高级检索

    2−吡嗪羧酸处理对采后‘三红蜜柚’汁胞糖保持与木质化延缓的影响

    Effects of 2-pyrazinecarboxylic acid treatment on juice sac sugar retention and lignification delay in postharvest ‘Sanhongmiyou’ pummelo

      摘要
    • 摘要:
      目的 ‘三红蜜柚’不耐贮藏，其果实成熟和采后贮藏过程常因木质素过度积累而导致汁胞木质化。本研究旨在探讨2−吡嗪羧酸处理对延缓贮藏期‘三红蜜柚’木质化及保持风味品质的效果。
      方法 以‘三红蜜柚’为试验材料，在室温条件下，用500 μmol·L−1 2−吡嗪羧酸溶液+0.1%(φ)吐温80溶液浸果2 min，以0.1%吐温80溶液浸泡2 min为对照。在采后0、4、8、12、16和20 d取样，测定汁胞糖组分含量、木质素含量以及木质素合成关键酶活性及其主要编码基因表达量的变化。
      结果 相比于对照，在贮藏期内2−吡嗪羧酸处理显著降低‘三红蜜柚’汁胞中的木质素含量。在采后20 d，对照组的木质素含量增加了87.41%，而处理组仅增加41.85%。酶活性和基因表达分析显示，相比于对照，2−吡嗪羧酸处理显著降低木质素合成关键酶(POD、F5H、CAD、CCoAOMT、C4H和4CL)活性，平均降低幅度分别为17.97%、9.14%、12.26%、29.39%、23.70%及27.10%，并且显著下调这些关键酶主要编码基因(CmPOD3、CmF5H1、CmCAD4、CmCAD5、CmCCoAOMT1、CmCYP73A16及Cm4CL2)的表达。此外，相比于对照，该处理显著提升葡萄糖、果糖、蔗糖及可溶性糖含量，平均提升幅度分别为21.33%、16.12%、12.78%及5.51%。相关性分析表明，木质素含量与其关键酶活性呈极显著正相关，木质素含量的增加与糖组分的减少呈显著负相关。
      结论 2−吡嗪羧酸通过显著下调木质素合成关键酶基因表达，有效抑制酶活性，延缓汁胞木质化进程，减少糖组分消耗，从而保持‘三红蜜柚’风味品质。本研究为揭示其作用机制及‘三红蜜柚’采后贮藏提供了科学依据和技术参考。

       

      Abstract:
      Objective The ‘Sanhongmiyou’ pummelo variety is not suitable for long-term storage due to juice sac lignification caused by excessive lignin accumulation during fruit maturation and postharvest storage. This study aimed to investigate the effects of 2-pyrazinecarboxylic acid treatment on delaying lignification and maintaining flavor quality in ‘Sanhongmiyou’ pummelo during storage.
      Method ‘Sanhongmiyou’ pummelo was used as the experimental material. Fruits were treated by immersing in 500 μmol·L−1 2-pyrazinecarboxylic acid solution + 0.1% (φ) tween 80 solution for 2 min at room temperature, with 0.1% tween 80 solution used as the control. Samples were collected at 0, 4, 8, 12, 16, and 20 days postharvest, and changes in juice sac sugar component contents, lignin content, as well as the activity of key enzymes associated with lignin biosynthesis and the expression levels of their primary coding genes were determined.
      Result Compared to control, 2-pyrazinecarboxylic acid treatment significantly reduced lignin content in the juice sacs of ‘Sanhongmiyou’ pummelo during storage. At 20 days postharvest, lignin content increased by 87.41% in the control group, while it increased by only 41.85% in the treatment group. Comprehensive analysis of enzyme activity and gene expression revealed that, compared to control, 2-pyrazinecarboxylic acid treatment significantly decreased the activities of key enzymes involved in lignin biosynthesis (POD, F5H, CAD, CCoAOMT, C4H, and 4CL), with average reduction rates of 17.97%, 9.14%, 12.26%, 29.39%, 23.70%, and 27.10%, respectively. Furthermore, the treatment significantly downregulated the expression levels of major coding genes corresponding to these key enzymes (CmPOD3, CmF5H1, CmCAD4, CmCAD5, CmCCoAOMT1, CmCYP73A16, and Cm4CL2). Additionally, compared to control, the treatment remarkably enhanced the contents of glucose, fructose, sucrose, and soluble sugars, with average increase rates of 21.33%, 16.12%, 12.78%, and 5.51%, respectively. Correlation analysis further indicated that lignin content were extremely significantly positively correlated with the activity of its key biosynthetic enzymes, and the increase in lignin content was significantly negatively correlated with the reduction in sugar components.
      Conclusion 2-Pyrazinecarboxylic acid notably suppresses the expression of pivotal enzyme genes involved in lignin biosynthesis, effectively inhibiting enzymatic activity, delaying the lignification process within juice sacs, reducing sugar component depletion, and ultimately preserving the flavor quality of ‘Sanhongmiyou’ pummelo. This research provides a scientific foundation and technical guidance for elucidating the underlying action mechanism of 2-pyrazinecarboxylic acid and enhancing postharvest storage strategies for ‘Sanhongmiyou’ pummelo.

       

      • HTML全文
      • 参考文献(55)
      • 相关文章
      • 施引文献
    • 资源附件(0)

    /

    返回文章
    返回