Candidatus Liberibacter asiaticus influences the emergence of the Asian citrus psyllid Diaphorina citri by regulating key cuticular proteins

Abstract The Asian citrus psyllid, Diaphorina citri , is the primary vector of the HLB pathogen, Candidatus Liberibacter asiaticus ( C Las). The acquisition of C Las shortens the developmental period of nymphs, accelerating the emergence into adulthood and thereby facilitating the spread of C Las. Cuticular proteins (CPs) are involved in insect emergence. In this study, we investigated the molecular mechanisms underlying C Las‐promoted emergence in D. citri via CP mediation. Here, a total of 159 CP genes were first identified in the D. citri genome. Chromosomal location analysis revealed an uneven distribution of these CP genes across the 13 D. citri chromosomes. Proteomic analysis identified 54 differentially expressed CPs during D. citri emergence, with 14 CPs exhibiting significant differential expression after C Las acquisition. Five key genes, Dc18aa‐1 , Dc18aa‐2 , DcCPR‐24 , DcCPR‐38 and DcCPR‐58 , were screened from the proteome and C Las acquisition. The silencing of these 5 genes through a modified feeding method significantly reduced the emergence rate and caused various abnormal phenotypes, indicating the crucial role that these genes play in D. citri emergence. This study provides a comprehensive overview of the role of CPs in D. citri and reveals that C Las can influence the emergence process of D. citri by regulating the expression of CPs. These key CPs may serve as potential targets for future research on controlling huanglongbing (HLB) transmission.