Improved zinc tolerance of tobacco by transgenic expression of an allene oxide synthase gene from hexaploid wheat

Allene oxide synthase (AOS, EC 4.2.1.92) is the first specific jasmonate biosynthetic pathway gene. In this study, a full-length cDNA of AOS gene was cloned from common wheat nannong 9918. The gene contains an open reading frame (1,446 bp) encoding 418 amino acids. Comparative and bioinformatic analysis revealed that the deduced protein of TaAOS was highly homologous to AOSs from other plant species. The transcript of TaAOS was found to be abundantly expressed in the flag leaves, and was up-regulated by the inoculation of B. Graminis (DC.) E.O. Speer f. sp. Tritici (Bgt) in wheat leaves. In addition, it was also induced by high concentration of NaCl and ZnCl2. When TaAOS was overexpressed in tobacco leaves via Agrobacterium tumefaciens infection, the transgenic tobacco plants displayed stronger tolerance to ZnCl2 stress compared to transgenic GFP plants. Taken together, the above facts demonstrated that TaAOS may play a role in response to diverse stresses in plants.