Qianhui Xu¹ , Fuli Chang² , Xiaowei Huo¹ , Ke Zhou¹ , Yanwei Wang¹

1 Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing, 100083, China
2 Jiaozuo Administration, Taihang Mountains National Nature Reserve, Jiaozuo, 454000, China
Author    Correspondence author
Tree Genetics and Molecular Breeding, 2022, Vol. 12, No. 4   doi: 10.5376/tgmb.2022.12.0004
Received: 24 Feb., 2022    Accepted: 28 Feb., 2022    Published: 20 Mar., 2022

This article was first published in Molecular Plant Breeding in Chinese, and here was authorized to translate and publish the paper in English under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Xu Q.H., Chang F.L., Huo X.W., Zhou K., and Wang Y.W., 2022, Prediction and analysis of miRNA targets in poplar in response to the infection of Lonsdalea quercina subsp. Populi, Tree Genetics and Molecular Breeding, 12(4): 1-12 (doi: 10.5376/tgmb.2022.12.0004)

Euramerican poplar bacterial canker disease caused by Lonsdalea quercina subsp. Populi is one of the stem diseases and seriously harmful to the growth and survival of poplar. MiRNAs play crucial roles in the regulation of the stress response of plants. To identify target genes of miRNAs responsive to the infection of this pathogen and provide candidate genes to the molecular breeding of forest disease resistance, the mature sequences of poplar miRNAs in miRBase database were used as probes to in silico predict the differentially expressed targets in poplar ‘Zhonglin 46’ inoculated with bacterial canker by using psRNATarget in this investigation. A total of 566 target genes of 276 miRNAs belonging to 127 miRNA families were screened, and these targets were found to be involved in multiple pathways such as plant pathogen interaction, plant hormone signaling, and phenylpropanoid biosynthesis, suggesting that these miRNAs were involved in the regulation of the response to L. quercina infection. Combined with GO analysis, KEGG pathway enrichment and gene function annotation of target genes, it was showed that miRNAs including miR482, miR6459, miR7812 and miR7835 were predicted to target genes encoding RPS2, NBS-LRR, AUX1, CCR, and Ca²⁺ transmembrane transport protein genes, which were involved in the resistance regulation of poplar to L. quercina infection. Six of the nine differentially expressed genes targeted by miR7835 encode the CCR enzyme in the phenylpropanol biosynthesis pathway, which might be involved in the defense response of poplars by affecting the synthesis of lignin. The miRNA:mRNA regulatory gene pairs found in this investigation enlarged the gene resources of molecular breeding of forest disease resistance, and provided new clues for the research of the molecular regulatory mechanism of disease resistance in trees.

Poplar; miRNA; Target gene; Lonsdalea quercina subsp. Populi