Development of a Full-Length Infectious cDNA Clone of the Grapevine Berry Inner Necrosis Virus

Abstract

Grapevine berry inner necrosis virus (GINV) belongs to the genus Trichovirus in the family Betaflexiviridae. The GINV isolate LN_BETA_RS was obtained from a “Beta” grapevine (Vitis riparia × Vitis labrusca) exhibiting chlorotic mottling and ring spot in Xingcheng, Liaoning Province, China. To verify the correlation between GINV and grapevine chlorotic mottling and ring spot disease, we constructed an infectious cDNA clone of GINV isolate LN_BETA_RS using the seamless assembly approach. Applied treatments of agroinfiltration infectious cDNA confirmed systemic GINV infection of the Nicotianaoccidentalis 37B by reverse transcription polymerase chain reaction (RT-PCR) and transmission electron microscopy, exhibiting chlorotic mottling symptoms on leaves. Infectious cDNA was also transmitted to new healthy N. occidentalis plants through rub-inoculation. Moreover, the cDNA clone was agroinfiltrated into “Beta” and “Thompson Seedless” grapevine plantlets, and the inoculated grapevines exhibited leaf chlorotic mottling and ringspot during the two years of observation. GINV-inoculated “Beta” grapevines had serious leaf chlorotic mottling and ringspot symptoms on the whole plant, while relatively few symptoms were observed on the leaves of agroinoculated “Thompson Seedless” grapevines in early spring and only weak ring spot gradually appeared later in the top young leaves. Our experiments fulfilled Koch’s postulates and revealed the causative role of GINV in grapevine chlorotic mottling and ring spot disease.

Construction of an Infectious DNA Clone of Grapevine Geminivirus A Isolate GN and Its Biological Activity in Plants Analyzed Using an Efficient and Simple Inoculation Method

“…One important factor that hinders the research on viruses of woody perennial plants, including grapevine, is the lack of a reliable experimental system for delivering infectious clones. Two main approaches, vacuum-agroinfiltration [ 2 , 9 , 16 ] and agro-drenching [ 10 , 15 , 18 ], are currently used to deliver infectious clones into grapevine plants. However, they are complex and time-consuming, and the achieved rate of infection is relatively low.…”

“…Infectious clones of viruses are important research tools for the analysis of viral biology and pathogenic mechanisms. Infectious clones of some grapevine viruses [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] have already been constructed. By using GGVA infectious clones, the pathogenicity of different GGVA isolates has been analyzed in Nicotiana benthamiana [ 8 , 16 ] and grapevine [ 16 ] plants.…”

“…Plants 2024, 13, 1601 2 of 10 Grapevine and other woody perennials are recalcitrant to mechanical inoculation. The main approaches for delivering infectious clones into grapevine plants include vacuumassisted agroinfiltration [2,9,16] and agro-drenching [10,15,18]. However, these methods are complex and time-consuming, especially for the latter method, which requires more than 20 days to establish a viral infection.…”

Identification and Characterization of a Novel Emaravirus From Grapevine Showing Chlorotic Mottling Symptoms

“…Chlorotic mottling of leaves is a common virus-caused symptom in grapevines in China. Fan and coworkers suggested that GPGV, GINV, and GFabV may cause similar symptoms ( Fan et al, 2020 ). However, we found only GEVA and two viroids in the SJ grapevine having chlorotic-mottling symptoms according to HTS, and not the viruses mentioned above.…”

“…China is one of the world’s leading grape-production areas (estimated recently to cover a total area of 725,100 hectares). Grapevine virus diseases are major threats to grape production, with 21 species of grapevine viruses reported in China ( Fan et al, 2020 ; Ren et al, 2021 ). Chlorotic mottling symptoms caused by viruses on grapevines are common, and have become a major problem in China.…”