Screening And Analysis Of Proteins Interacting With CI In Carica Papaya

Papaya ringspot virus (PRSV, genus Potyvirus, family Potyviridae) is one of the most serious diseases in Carica papaya.The cylidrical inclusion (CI) of potyviruses is required for various steps during plant infection such as genome replication and cell-to-cell movement and has RNAse activities.The multifunction of this protein suggests that a series of compatible interactions with putative host factors are largely unknown. Knowledge about host proteins interacting with CI will help to elucidate the molecular mechanisms of PRSV infection and host defense.In this study,the full-length of PRSV-CI gene was amplified by RT-PCR and bait vetor pSos-CI was obtained which can be used in the Sos Recruitment System (RSR).2 cellular proteins were identified that interacted with PRSV-CI using the RSR search of the Papaya cDNA library. Sequence alignment analysis revealed that one host protein,with high homology to the Elongation factor Tu (EF-Tu) form different plant species, interacted specifically with PRSV-CI. And the interactions between the host proteins and PRSV-CI was retested and confirmed by the Sos Recruitment System.The full-thength cDNA of EF-Tu from Carica papaya was amplified by using bioinformatics combined with genetic technologies such as PCR. Sequence alignment analysis revealed that EF-Tu is highly homologous to the EF-Tu from different plant species. The similar rates of homologous is 70%.The interaction of CI-EF-Tu related to PRSV host range lays a foundation for study of PRSV host range and provides basis for inhibiting or over expressing host factors with mutant key locus by transgenic method, as well as for obtaining virus-resistant plantlets by blocking key factors. Besides, it also provides a research platform for preventing and controlling PRSV. However, it is necessary to verify whether VPg gene is host specific factor of PRSV by other methods.