Hussain Muhammad Azhar, Huang Yong, Luo Dan, Mehmood Sundas Saher, Raza Ali, Duan Liu, Zhang Xuekun, Cheng Yong, Cheng Hongtao, Zou Xiling, Ding Xiaoyu, Zeng Liu, Wu Bian, Hu Keming, Lv Yan
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences (CAAS), Wuhan, China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China.
Plant Biotechnol J. 2025 Jun;23(6):1968-1987. doi: 10.1111/pbi.70017. Epub 2025 Mar 4.
Brassica napus L. (B. napus) is a major edible oil crop grown around the southern part of China, which often faces cold stress, posing potential damage to vegetative tissues. To sustain growth and reproduction, a detailed understanding of fundamental regulatory processes in B. napus against long-term low temperature (LT) stress is necessary for breeders to adjust the level of LT adaption in a given region and is therefore of great economic importance. Till now, studies on microRNAs (miRNAs) in coping with LT adaption in B. napus are limited. Here, we performed an in-depth analysis on two B. napus varieties with distinct adaptability to LT stress. Through integration of RNA sequencing (RNA-seq) and small RNA-sequencing (sRNA-seq), we identified 106 modules comprising differentially expressed miRNAs and corresponding potential targets based on strong negative correlations between their dynamic expression patterns. Specifically, we demonstrated that Bna-miR397a post-transcriptionally regulates a LACCASE (LAC) gene, BnaLAC2, to enhance the adaption to LT stresses in B. napus by reducing the total lignin remodelling and ROS homeostasis. In addition, the miR397-LAC2 module was also proved to improve freezing tolerance of Arabidopsis, indicating a conserved role of miR397-LAC2 in Cruciferae plants. Overall, this work provides the first description of a miRNA-mediated-module signature for LT adaption and highlights the prominent role of laccase in future breeding programme of LT tolerant B. napus.
甘蓝型油菜（Brassica napus L.）是中国南方种植的一种主要食用油作物，它经常面临低温胁迫，对营养组织造成潜在损害。为了维持生长和繁殖，详细了解甘蓝型油菜应对长期低温（LT）胁迫的基本调控过程对于育种者在特定区域调整LT适应水平至关重要，因此具有重大经济意义。到目前为止，关于甘蓝型油菜中微小RNA（miRNA）应对LT适应的研究有限。在此，我们对两个对LT胁迫具有不同适应性的甘蓝型油菜品种进行了深入分析。通过整合RNA测序（RNA-seq）和小RNA测序（sRNA-seq），基于动态表达模式之间的强负相关性，我们鉴定出106个包含差异表达miRNA及其相应潜在靶标的模块。具体而言，我们证明了Bna-miR397a通过减少总木质素重塑和活性氧稳态，在转录后调控一个漆酶（LAC）基因BnaLAC2，以增强甘蓝型油菜对LT胁迫的适应性。此外，miR397-LAC2模块也被证明可提高拟南芥的抗冻性，表明miR397-LAC2在十字花科植物中具有保守作用。总体而言，这项工作首次描述了miRNA介导的LT适应模块特征，并突出了漆酶在未来耐LT甘蓝型油菜育种计划中的重要作用。
