Ayoubi Aida, Talebi Ali Asghar, Fathipour Yaghoub, Hoffmann Ary A, Mehrabadi Mohammad
Department of Entomology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
School of BioSciences, Bio21 Institute, University of Melbourne, Parkville, Australia.
Pest Manag Sci. 2025 Aug;81(8):4886-4893. doi: 10.1002/ps.8844. Epub 2025 May 23.
Sap-feeding insects like aphids can harbor a complex of bacterial symbionts, including a primary nutritional symbiont and secondary symbionts that may influence various traits such as resistance to parasitoids and entomopathogens as well as fitness. This study explores the presence and impact of the facultative symbiont, Hamiltonella defensa, in a major pest aphid, the green peach aphid Myzus persicae, focusing particularly on its role in aphid parasitoid resistance, an area that has not been previously characterized.
We detected Buchnera aphidicola and H. defensa endosymbionts in a population of M. persicae collected from Tehran, Iran. Using antibiotic treatments, we mostly removed H. defensa from the aphid and generated a line with only a low level of the symbiont. The parasitism rate of Aphidius matricariae significantly increased in this line compared to untreated controls. Quantitative polymerase chain reaction (qPCR) analysis indicated that the densities of B. aphidicola and H. defensa were affected following parasitism. Twenty-four hours after parasitism, the density of H. defensa and its phage (APSE, Acyrthosiphon pisum secondary endosymbiont) increased compared to the controls, while the density of B. aphidicola decreased. Reverse transcription PCR (RT-qPCR) of APSE encoding toxins revealed high transcription levels of the YDp toxin at 24 h post-parasitism.
These findings indicate that the APSE-3 bacteriophage is present in H. defensa from M. persicae and likely confers parasitoid resistance in this aphid through the YDp toxin. Overall, these results suggest that Hamiltonella can partly protect M. persicae against parasitism. The results have implications for biological control programs targeting this major insect pest. © 2025 Society of Chemical Industry.
像蚜虫这样的吸食汁液昆虫体内可能携带多种细菌共生体，包括一种主要营养共生体和多种次要共生体，这些次要共生体可能会影响各种性状，如对寄生蜂和昆虫病原体的抗性以及适应性。本研究探讨了兼性共生体汉密尔顿氏 defensa 在主要害虫蚜虫——桃蚜（Myzus persicae）中的存在情况及其影响，特别关注其在蚜虫对寄生蜂抗性方面的作用，这一领域此前尚未得到充分研究。
我们在从伊朗德黑兰采集的桃蚜种群中检测到了蚜虫内共生菌（Buchnera aphidicola）和汉密尔顿氏 defensa 内共生体。通过抗生素处理，我们基本清除了蚜虫体内的汉密尔顿氏 defensa，并获得了一个仅含有低水平该共生体的品系。与未处理的对照相比，该品系中豆柄瘤蚜茧蜂（Aphidius matricariae）的寄生率显著增加。定量聚合酶链反应（qPCR）分析表明，寄生后蚜虫内共生菌和汉密尔顿氏 defensa 的密度受到了影响。寄生 24 小时后，与对照相比，汉密尔顿氏 defensa 及其噬菌体（APSE，豌豆蚜次要内共生体）的密度增加，而蚜虫内共生菌的密度降低。对编码毒素的 APSE 进行逆转录 PCR（RT-qPCR）分析发现，寄生后 24 小时 YDp 毒素的转录水平很高。
这些发现表明，APSE - 3 噬菌体存在于桃蚜的汉密尔顿氏 defensa 中，并且可能通过 YDp 毒素赋予该蚜虫对寄生蜂的抗性。总体而言，这些结果表明汉密尔顿氏菌可以部分保护桃蚜免受寄生。这些结果对针对这种主要害虫的生物防治计划具有重要意义。© 2025 化学工业协会。
