Abstract A novel endophytic bacterium, designated strain UN1512, was isolated from strawberry leaves, and its antifungal activity against Colletotrichum nymphaeae was estimated under in vitro, in vivo, and greenhouse conditions. The bacterial isolate was identified as Stenotrophomonas maltophilia via morphological, biochemical, and molecular traits. The strain UN1512 decreased the mycelial growth of C. nymphaeae (54.92%) in dual culture. The volatile and non-volatile compounds produced by strain UN1512 reduced mycelial growth of fungal pathogen by 17.85% and 30.06%, respectively. Also, the strain was able to secrete of protease, chitinase, pectinase, siderophore, IAA, and gibberellin. In addition, disease severity of strawberry anthracnose was inhibited via inoculating the bacterial suspension in phylloplane, rhizosphere, and healthy fruits. Also, the effect of volatile compounds (VOCs) produced by strain UN1512 on growth promotion of tomato plants was investigated under in vitro and growth chamber experiments. The results showed that, these compounds significantly enhance the fresh weight and length of roots and shoots. The VOCs produced by strain UN1512 were analyzed by GC-MS and 31 identified VOCs, that Benzothiazole (18.271%), 1,3,5,7-Cyclooctatetraene-1-carboxaldehyde (9.308%), Carbonic acid, octadecyl phenyl ester (5.203%), Benzaldehyde, 2,5-bis[(trimethylsilyl)oxy]- (4.086%), Estragole (3.557%), Benzaldehyde (3.506%) were the major components. Our studies report that strain UN1512 was capable to inhibit the causal agent strawberry anthracnose, and the VOCs produced by this strain increased the tomato seedlings growth.

中文翻译：

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挥发性化合物介导的嗜麦芽窄食单胞菌 UN1512 菌株在植物生长促进中的作用及其对若虫炭疽菌的生物防治潜力

摘要 从草莓叶中分离出一种新的内生细菌，命名为 UN1512 菌株，并在体外、体内和温室条件下评估了其对炭疽病菌的抗真菌活性。该细菌分离物通过形态、生化和分子特征被鉴定为嗜麦芽窄食单胞菌。菌株 UN1512 在双重培养中降低了睡莲 (C. nymphaeae) 的菌丝生长 (54.92%)。UN1512菌株产生的挥发性和非挥发性化合物分别使真菌病原体的菌丝生长减少了17.85%和30.06%。此外，该菌株能够分泌蛋白酶、几丁质酶、果胶酶、铁载体、IAA和赤霉素。此外，通过在叶面、根际和健康果实中接种菌悬液，抑制了草莓炭疽病的严重程度。还，在体外和生长室实验下研究了菌株 UN1512 产生的挥发性化合物 (VOCs) 对番茄植株生长促进的影响。结果表明，这些化合物显着提高了根和芽的鲜重和长度。UN1512菌株产生的VOCs经GC-MS分析，鉴定出31种VOCs，即苯并噻唑（18.271%）、1,3,5,7-环辛四烯-1-甲醛（9.308%）、碳酸、十八烷基苯酯（5.203 %)、苯甲醛、2,5-双[(三甲基甲硅烷基)氧基]-(4.086%)、雌二醇(3.557%)、苯甲醛(3.506%)是主要成分。我们的研究报告称，菌株 UN1512 能够抑制病原体草莓炭疽病，并且该菌株产生的 VOC 促进了番茄幼苗的生长。