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草业学报 ›› 2024, Vol. 33 ›› Issue (11): 123-134.DOI: 10.11686/cyxb2023498

• 研究论文 • 上一篇    

异源表达偏关苜蓿miR397-5p增强烟草干旱胁迫耐受能力

王雨欣1(), 陶佳丽2, 朱慧森1(), 许涛1(), 张逸飞1, 岑慧芳1   

  1. 1.山西农业大学草业学院,山西 太谷 030801
    2.山西工程技术学院矿业工程系,山西 阳泉 045000
  • 收稿日期:2023-12-26 修回日期:2024-03-18 出版日期:2024-11-20 发布日期:2024-09-09
  • 通讯作者: 朱慧森,许涛
  • 作者简介:xutao@sxau.edu.cn
    E-mail: zhuhuisen@126.com
    王雨欣(1999-),女,河北承德人,在读硕士。E-mail: wyx18034264192@163.com
  • 基金资助:
    国家自然科学基金(32071872);山西省中央引导地方科技发展资金项目(YDZJSX2022B006);山西重点研发计划课题(202102140601006-3);山西省基础研究计划青年科学基金项目(20210302124607);山西省“来晋奖励”科研项目(SXBYKY2022118);2022年度山西省研究生教育创新项目(2022Y334)

Heterologous expression of miR397-5p from Medicago sativa cv. ‘Pianguan’ improves the drought tolerance of tobacco

Yu-xin WANG1(), Jia-li TAO2, Hui-sen ZHU1(), Tao XU1(), Yi-fei ZHANG1, Hui-fang CEN1   

  1. 1.College of Grassland Science,Shanxi Agricultural University,Taigu 030801,China
    2.Department of Mining Engineering,Shanxi Institute of Technology,Yangquan 045000,China
  • Received:2023-12-26 Revised:2024-03-18 Online:2024-11-20 Published:2024-09-09
  • Contact: Hui-sen ZHU,Tao XU

摘要:

偏关苜蓿是山西地方优良种质,具有抗逆性强、适应性强、耐瘠薄的特点,挖掘偏关苜蓿抗旱相关基因,并将其应用于紫花苜蓿遗传改良,对于优异新种质创制具有重要意义。利用miRNA测序从偏关苜蓿中筛选出miR397-5p为潜在的干旱胁迫响应基因,通过转基因烟草验证了偏关苜蓿miR397-5p对干旱胁迫的响应,并找到其潜在的下游调控因子。结果表明:干旱胁迫处理后,过表达miR397-5p烟草的可溶性糖、可溶性蛋白、脯氨酸等渗透调节物质含量增加,过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)的活性提高,丙二醛(MDA)含量降低。干旱胁迫下,miR397-5p下调其靶基因LAC4的表达;在过表达miR397-5p烟草中,PAL4CL、CCRCADHCTF5H、PAO等大部分木质素生物合成途径关键酶基因相对表达量下调,仅C4HCCoAOMTCOMT等基因相对表达量上调,同时,过表达miR397-5p烟草木质素含量降低,大部分基因相对表达量和木质素含量具有一致的变化趋势。由此推断偏关苜蓿可能通过miR397-5p-LAC4调控木质素积累响应干旱胁迫,但具体内在机制有待进一步研究。研究结果可为紫花苜蓿遗传改良提供基因资源,对于优异新种质的创制具有潜在价值。

关键词: 偏关苜蓿, 干旱胁迫, miR397-5p, 木质素

Abstract:

Medicago sativa cv.‘Pianguan’ is a well-regarded local germplasm in Shanxi Province, known for its strong stress resistance, adaptability, and resistance to barren soils. It is crucial to identify genes related to drought resistance in M. sativa cv. ‘Pianguan’, so that they can be utilized for the genetic enhancement of alfalfa, thereby facilitating the development of new germplasm. In this study, miR397-5p was identified as a potential microRNA responsive to drought stress in M. sativa cv. ‘Pianguan’ through miRNA sequencing analysis. The responsiveness of miR397-5p from M. sativa cv. ‘Pianguan’ to drought stress was validated in transgenic tobacco, and its potential downstream target, and its effects, were identified. After drought stress, miR397-5p-overexpressing tobacco showed elevated levels of osmotic regulators, including soluble sugars, soluble proteins, and proline. Additionally, the activities of the antioxidant enzymes catalase, superoxide dismutase, and peroxidase were increased, while the malondialdehyde content was decreased. Under drought stress, miR397-5p decreased the expression of its target gene LAC4. In miR397-5p-overexpressing tobacco, most genes encoding key enzymes in the lignin biosynthesis pathway (PAL4CLCCRCADHCTF5H, and PAOshowed decreased transcript levels, while genes such as C4HCCoAOMTCOMTand others exhibited increased transcript levels. Additionally, the lignin content was decreased in miR397-5p-overexpressing tobacco. The transcript levels of most of these genes and lignin content exhibited consistent trends.It was inferred that M. sativa cv. ‘Pianguan’ may regulate lignin accumulation in response to drought stress through miR397-5p-LAC4, but the specific underlying mechanism needs to be further investigated. Further research is required to clarify the mechanism of this response. The results of this study may provide a genetic resource for the genetic improvement of alfalfa, which is potentially valuable for the creation of excellent new germplasm.

Key words: Medicago sativa cv.‘Pianguan’, drought stress, miR397-5p, lignin