Huanglongbing pathogen CandidatusLiberibacter asiaticus exploits the energy metabolism and host defence responses of its vector Diaphorina citri

Abstract

AbstractAsian citrus psyllid Diaphorina citri is the vector of the citrus Huanglongbing (HLB) associated bacterial agent ‘Candidatus Liberibacter asiaticus’ (CLas). The molecular interactions between CLas and D. citri remain unclear. In the present study, protein profiles of mitochondrial, microsomal and cytosolic fractions from uninfected and CLas‐infected adult D. citri are investigated using two‐dimensional gel electrophoresis. The comparative analysis reveals a total of 18, 24 and 20 protein spots that are unique or differentially expressed in mitochondrial, microsomal and cytosolic proteins fractions respectively. These proteins are successfully identified by mass spectrometry. Among the 62 identified proteins, 30 are up‐regulated, whereas 32 are down‐regulated. These proteins include important components in energy metabolism such as ATP synthase, ATPase, ATP/ADP carrier protein, etc.; host stress responses such as heat shock proteins; host detoxification processes (i.e., cytochrome P450 and glutathione S‐transferase); and the cytoskeleton (such as actin, tubulin, myosin and tropomyosin). These data suggest that, after CLas infection, several proteins of D. citri, especially energy metabolism and protein biosynthesis, are altered, and extensive host defence responses are induced. In conclusion, the present study reports proteomic information that is helpful in understanding the vector–pathogen relationship between CLas and D. citri, and could be used to identify potential targets for limiting the spread of CLas, as well as to provide new insights into HLB management.