Dhakshinamoorthy Durgadevi, Sundaresan Srivignesh, Iyadurai Arumukapravin, Subramanian Kizhaeral Sevathapandian, Janavi Gnanaguru Janaki, Paliyath Gopinathan, Subramanian Jayasankar
Department of Nano Science & Technology, Tamil Nadu Agricultural University, Coimbatore 641003, India.
Plant Agriculture, University of Guelph, Guelph, ON LOR 2EO, Canada.
Plant Pathol J. 2020 Apr 1;36(2):133-147. doi: 10.5423/PPJ.OA.03.2019.0072.
Hexanal, a C-6 aldehyde has been implicated to have antimicrobial properties. Hence, this study was conducted to determine the antifungal activities of hexanal vapor against major postharvest pathogens of banana ., and . The pathogens were cultured and exposed to hexanal vapor at 600, 800, 1,000 and 1,200 ppm. Mycelial growth of both fungal pathogens were inhibited completely at 800 ppm and the incidence of anthracnose and stem-end rot diseases reduced by 75.2% and 80.2%, respectively. The activities of peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase and glucanase had transiently increased in hexanal vapor treated banana by 5 to 7 days and declined thereafter. Postharvest treatment of banana with hexanal vapor resulted in phospholipase D inhibition and also resulted in cell wall thickening of the treated fruit, which impeded the penetration of the pathogenic spores. This was further confirmed by scanning electron micrographs. The defense-related protein intermediaries had increased in hexanal vapor treated banana fruit, which suggests induced resistance against and , via., the phenylpropanoid pathway which plays a significant role in hindering the pathogen quiescence. Delayed ripening due to inhibition of phospholipase D enzyme, inhibition of mycelial growth and induced systemic resistance by defense enzymes collectively contributed to the postharvest disease reduction and extended shelf life of fruit.
己醛，一种C-6醛类物质，被认为具有抗菌特性。因此，本研究旨在测定己醛蒸汽对香蕉主要采后病原菌（ 、 和 ）的抗真菌活性。将病原菌进行培养，并暴露于浓度为600、800、1000和1200 ppm的己醛蒸汽中。在800 ppm时，两种真菌病原菌的菌丝生长均被完全抑制，炭疽病和蒂腐病的发病率分别降低了75.2%和80.2%。在己醛蒸汽处理的香蕉中，过氧化物酶、多酚氧化酶、苯丙氨酸解氨酶和葡聚糖酶的活性在5至7天内短暂升高，之后下降。用己醛蒸汽对香蕉进行采后处理导致磷脂酶D受到抑制，还使处理后的果实细胞壁增厚，这阻碍了病原菌孢子的侵入。扫描电子显微镜照片进一步证实了这一点。在己醛蒸汽处理的香蕉果实中，与防御相关的蛋白质中介物有所增加，这表明通过在阻碍病原菌静止方面起重要作用的苯丙烷类途径，诱导了对 和 的抗性。由于磷脂酶D酶的抑制、菌丝生长的抑制以及防御酶诱导的系统抗性导致的延迟成熟，共同促成了采后病害的减少和果实货架期的延长。
