Identification of Sugarcane Host Factors Interacting with the 6K2 Protein of the Sugarcane Mosaic Virus

Hai Zhang,Guangyuan Cheng,Jingsheng Xu,Tong Wang,Zongtao Yang

doi:10.3390/ijms20163867

Abstract

The 6K2 protein of potyviruses plays a key role in the viral infection in plants. In the present study, the coding sequence of 6K2 was cloned from Sugarcane mosaic virus (SCMV) strain FZ1 into pBT3-STE to generate the plasmid pBT3-STE-6K2, which was used as bait to screen a cDNA library prepared from sugarcane plants infected with SCMV based on the DUALmembrane system. One hundred and fifty-seven positive colonies were screened and sequenced, and the corresponding full-length genes were cloned from sugarcane cultivar ROC22. Then, 24 genes with annotations were obtained, and the deduced proteins were classified into three groups, in which eight proteins were involved in the stress response, 12 proteins were involved in transport, and four proteins were involved in photosynthesis based on their biological functions. Of the 24 proteins, 20 proteins were verified to interact with SCMV-6K2 by yeast two-hybrid assays. The possible roles of these proteins in SCMV infection on sugarcane are analyzed and discussed. This is the first report on the interaction of SCMV-6K2 with host factors from sugarcane, and will improve knowledge on the mechanism of SCMV infection in sugarcane.

Highlights

Potyviruses, which account for 30% of known plant viruses, include many agriculturally important viruses, e.g., Sugarcane mosaic virus (SCMV), Turnip mosaic virus, Tobacco etch virus, and Potato virus Y [1,2]
20 proteins were identified from sugarcane to interact with SCMV-6K2 by Y2H assay (Table 1) and were classified into three categories based on their functions, i.e., eight proteins in the stress and response group, 12 proteins in the transport group, and four proteins in the photosynthesis group
Since 6K2 is an integral membrane protein and the screening of cDNA library was based on the membrane system, most of the identified proteins are localized to plasma membrane (PM) or the membranes of the chloroplasts, vacuoles, or peroxisomes (Table 1)

Summary

Introduction

Potyviruses, which account for 30% of known plant viruses, include many agriculturally important viruses, e.g., Sugarcane mosaic virus (SCMV), Turnip mosaic virus, Tobacco etch virus, and Potato virus Y [1,2]. In the early stage of potyviral infection, 6K2 localizes to and remodels the endoplasmic reticulum (ER) membrane into convolutional structures, which mature and bud off into vesicles harboring the virus replication complex at ER exit sites in a coatomer protein I (COPI)-dependent and COPII-dependent manner [9,10,11]. These vesicles may fuse with chloroplasts for efficient replication [12]. P3N-PIPO recruits CI to the plasmodesmata [5,10,14,16,17], while CI interacts with 6K2 and serves as a docking point for the

Methods

Results

Conclusion