Wang Zeqi, Fu Tiantian, Wang Chun, Yang Yuzhang, Yang Xiaoqian, Liu Jiahao, Yu Ruen, Ji Hongkun, Wang Yuanlong, Wang Tianliang, Li Jieru, Wang Yanwei
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 100083, China.
Puyang Academy of Agriculture and Forestry Sciences, China.
Plant Sci. 2025 Oct;359:112630. doi: 10.1016/j.plantsci.2025.112630. Epub 2025 Jun 27.
MicroRNAs (miRNAs) play a crucial role in plant defense against biotic stress, yet their regulatory mechanisms in poplar resistance to Anoplophora glabripennis (ALB) remain poorly understood. This study investigated the miRNA expression of two distinct poplar varieties, namely Populus tomentosa (resistant) and Populus × euramericana '74/76' (poplar 107, susceptible), after ALB infestation. Small RNA sequencing analysis identified 401 miRNAs in both P. tomentosa and poplar 107. Following insect stress, 34 miRNAs were specifically differentially expressed in P. tomentosa, and 17 miRNAs were differentially expressed in poplar 107. Additionally, 7 miRNAs from the miR168, miR398, and miR482 families were found to be differentially expressed in both poplar varieties and were associated with the response to insect stress. Functional annotation revealed significant enrichment of miRNA target genes in metabolic pathways and secondary metabolite biosynthesis in both poplar varieties. However, their responses to ALB stress were not entirely identical. Specifically, the MAPK signaling pathway was enriched in P. tomentosa, but not in poplar 107. Furthermore, a combined miRNA/mRNA analysis identified 36 differentially expressed miRNAs negatively correlated with 31 target genes. Most target genes were linked to LRR receptor-like serine, receptor-like protein, auxin response factor, and polyphenol oxidase, chloroplastic. Via transient expression validation, miR398b, miR168a, and miR482c were found to target CSD1, AGO1, and LRR, respectively. This study provides fundamental insights into the molecular mechanisms underlying pest resistance in poplar and identifies potential targets for future genetic improvement strategies.
微小RNA（miRNA）在植物抵御生物胁迫中发挥着关键作用，然而它们在杨树对光肩星天牛（ALB）抗性中的调控机制仍知之甚少。本研究调查了两种不同杨树品种，即毛白杨（抗性）和欧美杨‘74/76’（杨树107，易感）在受到ALB侵害后的miRNA表达情况。小RNA测序分析在毛白杨和杨树107中均鉴定出401个miRNA。昆虫胁迫后，34个miRNA在毛白杨中特异性差异表达，17个miRNA在杨树107中差异表达。此外，发现来自miR168、miR398和miR482家族的7个miRNA在两个杨树品种中均差异表达，且与对昆虫胁迫的反应相关。功能注释显示，两个杨树品种中miRNA靶基因在代谢途径和次生代谢物生物合成中显著富集。然而，它们对ALB胁迫的反应并不完全相同。具体而言，丝裂原活化蛋白激酶（MAPK）信号通路在毛白杨中富集，但在杨树107中未富集。此外，miRNA/mRNA联合分析鉴定出36个差异表达的miRNA与31个靶基因呈负相关。大多数靶基因与富含亮氨酸重复序列（LRR）的受体样丝氨酸、受体样蛋白、生长素响应因子和叶绿体多酚氧化酶有关。通过瞬时表达验证，发现miR398b、miR168a和miR482c分别靶向铜锌超氧化物歧化酶1（CSD1）、AGO1和LRR。本研究为杨树抗虫分子机制提供了基础见解，并确定了未来遗传改良策略的潜在靶点。
