生物技术通报 ›› 2025, Vol. 41 ›› Issue (5): 165-174.doi: 10.13560/j.cnki.biotech.bull.1985.2024-1066

• 研究报告 • 上一篇    

2,4-表油菜素内酯对镉胁迫下胡萝卜幼苗生理特性的影响

周志国(), 樊双虎, 邓晨, 冯雪()   

  1. 廊坊师范学院生命科学学院,廊坊 065000
  • 收稿日期:2024-11-06 出版日期:2025-05-26 发布日期:2025-06-05
  • 通讯作者: 冯雪,女,副教授,研究方向 :蔬菜栽培;E-mail: fengxue1978@126.com
  • 作者简介:周志国,男,博士,副教授,研究方向 :蔬菜学;E-mail: zhiguo__zhou@163.com
  • 基金资助:
    河北省教育厅青年拔尖人才项目(BJK2024187)

Effects of Exogenous 24-Epibrassinolide on Physiological Characteristics of Daucus carota L. Seedlings under Cadmium Stress

ZHOU Zhi-guo(), FAN Shuang-hu, DENG Chen, FENG Xue()   

  1. College of Life Science, Langfang Normal University, Langfang 065000
  • Received:2024-11-06 Published:2025-05-26 Online:2025-06-05

摘要:

目的 分析不同浓度的2,4-表油菜素内酯(2,4-EBR)对镉胁迫下胡萝卜幼苗的生长特性、生理指标及镉吸收转运相关基因表达的影响,为胡萝卜对镉抗性的相关研究提供理论支撑。 方法 以胡萝卜‘红芯四号’为试验材料,采用实验室水培的方法,研究不同浓度(0.1、0.5、1和1.5 μmol/L)2,4-EBR对CdCl2胁迫下胡萝卜幼苗生长特性、光合作用、抗氧化酶活性以及镉吸收转运相关基因表达的影响。 结果 胡萝卜幼苗在0.1 mmol/L镉胁迫条件下生长受到显著抑制,外源施加1 μmol/L 2,4-EBR可以抑制镉离子的吸收和转运,促进胡萝卜幼苗根长和株高的增加,提高叶片SOD、POD、CAT和APX的活性,增加光合色素含量并提高叶片光合效率,抑制镉吸收转运相关基因DcHMA3DcHMA4DcCAX2DcCAX4的表达,维持植物体氧化还原代谢途径平衡。 结论 2,4-EBR可促进胡萝卜根茎生长,增强抗氧化酶活性,提高光合效率,调节GSH-PCs代谢途径以及调控相关基因表达量,从而缓解胡萝卜幼苗在镉胁迫下的伤害,而且最适宜的2,4-EBR处理浓度为1 μmol/L。

关键词: 镉胁迫, 2,4-表油菜素内酯, 胡萝卜, 生长和生理特性, 基因表达

Abstract:

Objective This study is aimed to investigate the impact of varying concentrations of 2,4-epibrassinolide on growth indices, physiological parameters, and the expression of cadmium (Cd) uptake and transporter-related genes in carrot (Daucus carota L.) seedlings subjected to Cd stress. The findings provide theoretical insights into Cd resistance research in carrots. Method The "Hongxin 4" carrot cultivar (Daucus carota L.) was selected for the experimental materials. Using a hydroponic system, we examined the effects of different concentrations (0.1, 0.5, 1, and 1.5 μmol/L) of 2,4-epibrassinolide on the growth traits, physiological indicators, and photosynthesis of carrot seedlings under 0.1 mmol/L CdCl2 stress. Result The growth of carrot seedlings was significantly inhibited under 0.1 mmol/L Cd stress. However, the exogenous application of 1 μmol/L 2,4-epibrassinolide inhibited cadmium ion absorption and transport, promoted the root length and plant height, elevated the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in the leaves, increased the contents of photosynthetic pigments, enhanced the photosynthetic efficiency, and suppressed the expressions of Cd uptake and transport-related genes (DcHMA3, DcHMA4, DcCAX2 and DcCAX4),thereby maintaining the balance of redox metabolic pathways in the plants. Conclusion 2,4-epibrassinolide promoted carrot root growth, enhanced antioxidant enzyme activity, improved photosynthetic efficiency, regulated the glutathione-phytochelatin (GSH-PC) metabolic pathway, and modulated the expressions of related genes to alleviate Cd stress-induced damage in carrot seedlings. The optimal concentration of 2,4-epibrassinolid for carrots was found to be 1 μmol/L.

Key words: cadmium stress, 2,4-epibrassinolide, carrot, physiological characteristics, gene expression