Jia Y, Martin G B
Department of Agronomy, Purdue University, West Lafayette, IN 47907-1150, USA.
Plant Mol Biol. 1999 Jun;40(3):455-65. doi: 10.1023/a:1006213324555.
In the yeast two-hybrid system, the Pto kinase interacts with three putative transcription factors Pti4, Pti5 and Pti6. The Pti4/5/6 proteins contain a DNA binding domain that recognizes and binds a DNA sequence (5'-AGCCGCC3'; the 'PR box') present in the promoter region of a large number of genes encoding 'pathogenesis-related' (PR) proteins. We have now investigated the pathogen-induced expression of PR box-containing genes in tomato. We isolated a tomato osmotin gene that contains two PR boxes in its promoter region and demonstrated that the abundance of the osmotin transcript rapidly increases during an incompatible interaction involving Pro-containing tomato plants and the bacterial pathogen Pseudomonas syringae pv. tomato expressing the avrPto gene. In addition, we found that transcripts of two other tomato PR genes (encoding endochitinase and beta-1,3-glucanase B) and at least one ACC oxidase gene, all of which contain PR boxes in their promoter regions, rapidly accumulate in the incompatible interaction. These data support the hypothesis that the tomato Pto kinase regulates the expression of certain defense genes in tomato by interaction with transcription factors that bind the PR box.
在酵母双杂交系统中，Pto激酶与三种假定的转录因子Pti4、Pti5和Pti6相互作用。Pti4/5/6蛋白含有一个DNA结合结构域，该结构域可识别并结合大量编码“病程相关”（PR）蛋白的基因启动子区域中存在的DNA序列（5'-AGCCGCC3'；“PR框”）。我们现在研究了番茄中含PR框基因的病原体诱导表达。我们分离出一个番茄渗透素基因，其启动子区域含有两个PR框，并证明在涉及含Pro的番茄植株与表达avrPto基因的细菌病原体丁香假单胞菌番茄致病变种的不亲和互作过程中，渗透素转录本的丰度迅速增加。此外，我们发现另外两个番茄PR基因（编码内切几丁质酶和β-1,3-葡聚糖酶B）以及至少一个ACC氧化酶基因的转录本，它们的启动子区域都含有PR框，在不亲和互作中迅速积累。这些数据支持了这样的假说，即番茄Pto激酶通过与结合PR框的转录因子相互作用来调节番茄中某些防御基因的表达。
