Raspberry ( Rubus idaeus L.) NCED1 gene enhances high salinity and cold tolerance in Arabidopsis

Abscisic acid (ABA) plays an important role in the adaptive response to environmental stress. The rate-limiting step of ABA biosynthesis is the oxidative cleavage of cis-epoxide carotenoid catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED). In this study, the ORF sequence of RiNCED1 in raspberry fruit was isolated to study the function of this gene under abiotic stress. While RiNCED1 was induced by cold, high salinity, heat, and ABA, it highly expressed in new leaves using quantitative real-time PCR. The overexpression of RiNCED1 in Arabidopsis improved the content of ABA in transgenic plants both in high salt and cold conditions. This indicated that overexpressing of RiNCED1 increased the content of ABA in Arabidopsis , which proved that RiNCED1 was involved in ABA biosynthesis. Furthermore, overexpressing of RiNCED1 lead to higher chlorophyll content, higher proline content; higher peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) activities; and lower malondialdehyde (MDA) content under high salt and cold stress. These results indicated that overexpression of RiNCED1 increased the resistance to high salt and low temperature in Arabidopsis . This study provided gene resources for breeding Rubus idaeus L. even other stress-tolerant fruit trees.