Comparative proteomic analysis of Trioza erytreae nymphs developed on Citrus ×limon and Citrus ×sinensis host plants

Abstract Trioza erytreae is a vector of Huanglongbing (HLB), a highly damaging citrus disease. Lemon plants ( Citrus × limon ) are the preferred host for T. erytreae , although the underlying mechanisms behind this remain to be fully elucidated. A comparative proteomic analysis of T. erytreae nymphs in their fourth and fifth instars that were fed either lemon or sweet orange (SwO) was carried out to investigate the interaction with its hosts. A 24-hour sucrose feeding assay was conducted to understand proteomic responses to a nutrient-poor diet. Proteomic profiling using nanoscale liquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS) identified a total of 1,477 psyllid proteins with high confidence. Oviposition and nymphal development were also evaluated across citrus hosts, revealing higher numbers of nymphs developing on lemon than on SwO. Feeding on SwO enriched pathways related to “transmission across chemical synapses” and “metabolism of proteins”. Responses observed under a 24-hour sucrose-only diet enriched the biological processes “response to external stimulus”, “response to stress” and “cytoskeleton organization”. In contrast, these enrichments were absent on lemon host, suggesting that lemon provides a more favourable environment for psyllid development. In addition, nymphs developed on lemon exhibited enhanced energy metabolism and an increase in translation initiation factors. Overall, the results demonstrate that development strongly depends on host plant species, with SwO impairing optimal growth and lemon promoting successful nymphal development.