Fracarolli Letícia, Rodrigues Gabriela B, Pereira Ana C, Massola Júnior Nelson S, Silva-Junior Geraldo José, Bachmann Luciano, Wainwright Mark, Bastos Jairo Kenupp, Braga Gilberto U L
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
J Photochem Photobiol B. 2016 Sep;162:402-411. doi: 10.1016/j.jphotobiol.2016.07.009. Epub 2016 Jul 9.
The increasing tolerance to currently used fungicides and the need for environmentally friendly antimicrobial approaches have stimulated the development of novel strategies to control plant-pathogenic fungi such as antimicrobial phototreatment (APT). We investigated the in vitro APT of the plant-pathogenic fungus Colletotrichum acutatum with furocoumarins and coumarins and solar radiation. The compounds used were: furocoumarins 8-methoxypsoralen (8-MOP) and 5,8-dimethoxypsoralen (isopimpinellin), coumarins 2H-chromen-2-one (coumarin), 7-hydroxycoumarin, 5,7-dimethoxycoumarin (citropten) and a mixture (3:1) of 7-methoxycoumarin and 5,7-dimethoxycoumarin. APT of conidia with crude extracts from 'Tahiti' acid lime, red and white grapefruit were also performed. Pure compounds were tested at 50μM concentration and mixtures and extracts at 12.5mgL(-1). The C. acutatum conidia suspension with or without the compounds was exposed to solar radiation for 1h. In addition, the effects of APT on the leaves of the plant host Citrus sinensis were determined. APT with 8-MOP was the most effective treatment, killing 100% of the conidia followed by the mixture of two coumarins and isopimpinellin that killed 99% and 64% of the conidia, respectively. APT with the extracts killed from 20% to 70% of the conidia, and the extract from 'Tahiti' lime was the most effective. No damage to sweet orange leaves was observed after APT with any of the compounds or extracts.
对当前使用的杀菌剂的耐受性不断增加以及对环境友好型抗菌方法的需求，刺激了控制植物病原真菌的新策略的发展，如抗菌光处理（APT）。我们研究了用呋喃香豆素、香豆素和太阳辐射对植物病原真菌尖孢炭疽菌进行体外APT。所使用的化合物有：呋喃香豆素8-甲氧基补骨脂素（8-MOP）和5,8-二甲氧基补骨脂素（异茴芹内酯），香豆素2H-色原酮（香豆素）、7-羟基香豆素、5,7-二甲氧基香豆素（柑橘黄酮）以及7-甲氧基香豆素和5,7-二甲氧基香豆素的混合物（3:1）。还对用‘塔希提’酸橙、红葡萄柚和白葡萄柚的粗提物对分生孢子进行APT处理。纯化合物以50μM的浓度进行测试，混合物和提取物以12.5mgL(-1)进行测试。将含有或不含有这些化合物的尖孢炭疽菌分生孢子悬浮液暴露于太阳辐射1小时。此外，还测定了APT对植物寄主甜橙叶片的影响。用8-MOP进行的APT是最有效的处理方法，杀死了100%的分生孢子，其次是两种香豆素的混合物和异茴芹内酯，分别杀死了99%和64%的分生孢子。用提取物进行的APT杀死了20%至70%的分生孢子，‘塔希提’酸橙的提取物最有效。用任何一种化合物或提取物进行APT处理后，未观察到甜橙叶片受到损害。
