Bisgrove S R, Simonich M T, Smith N M, Sattler A, Innes R W
Department of Biology, Indiana University, Bloomington 47405.
Plant Cell. 1994 Jul;6(7):927-33. doi: 10.1105/tpc.6.7.927.
The RPS3 and RPM1 disease resistance loci of Arabidopsis confer resistance to Pseudomonas syringae strains that carry the avirulence genes avrB and avrRpm1, respectively. We have previously shown that RPS3 and RPM1 are closely linked genetically. Here, we show that RPS3 and RPM1 are in fact the same gene. We screened a mutagenized Arabidopsis population with a P. syringae strain carrying avrB and found 12 susceptible mutants. All 12 mutants were also susceptible to an isogenic strain carrying avrRpm1, indicating a loss of both RPS3 and RPM1 functions. No mutants were recovered that lost only RPS3 function. Genetic analysis of four independent mutants revealed that the lesions were in RPS3. Thus, a single gene in Arabidopsis confers resistance that is specific to two distinct pathogen avirulence genes--a gene-for-genes interaction. This observation suggests that the RPS3/RPM1 gene product can bind multiple pathogen ligands, or alternatively, that it does not function as a receptor.
拟南芥的RPS3和RPM1抗病基因座分别赋予对携带无毒基因avrB和avrRpm1的丁香假单胞菌菌株的抗性。我们之前已经表明RPS3和RPM1在遗传上紧密连锁。在此，我们表明RPS3和RPM1实际上是同一个基因。我们用携带avrB的丁香假单胞菌菌株筛选了诱变的拟南芥群体，发现了12个感病突变体。所有12个突变体对携带avrRpm1的同基因菌株也敏感，表明RPS3和RPM1功能均丧失。未获得仅丧失RPS3功能的突变体。对四个独立突变体的遗传分析表明，损伤位于RPS3中。因此，拟南芥中的一个单一基因赋予对两种不同病原体无毒基因的特异性抗性——一种基因对基因的相互作用。这一观察结果表明，RPS3/RPM1基因产物可以结合多种病原体配体，或者，它不作为受体发挥作用。
