Guo Long, Mao Xiaoxue, Li Yi, Zhou Zhiqin
College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China; Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing, 400715, China.
College of Horticulture and Landscape Architecture, Southwest University, Chongqing, 400716, China; The Southwest Institute of Fruits Nutrition, Banan District, Chongqing, 400054, China; Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing, 400715, China.
Fungal Biol. 2023 Jan-Feb;127(1-2):854-864. doi: 10.1016/j.funbio.2022.12.003. Epub 2022 Dec 21.
Citrus is susceptible to Penicillium digitatum (P. digitatum) infection in post-harvest storage, resulting in enormous economic losses. This study aimed to investigate the antifungal activity and potential mechanism of the combination of Polymethoxylated flavones (PMFs) and citral (two natural antifungal components derived from citrus) against P. digitatum in vitro and citrus fruit. The results show that PMFs can enhance the antifungal activity of citral nanoemulsion, and PMFs-loaded citral nanoemulsion (PCT) has significant antifungal activity in a concentration-dependent manner. PCT can evidently inhibit spore germination and mycelial growth in vitro, and effectively control the growth of green mold on postharvest citrus fruit. Furthermore, PCT treatment resulted in the alteration of mycelia morphology, accumulation of reactive oxygen species, and membrane lipid peroxidation. These changes can disrupt the normal structure and function of the cell membrane, as evidenced by the reduction of total lipid and ergosterol content in the mycelia and the stronger red fluorescence of the cells emitted after PI staining. Based on the above results, we infer that PCT has a strong inhibitory effect on P. digitatum, and its potential mechanism is related to the destruction of the cell membrane. Therefore, PCT can be considered as a botanical fungicide for citrus preservation.
柑橘在采后贮藏期间易受指状青霉感染，导致巨大的经济损失。本研究旨在探究聚甲氧基黄酮（PMFs）和柠檬醛（两种源自柑橘的天然抗真菌成分）组合对指状青霉的体外抗真菌活性及其潜在机制，并研究其对柑橘果实的影响。结果表明，PMFs可增强柠檬醛纳米乳液的抗真菌活性，负载PMFs的柠檬醛纳米乳液（PCT）具有显著的浓度依赖性抗真菌活性。PCT能明显抑制体外孢子萌发和菌丝生长，并有效控制采后柑橘果实上青霉的生长。此外，PCT处理导致菌丝形态改变、活性氧积累和膜脂过氧化。这些变化会破坏细胞膜的正常结构和功能，菌丝体中总脂质和麦角固醇含量的降低以及PI染色后细胞发出更强的红色荧光证明了这一点。基于上述结果，我们推断PCT对指状青霉有很强的抑制作用，其潜在机制与细胞膜的破坏有关。因此，PCT可被视为一种用于柑橘保鲜的植物源杀菌剂。
