Universidade Federal de São Carlos, CEP 13600-970 Araras, SP, Brazil.
Universidade Estadual Paulista "Julio de Mesquita Filho", CEP 4884-900 Jaboticabal, SP, Brazil.
Microbiol Res. 2015 Jun;175:93-9. doi: 10.1016/j.micres.2015.04.003. Epub 2015 Apr 17.
In this study, we evaluated the efficiency of six isolates of Saccharomyces cerevisiae in controlling Colletotrichum acutatum, the causal agent of postbloom fruit drop that occur in pre-harvest citrus. We analyzed the mechanisms of action involved in biological control such as: production of antifungal compounds, nutrient competition, detection of killer activity, and production of hydrolytic enzymes of the isolates of S. cerevisiae on C. acutatum and their efficiency in controlling postbloom fruit drop on detached citrus flowers. Our results showed that all six S. cerevisiae isolates produced antifungal compounds, competed for nutrients, inhibited pathogen germination, and produced killer activity and hydrolytic enzymes when in contact with the fungus wall. The isolates were able to control the disease when detached flowers were artificially inoculated, both preventively and curatively. In this work we identified a novel potential biological control agent for C. acutatum during pre-harvest. This is the first report of yeast efficiency for the biocontrol of postbloom fruit drop, which represents an important contribution to the field of biocontrol of diseases affecting citrus populations worldwide.
在这项研究中，我们评估了六种酿酒酵母（Saccharomyces cerevisiae）分离株控制炭疽病菌（Colletotrichum acutatum）的效率，炭疽病菌是导致柑橘采前果实脱落的病原体。我们分析了生物防治中涉及的作用机制，如：产生抗真菌化合物、营养竞争、检测杀伤活性，以及六种酿酒酵母分离株对炭疽病菌的水解酶的产生及其对离体柑橘花后果实脱落的控制效率。结果表明，所有六种酿酒酵母分离株都产生了抗真菌化合物，与真菌细胞壁接触时会进行营养竞争、抑制病原菌的萌发，并产生杀伤活性和水解酶。当离体花朵被人工接种时，这些分离株可以预防和治疗地控制疾病。在这项工作中，我们鉴定了一种针对采前炭疽病的新型潜在生物防治剂。这是首次报道酵母对采后果实脱落的生物防治效率，这是对全球柑橘种群病害生物防治领域的重要贡献。
