Project description:Meristem culture and somatic embryogenesis is an effective tool for virus elimination of vegetatively propagated crops including grapevine. While they both are proved to be useful to eliminate the main grapevine viruses their efficiency differs according to the virus and the variety. In our work we investigated their efficiency using small RNA high-throughput sequencing as virus diagnostic method. Field grown mother plants of four clones representing three cultivars, infected with different viruses and viroids were selected for sanitation via somatic embryogenesis and meristem culture. Our results show that the sanitation with SE was efficient against all of the presenting viruses, including grapevine Pinot gris virus, grapevine rupestris vein feathering virus and grapevine Syrah virus 1, having no data using somatic embryogenesis for their elimination. In case of other viruses and viroids such as GFkV, GRSPaV, GYSVd-1, HSVd this study confirms the findings of earlier researches, that SE is a possible way for elimination. While the efficiency of the elimination of different viruses was high, in case of viroids this ratio was lower. Our work demonstrated that efficiency of SE is comparable to the technically difficult meristem culture technique, and show promising way for the high demand of the production of virus-free grapevine in the future.
2020-12-31 | GSE159758 | GEO
Project description:Diversity genetic of Salmonella Typhimurium isolates in Tunisia
Project description:Grapevine red blotch is a recently identified viral disease that was first recognized in the Napa Valley of California. Infected plants showed foliar symptoms similar to leafroll, another grapevine viral disease, on vines testing negative for known grapevine leafroll-associated virus. Later, the Grapevine red blotch virus (GRBV) was independently discovered in the US states of California and New York and was demonstrated to be the causal agent of red blotch disease. Due to its wide occurrence in the US, vector transmission and impacts on grape industry, this virus has the potential to cause serious economic losses. Despite numerous attempts, it was not possible to isolate or visualize viral particles from GRBV infected plants. Consequently, this has hampered the development of a serological assay that would facilitate GRBV detection in grapevine. We therefore decided to explore mass spectrometry approaches in order to quantify GRBV in infected plants and to identify potential biomarkers for viral infection. We present for the first time the physical detection on the protein level of the two GRBV genes V1 (coat protein) and V2 in grapevine tissue lysates. The GRBV coat protein load in leaf petioles was determined to be in the range of 100 to 900 million copies per milligram wet weight by using three heavy isotope labeled reference peptides as internal standards. The V1 copy number per unit wet tissue weight in leaves appeared to be about six times lower, and about 200-times lower in terms of protein concentration in the extractable protein mass than in petioles. We found a consistent upregulation of several enzymes involved in flavonoid biosynthesis in leaf and petiole extracts of GRBV-infected plants by label-free shotgun proteomics, indicating the activation of a defense mechanism against GRBV, a plant response already described for grapevine leafroll associated virus infection on the transcriptome level. Last but not least, we identified some other microorganisms belonging to the grapevine leaf microbiota, two bacterial species (Novosphingobium sp. Rr 2-17 and Methylobacterium) and one virus, Grapevine rupestris stem pitting associated virus.