Résumé
Climate change is known to cause a number of abiotic stresses affecting plants, including rising temperatures. In some regions of the world, grapevine has already experienced a decline in the quality and yield of grape berries in recent decades. Potassium (K+) is the most abundant cation in plant cells, and it plays a significant role in grapevine growth, as well as in the composition of the grape berry. Its content in berries increases in response to heat. If a high enough temperature is reached, changes in the composition of the berries can be observed, resulting in deleterious impacts on the wine produced and its aging potential. Therefore, it is of interest to better understand the potassium transport pathways in berries, especially in response to heat. Shaker-like potassium channels are known to mediate the majority of K+ fluxes at the plasma membrane. Hence, we decided to focus on identifying potential regulatory partners of these channels. To do this, two cDNA libraries were prepared with RNAs from grape berries at various stages of development and exposed to different temperatures, for two-hybrid and split-ubiquitin screenings. Early results of two-hybrid screenings with Shaker channels as bait show a number of potentially interesting matches, such as a methyltransferase, a kinase and calcium-binding proteins. Preliminary confirmation results are also presented.