Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture and Key Laboratory of Crop Genetics and Breeding and Comprehensive Utilization, Ministry of Education, College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
BMC Genomics. 2017 Oct 30;18(1):833. doi: 10.1186/s12864-017-4231-3.
Cold is a major abiotic stress limiting the production of tropical and subtropical crops in new production areas. Sugarcane (Saccharum spp.) originates from the tropics but is cultivated primarily in the sub-tropics where it frequently encounters cold stress. Besides regulating plant growth, miRNAs play an important role in environmental adaption.
In this study, a total of 412 sugarcane miRNAs, including 261 known and 151 novel miRNAs, were obtained from 4 small RNA libraries through the Illumina sequencing method. Among them, 62 exhibited significant differential expression under cold stress, with 34 being upregulated and 28 being downregulated. The expression of 13 miRNAs and 12 corresponding targets was validated by RT-qPCR, with the majority being consistent with the sequencing data. GO and KEGG analysis indicated that these miRNAs were involved in stress-related biological pathways. To further investigate the involvement of these miRNAs in tolerance to abiotic stresses, sugarcane miR156 was selected for functional analysis. RT-qPCR revealed that miR156 levels increased in sugarcane during cold, salt and drought stress treatments. Nicotiana benthamiana plants transiently overexpressing miR156 exhibited better growth status, lower ROS levels, higher anthocyanin contents as well as the induction of some cold-responsive genes, suggesting its positive role in the plant cold stress response.
This study provides a global view of the association of miRNA expression with the sugarcane response to cold stress. The findings have enriched the present miRNA resource and have made an attempt to verify the involvement of miR156 in plant response to cold stress.
寒冷是限制热带和亚热带作物在新产区生产的主要非生物胁迫因素。甘蔗（Saccharum spp.）起源于热带地区，但主要在亚热带地区种植，在亚热带地区，它经常会遇到冷胁迫。除了调节植物生长外，miRNA 在环境适应中也起着重要作用。
本研究通过 Illumina 测序方法，从 4 个小 RNA 文库中共获得 412 个甘蔗 miRNA，包括 261 个已知 miRNA 和 151 个新 miRNA。其中，62 个 miRNA 在冷胁迫下表现出显著差异表达，其中 34 个上调，28 个下调。通过 RT-qPCR 验证了 13 个 miRNA 和 12 个相应靶基因的表达，大部分与测序数据一致。GO 和 KEGG 分析表明，这些 miRNA 参与了与胁迫相关的生物途径。为了进一步研究这些 miRNA 参与非生物胁迫耐受性的机制，选择了甘蔗 miR156 进行功能分析。RT-qPCR 结果显示，miR156 在甘蔗冷、盐和干旱胁迫处理过程中表达量增加。瞬时过表达 miR156 的拟南芥植株表现出更好的生长状态、更低的 ROS 水平、更高的花青素含量以及一些冷响应基因的诱导，表明其在植物冷胁迫响应中起积极作用。
本研究提供了 miRNA 表达与甘蔗冷胁迫响应之间关联的全面视图。研究结果丰富了现有的 miRNA 资源，并尝试验证了 miR156 参与植物冷胁迫响应。
