Fusarium rot of muskmelon fruit, caused by Fusarium sulphureum, is a typical postharvest decay that not only seriously influences fruit quality but also leads to neosolaniol (NEO) contamination. Therefore, reducing muskmelon postharvest disease and NEO accumulation are of paramount importance. In the present study, the inhibitory effect of acetylsalicylic acid (ASA) against Fusarium rot and NEO accumulation in muskmelon fruits and its potential mechanism of action were investigated. The results indicated that 4 mmol/L ASA effectively inhibited Fusarium rot development and NEO production. Further investigation suggested that the possible mechanism was the activation of polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonialyse (PAL), cinnamate-4-hydroxylase (C4H) and 4-coumarate-CoA ligase (4CL) and their corresponding gene expression, which resulted in the accumulation of total phenols and major synthesis substrates cinnamic acid, p-coumaric acid, caffeic acid, ferulic acid and erucic acid, and in the accumulation of lignin and major synthesis substrates p-coumarin, coniferol and sinadiol involved in phenylpropane metabolism. Moreover, ASA stimulated the expression of the pathogenesis-related proteins chitinase (CHT) and β-1,3-glucanase (GLU). These results suggest that ASA application could inhibit Fusarium rot and NEO accumulation by activating phenylpropane metabolism and pathogenesis-related proteins in inoculated muskmelon fruits.

甜瓜果实镰刀菌腐烂，由硫磺镰刀菌引起，是典型的采后腐烂，不仅严重影响果实品质，而且导致新茄醇 (NEO) 污染。因此，减少甜瓜采后病害和 NEO 积累至关重要。在本研究中，研究了乙酰水杨酸（ASA）对甜瓜果实中镰刀菌腐烂和NEO积累的抑制作用及其潜在作用机制。结果表明，4 mmol/L ASA有效抑制镰刀菌腐烂发展和NEO产生。进一步的研究表明，可能的机制是多酚氧化酶（PPO）、过氧化物酶（POD）、苯丙氨酸氨解酶（PAL）、肉桂酸-4-羟化酶（C4H）和4-香豆酸-CoA连接酶（4CL）及其相应基因的激活。表达，导致总酚和主要合成底物肉桂酸、对香豆酸、咖啡酸、阿魏酸和芥酸的积累，以及参与苯丙烷代谢的木质素和主要合成底物对香豆素、松柏醇和芥子醇的积累. 此外，ASA刺激发病相关蛋白几丁质酶（CHT）和β-1,3-葡聚糖酶（GLU）的表达。这些结果表明，ASA 应用可通过激活接种甜瓜果实中的苯丙烷代谢和发病机制相关蛋白来抑制镰刀菌腐烂和 NEO 积累。ASA刺激发病相关蛋白几丁质酶（CHT）和β-1,3-葡聚糖酶（GLU）的表达。这些结果表明，ASA 应用可通过激活接种甜瓜果实中的苯丙烷代谢和发病机制相关蛋白来抑制镰刀菌腐烂和 NEO 积累。ASA刺激发病相关蛋白几丁质酶（CHT）和β-1,3-葡聚糖酶（GLU）的表达。这些结果表明，ASA 应用可通过激活接种甜瓜果实中的苯丙烷代谢和发病机制相关蛋白来抑制镰刀菌腐烂和 NEO 积累。