Abstract
Cold stress adversely impacts grape growth, development, and yield. Therefore, improving the cold tolerance of grape is an urgent task of grape breeding. The Jasmonic acid (JA) pathway responsive gene JAZ plays a key role in plant response to cold stress. However, the role of JAZ in response to low temperatures in grape is unclear. In this study, VvJAZ13 was cloned from the 'Pinot Noir' (Vitis vinefera cv. 'Pinot Noir') grape, and the potential interacting protein of VvJAZ13 was screened by yeast two-hybrid (Y2H). The function of VvJAZ13 under low temperature stress was verified by genetic transformation. Subcellular localization showed that the gene was mainly expressed in cytoplasm and the nucleus. Y2H indicated that VvF-box, VvTIFY5A, VvTIFY9, Vvbch1, and VvAGD13 may be potential interacting proteins of VvJAZ13. The results of transient transformation of grape leaves showed that VvJAZ13 improved photosynthetic capacity and reduced cell damage by increasing maximum photosynthetic efficiency of photosystem II (Fv/Fm), reducing relative electrolyte leakage (REL) and malondialdehyde (MDA), and increasing proline content in overexpressed lines (OEs), which played an active role in cold resistance. Through the overexpression of VvJAZ13 in Arabidopsis thaliana and grape calli, the results showed that compared with wild type (WT), transgenic lines had higher antioxidant enzyme activity and proline content, lower REL, MDA, and hydrogen peroxide (H(2)O(2)) content, and an improved ability of scavenging reactive oxygen species. In addition, the expression levels of CBF1-2 and ICE1 genes related to cold response were up-regulated in transgenic lines. To sum up, VvJAZ13 is actively involved in the cold tolerance of Arabidopsis and grape, and has the potential to be a candidate gene for improving plant cold tolerance.