College of Plant Health and Medicine, Key Laboratory of Integrated Crop Pest Management of Shandong Province, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, Shandong 266109, China.
Oregon Health & Science University, Portland, OR, USA.
Int J Food Microbiol. 2021 Jan 2;338:108957. doi: 10.1016/j.ijfoodmicro.2020.108957. Epub 2020 Nov 6.
Apple ring rot, caused by Botryosphaeria dothidea, is one of the important diseases in China. This pathogen infects branches and fruit and also results in fruit decay during storage. Biocontrol agents have been proposed to reduce apple decays during storage and are considered as a promising alternative strategy to traditional chemical treatment. In this study, Meyerozyma guilliermondii Y-1, isolated from healthy grape fruit, was firstly evaluated for its biocontrol efficiency against B. dothidea in postharvest apple fruit, and the possible mechanisms were investigated. The results revealed that M. guilliermondii Y-1 treatment effectively reduced apple ring rot caused by B. dothidea in vivo. The disease incidence and lesion diameter were reduced by 32.22% and 57.51% compared with those of control fruit. Furthermore, the use of filtrate and autoclaved culture of M. guilliermondii Y-1 also showed a certain degree of control efficiency against fruit ring rot. M. guilliermondii Y-1 significantly inhibited the mycelial growth and spore generation of B. dothidea in vitro and exhibited an obvious ability to colonize in apple fruit wounds and surface at 25 °C or 4 °C. In addition, M. guilliermondii Y-1 treatment significantly enhanced the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonialyase (PAL), and polyphenoloxidase (PPO), promoted the total phenolics content, and alleviated lipid peroxidation in apple fruit. As expected, we found that the expression of four pathogenesis-related proteins genes (MdPR1, MdPR5, MdGLU, and MdCHI) was remarkably increased by M. guilliermondii Y-1 treatment. Our data together suggest that M. guilliermondii Y-1 is a potential biocontrol agent against B. dothidea postharvest infection in apple fruit, partially through inhibiting mycelial growth and spore germination of B. dothidea, competing for space and nutrient with pathogen, and inducing resistance in apple fruit by stimulating a series of defense responses.
苹果轮纹病由 Botryosphaeria dothidea 引起，是中国的重要病害之一。该病原菌可侵染枝干和果实，导致果实贮藏期腐烂。生物防治剂已被提议用于减少贮藏期间的苹果腐烂，被认为是传统化学处理的有前途的替代策略。在这项研究中，从健康葡萄果实中分离出的酿酒酵母 Y-1 首次被评估用于防治采后苹果果实中的 B. dothidea，同时研究了其可能的作用机制。结果表明，M. guilliermondii Y-1 处理可有效减少活体苹果轮纹病的发生。与对照果实相比，发病率和病斑直径分别降低了 32.22%和 57.51%。此外，M. guilliermondii Y-1 的滤液和高压灭菌培养液也显示出一定程度的防治果实轮纹病的效果。M. guilliermondii Y-1 显著抑制了 B. dothidea 的菌丝生长和孢子产生，在 25°C 或 4°C 时对苹果果实伤口和表面具有明显的定殖能力。此外，M. guilliermondii Y-1 处理显著增强了苹果果实 CAT、SOD、POD、PAL 和 PPO 的活性，促进了总酚含量的增加，并减轻了苹果果实的脂质过氧化作用。正如预期的那样，我们发现 M. guilliermondii Y-1 处理显著增加了四个病程相关蛋白基因（MdPR1、MdPR5、MdGLU 和 MdCHI）的表达。我们的数据表明，M. guilliermondii Y-1 是一种潜在的防治苹果果实采后 B. dothidea 感染的生物防治剂，部分通过抑制 B. dothidea 的菌丝生长和孢子萌发，与病原菌竞争空间和养分，并通过刺激一系列防御反应诱导苹果果实产生抗性。
