Yang Xiaoqian, Li Yiwen, Yu Ruen, Zhang Lichun, Yang Yuzhang, Xiao Dandan, Li Aining, Wang Yanwei
National Engineering Research Center of Tree Breeding and Ecological Restoration, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of National Forestry and Grassland Administration, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China.
Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, China.
Plant Cell Environ. 2023 Jan;46(1):306-321. doi: 10.1111/pce.14460. Epub 2022 Oct 25.
Different poplar varieties vary in their tolerance to certain pathogens. However, knowledge about molecular regulation and critical responses of resistant poplars during pathogen infection remains scarce. To investigate adaptive responses to canker disease caused by the bacterium Lonsdalea populi, we screened three poplar varieties with contrasting tolerance, including Populus deltoides. 'Zhonglin 2025' (2025), Populus × Euramericana. '74/76' (107) and Populus tomentosa cv 'henan' (P. tomentosa). Transcriptomic analysis revealed significant changes in the expression levels of defence-related genes in different poplar varieties in response to infection, which reshaped the PTI and ETI processes. Intriguingly, photosynthesis-related genes were found to be highly expressed in the resistant variety, whereas the opposite was observed in the susceptible variety. Susceptible poplars maintained the activation of defence-related genes during early period of onset, which restricted the expression of photosynthesis-related and auxin signal-related genes. Furthermore, combined with metabolomic analysis, differences in the content of antibacterial substances and key differentially expressed genes in phenylpropane and flavonoid biosynthesis pathways were identified. Delayed induction of catechin in the susceptible variety and it's in vitro antibacterial activity were considered to be one of the important reasons for the differences in resistance to L. populi compared with the resistant variety, which is of practical interest for tree breeding. Moreover, the trade-off between growth and defence observed among the three poplar varieties during infection provides new insights into the multilevel regulatory circuits in tree-pathogen interactions.
不同杨树品种对某些病原体的耐受性存在差异。然而，关于抗性杨树在病原体感染期间的分子调控和关键反应的知识仍然匮乏。为了研究杨树对由杨树溃疡病菌引起的溃疡病的适应性反应，我们筛选了三个耐受性不同的杨树品种，包括美洲黑杨‘中林2025’（2025）、欧美杨‘74/76’（107）和毛白杨‘河南’（毛白杨）。转录组分析揭示了不同杨树品种在感染后防御相关基因表达水平的显著变化，这些变化重塑了PTI和ETI过程。有趣的是，发现光合作用相关基因在抗性品种中高表达，而在感病品种中则相反。感病杨树在发病早期维持防御相关基因的激活，这限制了光合作用相关基因和生长素信号相关基因的表达。此外，结合代谢组分析，鉴定了苯丙烷和类黄酮生物合成途径中抗菌物质含量和关键差异表达基因的差异。感病品种中儿茶素的诱导延迟及其体外抗菌活性被认为是与抗性品种相比对杨树溃疡病菌抗性差异的重要原因之一，这对树木育种具有实际意义。此外，在感染期间三个杨树品种中观察到的生长与防御之间的权衡为树木与病原体相互作用中的多层次调控回路提供了新的见解。
