Construction of an Infectious DNA Clone of Grapevine Geminivirus A and Its Biological Activity in Nicotiana benthamiana and Grapevine Plants

Abstract

The pathogenicity of grapevine geminivirus A (GGVA), a recently identified DNA virus, to grapevine plants remains largely unclear. Here, we report a new GGVA isolate (named GGVAQN) obtained from grapevine ‘Queen Nina’ plants with severe disease symptoms; the infectious clone of GGVAQN (pXT-GGVAQN) was also constructed. Infection assays indicated that Nicotiana benthamiana plants inoculated with GGVAQN display upward leaf curling and chlorotic mottling symptoms. Direct injection of Agrobacterium tumefaciens cells carrying pXT-GGVAQN into roots of in vitro-grown ‘Red Globe’ grape plantlets by syringe led to systemic infection with GGVAQN, and the plants exhibited chlorotic mottling symptoms on their upper leaves, and downward curling, interveinal yellowing, and leaf-margin necrosis symptoms on their lower leaves. Our results provide insights into the pathogenicity of GGVA, and a simple and efficient inoculation method to deliver infectious viral clones to woody perennial plants.