Different UV-B Exposure Times Induce Phenotypic, Transcriptomic, and Proteomic Changes in Wine Grape Leaves 

Abstract [Background]The Cabernet Sauvignon grape, considered “the world's most renowned grape variety for the production of fine red wine”, is cultivated in many regions, such as the plateau area in Shangri-La, southwest China. This area is characterized by dry and strong UV climate owing to a high altitude. Previous studies have shown that UV radiation, especially UV-B, improves plant resistance to cold, disease and dry circumstance. In fact, the Cabernet sauvignon, mainly grown in Shangri-La where the UV intensity reaches 21-22w/m2, has shown strong resistance in the past decades. [Aims] However, UV-B’s effect Cabernet Sauvignon grape leaves remains unknown. As a result, we would like to explore the effects of UVB on grape leaves at high altitude through experiments. [Methods]In the present study, we investigated anatomical changes, and photosynthetic changes in Cabernet Sauvignon plants and analyzed transcriptomic and proteomic regulation of these changes following exposure to 15-20w/m2 UV-B for 3 and 7 days. [Results]Results revealed that UV-B exceeding 10w/m2 could change morphology and arrangement of epidermal and palisade tissue cells. We also found upregulation of proteins that regulate cytoskeletal and cell wall synthesis, after 3 days of exposure to UV-B. On the other hand, proteins associated with disease-resistance and antioxidants were up-regulated after 7 days of exposure. Transcriptomic results revealed enrichment of both proteins and genes associated with pathogen infection, defense and antioxidant processes. [Conclusion]As a result, the study showed that strong UV radiation at high altitude did contribute to increased disease resistance and environmental adaptability of grape plants.