The Study Of Host Factors In Nicotiana Benthamiana Response To TYLCV Infection Through ITRAQ Technology

Tomato yellow leaf curl virus(TYLCV)is a type member of the genus Begomoverus in the family Geminiviridae,and is transmitted by Bemisia tabaci.The disease caused by TYLCV has been spreading to the most parts of the world and causing serious losses in tomato production.Therefore,identifying the plant host factors response to TYLCV infection and undersdanding the mechanism for interaction between TYLCV and host plants will provide a theoretical basis on preventing tomato for infection by tomato yellow leaf curl virus.Isobaric tags for relative and absolute quantitation(iTRAQ),as a proteomics technology with advantage of high precision,sensitivity and repeatability,has been widely used in the biological field.In this study,we applied the iTRAQ to investigate the response of Nicotiana benthamiana to TYLCV infection.183 differentially expressed proteins were identified,and among them,the accumulation levels of 100 proteins were increased,whereas 83 proteins were decreased.We choose ten proteins from those differentially expressed proteins to analyze the relationship between transcriptional response and protein accumulation.The results revealed,five proteins showed the same response mode,three proteins had no significant changes in transcriptional response while protein accumulations were increased,and two proteins displayed opposite results in transcriptional response and protein accumulation.We found that the differential expressed proteins were mainly concentrated in energy,defense,protein synthesis or modification and signal transduction pathways.We conducted virus-induced gene silencing(VIGS)to down-regulate the expression levels of some differential expressed proteins,and found that the plants leaves inoculatepd by TYLCV became more yellowing and virus accumulation also increased in system leaves at 28 days after silencing cystein protease inhibitor gene(NbCPI).We infer that NbCPI could be one of the host factors which negatively regulates the TYLCV infection in Nicotiana benthamiana.The subcellular localization analysis showed that NbCPI localized on plasma membrance.Bimolecular fluorescence complementation assay(BiFC)indicated NbCPI can interact with TYLCV encoded proteins C1,C2 and C3.In general,the currently experiment results show that NbCP1 negatively regulates the infection of TYLCV in Nicotiana benthamiana,,but the infection mechanism still needs further investigation.