 and Box 4 were very important in the activation mediated by the treatment with fungal elicitor by so called Loss of Function and Gain of Function Experiments. However, Box 1 functions in a concerted manner with Box 2 and Box 4, probably forming a transcriptional activation complex.2.Generation of transgenic tobacco carrying the chimeric PSPAL1 promoter-GUS-Nos terminator construct (same types of the chimeric gene as described in 1 except these construct are connected to GUS reporter gene instead of CAT gene) demonstrated that Boxes1,2, and 4, are prerequisite cis-elements in response to the pathogen attack. These elements are also important in response to the activation mediated by the treatment with fungal elicitor. -1,394 to +140 or to +115 of PSPAL1 (translational fusion type) promoter contributed the tissue-specific expression, particularly in the merismatic tissues of roots, lower part of stems and very high expression in the tissues of flower organs where pink pigment is deposited and lignins are vigorously for med. Chimeric fusion of -1,394 to +5 or to -27 exhibited very little GUS expression, indicating that the exonic sequences are important in the expression if transgenic tobacco.