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草业学报 ›› 2026, Vol. 35 ›› Issue (10): 144-155.DOI: 10.11686/cyxb2025436

• 研究论文 • 上一篇    

柱花草SgNAC1基因的耐盐功能研究

王艺华1(), 任慈1, 张盼玉1, 刘翠玲1, 何亮亮1, 李洁仪1, 刘超1, 陈曙1,2,3()   

  1. 1.华南农业大学林学与风景园林学院,广东 广州 510642
    2.广东省草业工程技术研究中心,广东 广州 510642
    3.华南农业大学中山创新中心,广东 中山 528478
  • 收稿日期:2025-10-21 修回日期:2025-12-05 出版日期:2026-10-20 发布日期:2026-09-09
  • 通讯作者: 陈曙
  • 作者简介:E-mail: shuchen@scau.edu.cn
    王艺华(2001-),女,河南新乡人,在读硕士。E-mail: wang_yihua2026@163.com
  • 基金资助:
    国家自然科学基金(31601990);广东省基础与应用基础研究基金自然科学基金(2025A1515010836);广东省基础与应用基础研究基金自然科学基金(2023A1515140005);广州市科技计划项目(2024E04J1233)

A functional study of the role of SgNAC1 in salt tolerance in Stylosanthes

Yi-hua WANG1(), Ci REN1, Pan-yu ZHANG1, Cui-ling LIU1, Liang-liang HE1, Jie-yi LI1, Chao LIU1, Shu CHEN1,2,3()   

  1. 1.College of Forestry and Landscape Architecture,South China Agricultural University,Guangzhou 510642,China
    2.Guangdong Engineering Research Center for Grassland Science,Guangzhou 510642,China
    3.South China Agricultural University,Zhongshan Innovation Center,Zhongshan 528478,China
  • Received:2025-10-21 Revised:2025-12-05 Online:2026-10-20 Published:2026-09-09
  • Contact: Shu CHEN

摘要:

在热带和亚热带地区,柱花草属是极具经济价值的豆科牧草,被誉为“热带苜蓿”,在饲草生产、水土保持、果园覆盖等领域发挥重要作用。随着全球盐碱地面积逐年扩大,盐胁迫导致柱花草生长受阻、产量下降,已成为限制其栽植推广的关键障碍,亟需挖掘耐盐关键基因并解析其功能。NAC转录因子是植物耐盐调控的核心家族,而柱花草SgNAC1的耐盐特性尚未明确。本研究通过实时荧光定量PCR分析SgNAC1基因在细茎柱花草株系‘YN02’叶片及茎中的表达模式。结果表明,盐胁迫(150 mmol·L-1 NaCl)处理后,叶片中SgNAC1基因表达量在2 h时降至最低,茎中表达量在6 h达到峰值;脱落酸(ABA)处理后,叶片和茎中SgNAC1基因表达量均在处理1 h达到最高,在ABA+NaCl复合处理后,叶片中SgNAC1基因表达量在处理0.5 h后达到峰值,茎中表达量在1 h出现第一个峰值,12 h出现第二个峰值。上述结果表明,茎中SgNAC1基因在12 h左右响应盐胁迫,在1 h左右响应ABA和ABA+NaCl胁迫;盐胁迫下叶片中SgNAC1基因表达量在2 h显著下降,推测可能受其他因素调控;ABA+NaCl 复合处理下茎中SgNAC1基因的双表达峰,可能是NaCl与ABA协同作用的结果。通过根癌农杆菌介导的叶盘法转化野生型烟草,成功获得SgNAC1过表达的转基因烟草株系(SgNAC1-OE)。对野生型和SgNAC1-OE烟草同时进行盐胁迫(300 mmol·L-1 NaCl)处理,测定处理前后叶片的各项生理指标发现,SgNAC1过表达显著提升了脯氨酸水平,增强了烟草耐盐能力。本研究明确了SgNAC1基因在柱花草不同组织中的表达特征,并通过转基因烟草验证了其耐盐功能,为柱花草耐盐机制解析及耐盐育种提供理论依据和基因资源。

关键词: 柱花草, SgNAC1基因, 转基因烟草, 基因表达, 耐盐性

Abstract:

Stylosanthes (stylo) is an economically important leguminous forage crop in tropical and subtropical regions. It plays critical roles in forage production, soil and water conservation, and orchard ground cover. Because its role is similar to that of alfalfa (Medicago sativa), stylo is often referred to as ‘tropical alfalfa’. With the continuing global expansion of saline-alkali land areas, salt stress reduces the growth and yield of stylo, and has become a key constraint on its cultivation and promotion. Therefore, it is urgent to identify key genes related to salt tolerance and clarify their functions. The NAC family of transcription factors is known to regulate salt tolerance, but the specific role of SgNAC1 in the salt tolerance of stylo remains unclear. In this study, we analyzed the transcript profiles of SgNAC1 in leaves and stems of the Stylosanthesguianensis line ‘YN02’ using quantitative real-time PCR. The results show that under salt stress (150 mmol·L-1 NaCl), the transcript abundance of SgNAC1 in leaves decreased to the lowest level at 2 hours after treatment (HAT), but peaked in stems at 6 HAT. After treatment with abscisic acid (ABA), the transcript abundance of SgNAC1 in both leaves and stems peaked at 1 HAT. In the combined ABA+NaCl treatment, the transcript abundance of SgNAC1 in leaves peaked at 0.5 HAT, whereas in stems, it exhibited two peaks at 1 HAT and 12 HAT. Thus, SgNAC1 in stems responded to salt stress at approximately 12 HAT, and to both ABA and ABA+NaCl at approximately 1 HAT. Under salt stress, the transcript abundance of SgNAC1 in leaves decreased significantly at 2 HAT, implying that it may be regulated by other factors. The dual expression peaks of SgNAC1 in stems after treatment with ABA+NaCl may indicate a synergistic effect of NaCl and ABA. Transgenic tobacco (Nicotiana tabacum) lines overexpressing SgNAC1 (SgNAC1-OE) were obtained by transforming wild-type tobacco via the Agrobacterium tumefaciens-mediated leaf disc method. When both wild-type and SgNAC1-OE tobacco plants were subjected to salt stress (300 mmol·L-1 NaCl), the SgNAC1-OE tobacco plants showed significantly increased proline levels and salt tolerance, compared with the wild-type plants. The results of this study reveal the transcript profiles of SgNAC1 in different tissues of stylo, and the experiments with transgenic tobacco lines overexpressing SgNAC1 confirm its ability to increase salt tolerance. Together, our results provide a theoretical basis for further research on salt tolerance mechanisms, and identify a genetic resource for breeding salt-tolerant stylo.

Key words: Stylosanthes, SgNAC1 gene, transgenic tobacco, gene expression, salt tolerance