1-辛烯-3-醇防治采后桃果实软腐病的作用

Effect of 1-octen-3-ol on soft rot of postharvest peach fruit

摘要:

【目的】桃果实易受匍枝根霉(Rhizopus stolonifer)侵染引起软腐病，导致果实采后腐烂损失严重。目前人工合成的化学杀菌剂是控制桃果实采后病害的主要方法，但长期使用容易带来食品安全隐患、病原菌抗药性和环境污染等问题。通过研究生物源抑菌成分1-辛烯-3-醇对桃果实软腐病的控制作用，为减少化学农药使用和控制采后桃果实软腐病提供理论基础。【方法】使用1-辛烯-3-醇熏蒸接种匍枝根霉(R.stolonifer)后的桃果实，对果实抗病相关基因表达和酶活性进行测定。通过离体试验，研究1-辛烯-3-醇熏蒸对匍枝根霉(R.stolonifer)菌丝和孢子的影响。【结果】55.80μg/mL 1-辛烯-3-醇熏蒸处理可以显著降低桃果实的发病率和病斑直径(P<0.05)，提高几丁质酶(chitinase，CHI)和β-1,3葡聚糖酶(β-1,3-glucanase，GLU)的活性以及病程相关基因非表达子1(nonexpressor of pathogenesis-related protein 1，NPR1)、病程相关蛋白1(pathogenesis-related protein 1,PR1)、CHI和GLU的基因表达量。离体试验结果显示，1-辛烯-3-醇可抑制平板上匍枝根霉(R.stolonifer)菌丝的生长，使菌丝体细胞结构遭到破坏，同时显著降低麦角固醇含量(P<0.05)，抑制孢囊孢子的萌发和芽管伸长，并通过破坏孢子的膜结构，引起活性氧(reactive oxygen species，ROS)暴发与线粒体损伤。【结论】以上结果证实，1-辛烯-3-醇熏蒸处理不仅能直接破坏匍枝根霉(R.stolonifer)的菌丝与孢子，还可通过诱导桃果实的系统获得性抗性(systemic acquired resistance，SAR)抑制采后软腐病的蔓延。

Abstract:

[Objective] Soft rot of postharvest peach fruit, induced by Rhizopus stolonifer, causes huge economic loss. Synthetic fungicides, which are effective for controlling postharvest diseases of peach fruit, pose a threat to food safety, trigger resistance development in the pathogen, and pollute the environment in the instance of long-term use. In this study, we explored the potential inhibitory effect of the biogenic fungicide 1-octen-3-ol on soft rot of peach fruit, hoping to provide an environmentally friendly fungicide for this disease and a reference for the control of soft rot in postharvest peach fruit. [Methods] The peach fruit was fumigated with 1-octen-3-ol after the inoculation with R.stolonifer, and the expression of disease resistance-related genes and activities of related enzymes were determined. The effect of 1-octen-3-ol on the hyphae and spores of R.stolonifer was investigated in vitro. [Results] Fumigation with 1-octen-3-ol at 55.80 μg/mL reduced (P<0.05) the incidence of the disease and lesion diameter and improved the expression of nonexpressor of pathogenesis-related 1 (NPR1), pathogenesis-related protein 1 (PR1), chitinase (CHI), and β-1,3-glucanase (GLU) genes, and the activities of CHI and GLU. The in vitro experiment showed that 1-octen-3-ol could inhibit the growth of R.stolonifer hyphae on the plate and destroy the cell structure of mycelium. Moreover, 1-octen-3-ol could reduce the content of ergosterol in mycelium (P<0.05) and effectively suppress the germination of R.stolonifera sporangiospores and the elongation of germ tubes. It caused reactive oxygen species (ROS) burst and mitochondrial damage by destroying the membrane structure of spores, resulting in apoptosis. [Conclusion] 1-octen-3-ol can not only directly destroy the hyphae and spores of R.stolonifer, but also induce systematic acquired resistance (SAR) of peach fruit to inhibit the spread of postharvest soft rot.