Cloning and characterization of peanut allene oxide cyclase gene involved in salt-stressed responses.

In this study, the full-length cDNA encoding allene oxide cyclase (AhAOC) was isolated from peanut (Arachis hypogaea L.). The deduced amino acid sequence of AhAOC showed high homology with other plant AOCs. The transcript of AhAOC was found to be abundantly expressed in roots. Expression analysis demonstrated that AhAOC was induced by abscisic acid, methyl-jasmonic acid, salicylic acid, salinity, polyethylene glycol, and cold stresses, particularly by high salinity. Overexpression of AhAOC in rice increased root elongation and plant height compared with expression in control plants and conferred tolerance against salinity. Thus, the AhAOC gene may play an important role in increasing the expression of transcription factors (MYB2 and OsONAC045) and functional genes (DREB1F and LEA3) in transgenic rice under salt stress as well as improve stress tolerance through the accumulation of compatible solutes (proline and soluble sugar). The AhAOC gene is a potential resource for enhancing salt tolerance in crop species.