Zhang Sufang, Yan Shanshan, Zhang Li, Yan Pingyu, Zhang Hanguo, Zhang Lei
State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University), Harbin, 150040, China.
Shandong Xiandai University, Jinan, 250000, China.
BMC Plant Biol. 2025 May 6;25(1):592. doi: 10.1186/s12870-025-06591-x.
Larch (Larix gmelinii (Rupr.) Kuzen.) is an important timber and ecological tree species in northern China. Excellent germplasm resources have been acquired through time-consuming traditional breeding. Molecular breeding offers a promising approach to shorten the breeding cycle and achieve genetic improvements more efficiently. MicroRNAs (miRNAs) are non-coding, single-stranded small RNAs that primarily affect plant growth and stress resistance, including drought stress. However, the study of miRNAs in larch under drought stress has not been well explored.
In this study, to investigate the function of Lol-miR11467 under PEG osmotic stress in larch, embryogenic callus tissue of Larix kaempferi 3 × L. gmelinii 9 was employed as the experimental material, serving as the explants for this study. Lol-miR11467 was transferred into the explants using an Agrobacterium-mediated method to determine the physiological changes and survey gene expression changes in overexpressing Lol-miR11467 cell lines. The results showed that the fresh weight, peroxidase (POD), soluble protein and soluble sugar content of the overexpressing Lol-miR11467 were lower than that of the wild-type, while malondialdehyde (MDA) content increased under PEG osmotic stress. Transcriptome analysis showed that genes associated with phenylpropanoid metabolism, transcription factors, oxidoreductase, plant hormone signal transduction, glucose metabolism and bioprotective macromolecules were mainly downregulated in Lol-miR11467 cell lines.
Overall, these results indicated that the drought resistance of the overexpressing Lol-miR11467 cell lines was reduced. This study's findings might provide a foundation for understanding the molecular mechanisms of miRNAs under PEG osmotic stress in larch, potentially contributing to the development of strategies for improving plant resilience to environmental stresses.
落叶松（Larix gmelinii (Rupr.) Kuzen.）是中国北方重要的用材和生态树种。通过耗时的传统育种已获得了优良种质资源。分子育种为缩短育种周期和更高效地实现遗传改良提供了一种有前景的方法。微小RNA（miRNA）是一类非编码单链小RNA，主要影响植物生长和抗逆性，包括干旱胁迫。然而，落叶松在干旱胁迫下miRNA的研究尚未得到充分探索。
在本研究中，为了探究落叶松中Lol-miR11467在PEG渗透胁迫下的功能，以日本落叶松3×兴安落叶松9的胚性愈伤组织为实验材料，作为本研究的外植体。采用农杆菌介导的方法将Lol-miR11467导入外植体，以确定过表达Lol-miR11467细胞系中的生理变化并检测基因表达变化。结果表明，在PEG渗透胁迫下，过表达Lol-miR11467的鲜重、过氧化物酶（POD）、可溶性蛋白和可溶性糖含量均低于野生型，而丙二醛（MDA）含量增加。转录组分析表明，在Lol-miR11467细胞系中，与苯丙烷代谢、转录因子、氧化还原酶、植物激素信号转导、葡萄糖代谢和生物保护大分子相关的基因主要下调。
总体而言，这些结果表明过表达Lol-miR11467细胞系的抗旱性降低。本研究结果可能为理解落叶松在PEG渗透胁迫下miRNA的分子机制提供基础，可能有助于制定提高植物对环境胁迫抗性的策略。
