Clarke Christopher R, Kramer Charles G, Kotha Raghavendhar R, Luthria Devanand L
Genetic Improvement for Fruits and Vegetables Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD.
Food Composition and Methods Development Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD.
Phytopathology. 2022 Nov;112(11):2288-2295. doi: 10.1094/PHYTO-03-22-0072-R. Epub 2022 Nov 22.
Several species of cause common scab, a major disease of potato, primarily through the phytotoxic effects of the phytotoxin thaxtomin A. Several phytopathogenic species have also been implicated as the causative agents of scab diseases of taproot crops including beet, carrot, radish, parsnip, and turnip. But the molecular mechanisms employed by to infect these crops is unknown. In this work, we tested the hypothesis that thaxtomin A biosynthesis is also necessary for -caused scab of beet, carrot, radish, and turnip. Thaxtomin A induced plant stunting and cell death of all four of these species. mutants in which the transcriptional regulator of thaxtomin A biosynthesis is disrupted were nonvirulent on all four crops, and complementation of the transcriptional regulator rescued thaxtomin A biosynthesis and plant pathogenicity to wild-type levels. These results demonstrate that thaxtomin A is the primary virulence determinant of scab disease of these other crops.
几种链格孢菌会引发马铃薯的主要病害——普通疮痂病，主要是通过致病毒素thaxtomin A的植物毒性作用。几种植物病原性链格孢菌也被认为是包括甜菜、胡萝卜、萝卜、防风草和芜菁在内的主根作物疮痂病的病原体。但是链格孢菌感染这些作物所采用的分子机制尚不清楚。在这项研究中，我们验证了这样一个假设，即thaxtomin A的生物合成对于链格孢菌引起的甜菜、胡萝卜、萝卜和芜菁疮痂病也是必需的。Thaxtomin A会导致这四个物种的植物生长迟缓以及细胞死亡。在thaxtomin A生物合成的转录调节因子被破坏的突变体对所有这四种作物都没有致病性，而转录调节因子的互补作用将thaxtomin A的生物合成和植物致病性恢复到了野生型水平。这些结果表明，thaxtomin A是这些其他作物疮痂病的主要毒力决定因素。
