State Key Laboratory of Tree Genetics and Breeding, 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.
Physiol Plant. 2024 Sep-Oct;176(5):e14498. doi: 10.1111/ppl.14498.
Canker caused by Lonsdalea populi has seriously reduced the economic and ecological benefits of poplar. MicroRNAs play vital roles in the response of plants to biotic stress. However, there is little research about the regulatory mechanism of miRNAs among different tree varieties upon pathogen infection. To dissect miRNAs involved in L. populi resistance, three poplar varieties, 2025 (susceptible), 107 (moderately resistant) and Populus. tomentosa cv 'henan' (resistant) were selected to elucidate the expression profiles of miRNAs using small RNA-seq. A total of 227 miRNAs were identified from all varieties. Intriguingly, miR160, miR169, miR171 and miR482b-5p were only identified in the resistant variety P. tomentosa upon pathogen infection, and these miRNAs might be important candidates for future investigation to improve the tolerance of poplar to L. populi. Among all identified miRNAs, 174 were differentially expressed in all varieties. Functional annotation analysis indicated that an array of miRNAs, including miR482, miR472, miR169, miR481, and miR172, should be involved in disease resistance and phytohormone signal transduction. Furthermore, correlation analysis of small RNA-seq and RNA-seq identified a handful of L. populi-responsive miRNAs and target genes, which exhibited that miR159 and miR172 played key roles in resistant variety P. tomentosa by targeting MYB and ERF, while miR6462c-5p and miR828 were related to the susceptibility of 2025 by targeting MYB. The comprehensive integration analysis in this research provides new insights into the regulatory pathways involved in the defence response of poplar to L. populi and offers crucial candidate miRNAs-target genes modules for poplar resistance improvement.
杨树溃疡病严重降低了杨树的经济效益和生态效益。MicroRNAs 在植物对生物胁迫的响应中发挥着重要作用。然而，关于不同树种在受到病原体感染时 miRNA 的调控机制的研究还很少。为了剖析与杨树叶锈病抗性相关的 miRNAs，本研究选用 2025（感病）、107（中度抗病）和 Populus. tomentosa cv 'henan'（抗病）三个杨树品种，利用小 RNA-seq 阐明了 miRNA 的表达谱。从所有品种中共鉴定出 227 个 miRNA。有趣的是，miR160、miR169、miR171 和 miR482b-5p 仅在抗病品种 P. tomentosa 受到病原体感染时被鉴定出来，这些 miRNA 可能是未来提高杨树对杨树叶锈病抗性的重要候选者。在所有鉴定出的 miRNA 中，有 174 个在所有品种中差异表达。功能注释分析表明，包括 miR482、miR472、miR169、miR481 和 miR172 在内的一系列 miRNA 可能参与了抗病性和植物激素信号转导。此外，小 RNA-seq 和 RNA-seq 的相关性分析鉴定出少数对 Lonsdalea populi 有响应的 miRNA 和靶基因，表明 miR159 和 miR172 通过靶向 MYB 和 ERF 基因在抗病品种 P. tomentosa 中发挥关键作用，而 miR6462c-5p 和 miR828 通过靶向 MYB 基因与 2025 的感病性有关。本研究的综合整合分析为杨树对 Lonsdalea populi 防御反应的调控途径提供了新的见解，并为提高杨树抗性提供了关键的候选 miRNA-靶基因模块。
