海洋红冬孢酵母分泌蛋白的鉴定及其在番茄采后生物防治中的应用

以番茄果实为实验试材，选取海洋红冬孢酵母（Rhodosporidium paludigenum）为研究对象，利用Q Exactive UHMR组合型四极杆Orbitrap质谱鉴定并结合生物信息学分析其分泌蛋白组成，探究分泌蛋白在微生物之间以及微生物与番茄之间建立互作关系的功能机制。结果表明，R. paludigenum发酵上清液中含有1 632 条红酵母（Rhodotorula）源特异性目标蛋白质多肽，结合Signal P、WoLF PSORT、Target P、TMHMM、big-PI Predictor和Secretome P等软件分析得到58 个经典分泌特征的蛋白质和433 个非典型分泌特征的蛋白质。蛋白生物学功能结果表明，R. paludigenum分泌蛋白可有效抑制灰葡萄孢菌孢子萌发，抑制率为31.4%，同时有效增强番茄果实伤口处的系统抗病能力，抑制果实伤口处灰霉病发病几率，抑制率达50.1%。结合UniParc数据库信息，发现R. paludigenum分泌蛋白中含有藻胶裂解酶和β-葡萄糖苷酶等18 个碳水化合物酶类蛋白（31.0%），推测可能在R. paludigenum与灰葡萄孢菌的互作和诱导番茄果实系统抗性过程中发挥重要功能，以保护番茄果实免受采后灰霉病害的侵染。

Identification of Secretory Proteins of Rhodosporidium paludigenum and Their Role in Inducing Disease Resistance in Postharvest Tomato Fruits

In order to better understand the functional mechanisms of the secretome of Rhodosporidium paludigenum in its interactions with Botrytis cinerea and tomatoes, Q Exactive UHMR hybrid quadrupole-orbitrap mass spectrometry combined with bioinformatics was employed to identify the unique peptide sequences of the proteins. The results showed that 1 632 unique peptide sequences from Rhodotorula sourced proteins were found in the fermentation supernatant of R. paludigenum, and 58 classical secretory proteins and 433 non-classical secretory proteins were identified using the software SignalP, WoLF PSORT, TargetP, TMHMM, big-PI Predictor and Secretome P. The secretory proteins of R. paludigenum effectively inhibited the spore germination of B. cinerea by 31.4%, and enhanced resistance of tomato fruits to B. cinerea infection around the wound with an inhibition rate of 50.1%. Moreover, based on the UniParc data, 18 (31.0%) carbohydrate-active enzymes such as alginate lyase and β-glucosidase were found in the secretome of R. paludigenum, which may play a vital role in the interaction between R. paludigenum and Botrytis cinerea and in inducing systematic resistance of tomato fruits to gray mold.