Aphid Mouthparts: A Key Target for Plant Protection

Stéphane Blanc of the Institut National de la Recherche Agronomique (INRA) in France will minimize the destructive effects of aphids on crop plants by studying a newly described structure, the acrostyle, which is found at the tip of the piercing mouthparts of the insects and thought to be important for feeding and for transmitting disease-causing viruses between plants. Aphids spread an array of different plant viruses to many crop species including banana, chickpea, and sweet potato. Work during Phase I involved developing tools including acrostyle-targeting antibodies and methods to genetically manipulate aphids, which led to the identification of one protein in the acrostyle that is likely to be a receptor for the cauliflower mosaic virus. Consistent with this, binding of this virus to the insect could be blocked with an antibody targeting that specific protein. In Phase II, they will complete their cataloguing of peptides at the acrostyle using mass spectrometry to identify more candidate receptors that are important for virus binding and transmission, and potentially also for insect feeding. These peptides will be further analyzed using newly developed genetic tools to determine their precise function. They will also use structural methods including nuclear magnetic resonance to identify key amino acid residues in the peptides that could be exploited to block both virus transmission and insect feeding, and thereby weaken the aphids.