Abstract:Abscisic acid (ABA) regulates the essential physiological and developmental processes of plants and plays imporant roles in plant responses to various environmental stresses. 9-cis-epoxycarotenoid dioxygenase (NCED) is the key regulatory enzyme in the biosynthesis pathway of ABA in higher plants. In the study, a full-lengh cDNA of NCED gene (LbNCED) was fristly isolated and characterized from the leaves of L.barbarum. LbNCED has 2,316 bp, containing a 1,824-bp ORF and encoding 607 amino acids. Comparative and bioinformatics analyses revealed that the homologyamino acida sequence of LbNCED to Lycopersicon esculentum and Solanum tuberosum was 90%. At the N-terminus of the LbNCED located a 15-aa putative chloroplast transit peptide. Southern blot analysis revealed that it was a low-copy gene in the genome of L.barbarum. Real-time Quantitative PCR (RT-QPCR) analysis showed that LbNCED mRNA accumulated most abundantly in leaves. The RT-QPCR analysis revealed that dehydration, salt stress signficantly enhanced LbNCED transcript expression and ABA content accumulation.