Wang Y Q, Zhang X F, Li N, Liu X
Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University, Beijing 100193, China.
Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University, Beijing 100193, China.
J Plant Physiol. 2017 Feb;209:105-114. doi: 10.1016/j.jplph.2016.11.011. Epub 2016 Dec 7.
Bacterial spot of tomato (Solanum lycopersicum L.) caused by several Xanthomonas species is one of the most destructive diseases. Genes regulating the hypersensitive resistance and field resistance to X. perforans race T3 have been intensively investigated over the last decade. However, a comparative analysis of cellular responses to the pathogen in susceptible and resistant hosts has not been completed, which prevents the detailed understanding of the interactions between the pathogen and tomato plants. In this study, the characteristics of lesions, stomata, and pathogen colonization in hypersensitive response (HR) PI 128216, field-resistant PI 114490, and susceptible OH 88119 tomato plants after inoculation with green fluorescent protein-labeled X. perforans race T3 bacteria were investigated. Significant differences in developmental processes and the micromorphology of spot lesions among three tomato lines were observed. Our results suggested that the faster lesion development in OH 88119 plants compared with that of the other two lines was associated with a greater increase in the stomatal apertures over a longer period following bacterial inoculation. The depth of bacterial colonization and pathogen density inside infected leaves in OH 88119 were also significantly different from that of resistant tomato plants. Determination of the ultrastructural responses to X. perforans among three tomato lines revealed that cell wall defense response was the main difference between resistant and susceptible tomato lines. These results may provide fundamental information for understanding the cellular and molecular mechanisms regulating tomato responses to X. perforans race T3.
由多种黄单胞菌引起的番茄细菌性斑点病是最具毁灭性的病害之一。在过去十年中，人们对调控番茄对穿孔黄单胞菌T3小种的过敏反应抗性和田间抗性的基因进行了深入研究。然而，尚未完成对感病和抗病寄主中细胞对病原体反应的比较分析，这妨碍了对病原体与番茄植株之间相互作用的详细了解。在本研究中，对接种绿色荧光蛋白标记的穿孔黄单胞菌T3小种细菌后的过敏反应（HR）PI 128216、田间抗性PI 114490和感病OH 88119番茄植株的病斑、气孔和病原体定殖特征进行了研究。观察到三个番茄品系在病斑发育过程和微观形态上存在显著差异。我们的结果表明，与其他两个品系相比，OH 88119植株病斑发展更快，这与细菌接种后较长时间内气孔孔径的更大增加有关。OH 88119中感染叶片内细菌定殖深度和病原体密度也与抗性番茄植株显著不同。对三个番茄品系对穿孔黄单胞菌的超微结构反应的测定表明，细胞壁防御反应是抗性和感病番茄品系之间的主要差异。这些结果可能为理解调控番茄对穿孔黄单胞菌T3小种反应的细胞和分子机制提供基础信息。
