《环境昆虫学报》

番茄潜叶蛾Tuta absoluta（Meyrick）主要危害茄科植物，尤其喜食番茄，严重影响番茄产量和品质。昆虫与植物互作通常需要直接的物理接触，唾液在其中扮演着重要角色。唾液细菌作为昆虫唾液的重要组成部分，解析其在昆虫取食寄主植物过程中所发挥的作用具有重要意义。本研究采用传统分离纯化方法对番茄潜叶蛾3龄幼虫唾液中的细菌进行分离，采用16S rRNA序列同源性分析对分离菌株进行了种属鉴定；并将分离菌株接种至番茄植株中，对接种后植株的叶绿素、丙二醛、过氧化物酶、超氧化物歧化酶、可溶性糖、可溶性蛋白、氮和磷元素等生长及防御指标进行测定。结果显示，分离得到的唾液细菌分属3门6属7种，分别为厚壁菌门Firmicutes的蒙氏肠球菌Enterococcus mundtii和解淀粉芽孢杆菌Bacillus amyloliquefaciens，变形菌门Proteobacteria的阴沟肠杆菌Enterobacter cloacae和Acinetobacter rhizosphaerae，放线菌门Acinobacteria的树状微杆菌Microbacterium arborescens、食油微杆菌Microbacterium oleivorans和萎蔫短小杆菌Curtobacterium flaccumfaciens。体外接种试验发现M. arborescens和E. mundtii能够显著降低番茄植株的POD活性，两种菌处理后POD活性分别下降了62.92%、76.83%，且A. rhizosphaerae、E. mundtii处理后的植株丙二醛含量显著上升（P＜0.05）；可溶性蛋白经M. arborescens、E. mundtii和M. oleivorans处理后显著上升（P＜0.05），可溶性糖则在A. rhizosphaerae和E. cloacae处理后显著下降（P＜0.05），氮元素也在唾液细菌处理后总体呈下降趋势；所有处理组相较于对照组的植株叶绿素含量都显著提升（P＜0.05）。综上，番茄植株经番茄潜叶蛾唾液细菌体外接种后发生过氧化反应，且部分菌株使番茄的防御受到抑制，这证明番茄潜叶蛾的唾液参与调控番茄的生长及防御，这可能是番茄潜叶蛾能适应番茄的有利因素之一。该研究丰富了番茄潜叶蛾-番茄互作机制，为防治番茄潜叶蛾提供了理论基础。

英文摘要:

The tomato leaf miner, Tuta absoluta Meyrick (Lepidoptera), primarily attacks Solanaceae species, particularly tomatoes, significantly affecting both yield and quality. Saliva plays a crucial role in insect-plant interactions that often involve direct physical contact. As an important part of insect saliva, it is of significant importance to analyze the role of salivary bacteria in the feeding processes of insects on host plants. In this study, conventional isolation methods were employed to isolate bacteria from the saliva of third-instar larvae of T. absoluta. Species identification of the isolated strains was performed using 16S rRNA sequence homology analysis. The isolated strains were inoculated into tomato plants, and growth and defense indexes, including chlorophyll, malondialdehyde, peroxidase, superoxide dismutase, soluble sugar, soluble protein, nitrogen, and phosphorus were measured following inoculation. The results showed that the isolated salivary bacteria belonged to three phyla, six genera, and seven species: Enterococcus mundtii and Bacillus amyloliquefaciens (phylum Firmicutes), Enterobacter cloacae and Acinetobacter rhizosphaerae (phylum Proteobacteria), Microbacterium arborescens, Microbacterium oleivorans and Curtobacterium flaccumfaciens (phylum Acinobacteria). Inoculation experiments demonstrated that M. arborescens and E. mundtii significantly reduced the peroxidase activity of tomato plants by 62.92% and 76.83%, respectively. Treatments with A. rhizosphaerae and E. mundtii resulted in a significant increase in malondialdehyde content in the plants (P < 0.05). Soluble protein levels increased significantly after treatment with M. arborescens, E. mundtii, and M. oleivorans (P < 0.05), whereas soluble sugar content was significantly lower than that in the control group following treatment with A. rhizosphaerae and E. cloacae (P < 0.05). Nitrogen levels also exhibited a decreasing trend after treatment with the salivary bacteria. Additionally, chlorophyll content was significantly higher in all treatment groups compared to the control group (P < 0.05). In conclusion, inoculation with salivary bacteria from T. absoluta leads to peroxidation in tomato plants, and certain strains inhibit the plants’ defense mechanisms. This finding indicates that the saliva of T. absoluta plays a role in regulating the growth and defense responses of tomato plants, which may facilitate the adaptation of T. absoluta to its host. This study enriches our understanding of the mechanisms underlying the interaction between T. absoluta and tomato plants and provides a theoretical basis for the control of T. absoluta.

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