Culturable leaf-associated bacteria on tomato plants and their potential as biological control agents
Culturable leaf-associated bacteria on tomato plants and their potential as biological control agents
复制标题
DOI：
10.1007/s00248-006-9085-1
复制
发表时间：
2007-05-01
影响因子：
3.6
通讯作者：
Tsushima, Seiya
中科院分区：
文献类型：
--
作者：
Enya, Junichiro;Shinohara, Hirosuke;Tsushima, Seiya
可培养的植物叶缘细菌因其能在植物上存活而被认为是有希望的生物防治剂候选者。我们研究了温室和田间番茄叶片上可培养的叶相关细菌的细菌群与其对番茄病害的体外和体内抗真菌活性之间的关系。此外，分析了分离的细菌的N-酰基-高丝氨酸内酯（阿勒）和吲哚-3-乙酸（IAA）的生产，这已被报道与细菌定植，和耐番茄生物碱（α-番茄碱）。叶洗涤液和随后的叶浸渍液用于估计附生细菌和更多内部细菌的种群大小。在温室和田间条件下，同一部位叶片上的细菌数量随着叶片的老化而增加。田间种植的番茄的种群规模明显大于温室种植的番茄。16 S rRNA基因（rDNA）测序使用887可培养的叶相关细菌的分析揭示了优势的芽孢杆菌和假单胞菌可培养的叶相关细菌组温室和田间生长的番茄，分别。从这两个地点经常回收到短杆菌和鞘氨醇单胞菌。从2138个供试菌株中筛选出几个对番茄灰霉病菌、番茄叶霉病菌和番茄早疫病菌具有体外抗真菌活性的菌株。在具有较强体外抗真菌活性的菌株中，芽孢杆菌属和泛菌属倾向于显示出较强的抗真菌活性，而短小杆菌属和鞘氨醇单胞菌属则不有效。结果表明，不同优势菌群的抗真菌活性存在差异。α-番茄碱抗性分析表明，大多数细菌菌株的优势群体表现出中度或高度的生长培养基中的α-番茄碱的电阻。此外，一些鞘氨醇单胞菌和泛菌菌株显示阿勒和IAA的生产活动。125 NP 12（Pantoea ananatis）对α-番茄碱表现出较强的抗性，其阿勒和IAA产量对灰霉病的保护值最高（91.7）。因此，这些生理特性的优势菌之间的差异可能与BCAs对番茄植株的抑病能力有关。
Culturable leaf-associated bacteria inhabiting a plant have been considered as promising biological control agent (BCA) candidates because they can survive on the plant. We investigated the relationship between bacterial groups of culturable leaf-associated bacteria on greenhouse- and field-grown tomato leaves and their antifungal activities against tomato diseases in vitro and in vivo. In addition, the isolated bacteria were analyzed for N-acyl-homoserine lactone (AHL) and indole-3-acetic acid (IAA) production, which have been reported to associate with bacterial colonization, and resistance to a tomato alkaloid (alpha-tomatine). Leaf washings and subsequent leaf macerates were used to estimate the population size of epiphytic and more internal bacteria. Bacterial population sizes on leaves at the same position increased as the leaves aged under both greenhouse and field conditions. Field-grown tomatoes had significantly larger population sizes than greenhouse-grown tomatoes. Analysis of 16S rRNA gene (rDNA) sequencing using 887 culturable leaf-associated bacteria revealed a predominance of the Bacillus and Pseudomonas culturable leaf-associated bacterial groups on greenhouse- and field-grown tomatoes, respectively. Curtobacterium and Sphingomonas were frequently recovered from both locations. From the 2138 bacterial strains tested, we selected several strains having in vitro antifungal activity against three fungal pathogens of tomato: Botrytis cinerea, Fulvia fulva, and Alternaria solani. Among bacterial strains with strong in vitro antifungal activities, Bacillus and Pantoea tended to show strong antifungal activities, whereas Curtobacterium and Sphingomonas were not effective. The results indicated the differences in antifungal activity among predominant bacterial groups. Analysis of alpha-tomatine resistance revealed that most bacterial strains in the dominant groups exhibited moderate or high resistance to alpha-tomatine in growth medium. Furthermore, some Sphingomonas and Pantoea strains showed AHL and IAA production activities. Strain 125NP12 (Pantoea ananatis) showed particular alpha-tomatine resistance, and AHL and IAA production had the highest protective value (91.7) against gray mold. Thus, the differences of these physiological properties among dominant bacteria may be associated with the disease suppression ability of BCAs on tomato plants.