Entomology and Nematology Department, University of Florida, Gainesville, Florida, USA.
Citrus Research and Education Center, University of Florida, IFAS, Lake Alfred, Florida, USA.
Appl Environ Microbiol. 2023 Aug 30;89(8):e0072323. doi: 10.1128/aem.00723-23. Epub 2023 Jul 17.
The Asian citrus psyllid (ACP) Diaphorina citri vectors the causative agent of citrus greening disease that has the capacity to decimate citrus production. As an alternative and more sustainable approach to manage D. citri than repeated application of chemical insecticides, we investigated the potential use of the bacteria-derived pesticidal protein, Mpp51Aa1, when delivered by transgenic Citrus sinensis cv. Valencia sweet orange or Citrus paradisi cv. Duncan grapefruit. Following confirmation of transcription and translation of by transgenic plants, no impact of Mpp51Aa1 expression was seen on D. citri host plant choice between transgenic and control Duncan grapefruit plants. A slight but significant drop in survival of adult psyllids fed on these transgenic plants was noted relative to those fed on control plants. In line with this result, damage to the gut epithelium consistent with that caused by pore-forming proteins was only observed in a minority of adult D. citri fed on the transgenic Duncan grapefruit. However, greater impacts were observed on nymphs than on adults, with a 40% drop in the survival of nymphs fed on transgenic Duncan grapefruit relative to those fed on control plants. For Valencia sweet orange, a 70% decrease in the number of eggs laid by adult D. citri on transgenic plants was noted relative to those on control plants, with a 90% drop in emergence of progeny. These impacts that contrast with those associated with other bacterial pesticidal proteins and the potential for use of Mpp51Aa1-expressing transgenic plants for suppression of D. citri populations are discussed. Pesticidal proteins derived from bacteria such as Bacillus thuringiensis are valuable tools for management of agricultural insect pests and provide a sustainable alternative to the application of chemical insecticides. However, relatively few bacterial pesticidal proteins have been used for suppression of hemipteran or sap-sucking insects such as the Asian citrus psyllid, Diaphorina citri. This insect is particularly important as the vector of the causative agent of citrus greening, or huanglongbing disease, which severely impacts global citrus production. In this study, we investigated the potential of transgenic citrus plants that produce the pesticidal protein Mpp51Aa1. While adult psyllid mortality on transgenic plants was modest, the reduced number of eggs laid by exposed adults and the decreased survival of progeny was such that psyllid populations dropped by more than 90%. These results provide valuable insight for potential deployment of Mpp51Aa1 in combination with other control agents for the management of D. citri.
柑橘木虱（ACP）传播的柑橘黄龙病病原体能够使柑橘产量大幅减少。作为一种替代和更可持续的方法来管理柑橘木虱，而不是反复应用化学杀虫剂，我们研究了转 Citrus sinensis cv. Valencia 甜橙或 Citrus paradisi cv. Duncan 葡萄柚的细菌衍生杀虫蛋白 Mpp51Aa1 的潜在用途。在转基因植物中转录和翻译得到证实后，Mpp51Aa1 的表达对柑橘木虱在转基因 Duncan 葡萄柚和对照 Duncan 葡萄柚植物之间的宿主植物选择没有影响。与对照植物相比，发现喂食这些转基因植物的成年木虱的存活率略有但显著下降。与仅在少数喂食转基因 Duncan 葡萄柚的成年柑橘木虱中观察到的一致，对肠道上皮的损伤与孔形成蛋白引起的损伤一致。然而，在若虫上观察到更大的影响，与对照植物相比，喂食转基因 Duncan 葡萄柚的若虫存活率下降了 40%。对于 Valencia 甜橙，与对照植物相比，喂食转基因植物的成年柑橘木虱产卵数减少了 70%，并且后代的出现率下降了 90%。这些影响与其他细菌杀虫蛋白相关的影响不同，并且 Mpp51Aa1 表达的转基因植物在抑制柑橘木虱种群方面具有潜在的用途。来源于细菌（如苏云金芽孢杆菌）的杀虫蛋白是管理农业害虫的有价值的工具，为应用化学杀虫剂提供了可持续的替代方法。然而，相对较少的细菌杀虫蛋白被用于抑制半翅目或刺吸式昆虫，如柑橘木虱。这种昆虫尤其重要，因为它是柑橘黄龙病病原体的传播媒介，这种病严重影响了全球柑橘生产。在这项研究中，我们研究了生产杀虫蛋白 Mpp51Aa1 的转基因柑橘植物的潜力。虽然转基因植物上的成年木虱死亡率适中，但暴露于杀虫剂的成年木虱产卵量减少，并且后代的存活率降低，导致木虱数量减少了 90%以上。这些结果为 Mpp51Aa1 与其他控制剂结合用于管理柑橘木虱提供了有价值的见解。
