Genome-wide analysis of OPR family genes in Vitis vinifera and the role of VvOPR1 in copper, zinc tolerance

12-oxo-phytodienoic acid reductase (OPR) is one of the key enzymes in the octadecanoid pathway, and it controls the last step of jasmonic acid (JA) biosynthesis. Although multiple isoforms and functions of <i>OPR</i>s have been identified in various plants, no <i>OPR</i> genes have been identified, and their possible roles in grapevine development and defense mechanisms remain unknown. In this study, nine <i>VvOPR</i> genes were identified from grapevine genome and classified into two subfamilies. Systematic analyses of the physical and chemical properties, the expression and structure of the <i>VvOPR</i> genes, promoter elements, and chromosome locations were performed via bioinformatics and molecular biology methods. In addition, we described the characterization of the <i>OPRI</i> gene <i>VvOPR1</i>, which was synthesized via a PCR-based two-step DNA synthesis quantification reverse-transcription (PTDS) method. <i>VvOPR1</i> expression is tissue-specific and induced by various stresses. The overexpression of <i>VvOPR1</i> in <i>Arabidopsis</i> and rice (OT) significantly increased tolerance to Cu, Zn stress, and Cu, Zn stress-induced restriction of the germination rate, root/shoot length and fresh weight was significantly alleviated in OT. In OT, <i>VvOPR1</i> enhanced the photosynthetic capacity, promoted ABA synthesis and the ABA-dependent stress response pathway, improved the antioxidation capacity by increasing the activities of ROS scavengers and the expression level of the related genes, while enhancing the accumulation of proline, AsA, GSH and reducing MDA and H₂O₂ levels. Moreover, <i>VvOPR1</i> reduced Cu²⁺, Zn²⁺ accumulation and translocation. Together, we first systematically characterized the grapevine OPR gene family and reported that <i>VvOPR1</i> responded to Cu, Zn stress in an ABA-dependent manner, and was quite independent of JA synthesis and signaling. All of the above results provide an important research basis and theoretical basis for further revealing the functions of <i>VvOPR</i> in grapevines in the future.