Overexpression of ZmOPR1 in Arabidopsis enhanced the tolerance to osmotic and salt stress during seed germination

12-Oxo-phytodienoic acid reductases (OPRs) are enzymes that catalyze the reduction of double bonds in alpha,beta -unsaturated aldehydes and ketones. In this research, we isolated a full length OPRI cDNA from Zea mays, which was designated as ZmOPR1. Transcriptional profiling indicated that ZmOPR1 was induced by osmotic stress as well as high salt in the roots of maize seedlings, while the induction of the ZmOPR1 was hardly observed in the leaves. In addition, expression analysis results showed that ZmOPR1 had the highest expression during early seed germination. ABA stress also resulted in a massive accummulation of ZmOPR1 transcripts in both the leaves and roots of maize seedlings. To further explore its biological function, we generated transgenic Arabidopsis plants expressing ZmOPR1 under regulation of the cauliflower mosaic virus CaMV 35S promoter. The transgenic plants exhibited an enhanced level of resistance to osmotic and salt stress during seed germination. Further, RNA gel blot analysis revealed that the expression of ZmOPR1 altered the transcription of some abiotic stress-related genes, including RD22, RD29B and ABF2. (c) 2007 Elsevier Ireland Ltd. All rights reserved.