Molecular cloning and characterization of a vacuolar Na+/H+ antiporter gene from the succulent xerophyte Zygophyllum xanthoxylum

摘要

Salinity is an environment factor that adversely affects plant growth and development.High salinity causes osmotic and oxidative stresses,and the damage in ion homeostasis.To cope with salt stress, plants have developed a variety of adaptation mechanisms.One of them is to compartmentalize Na＋into the vacuole through the operation of a vacuolar Na+/H+ antiporter (NHX) ( Apse et al.,1999).So far, N H X genes have been isolated from the glycophytes, such as At N H X l in A rabidopsis thaliana,Os N H X l in rice and Gh N H X l in cotton, and the halophytes, such as Ss N H X in Suaeda salsa and Ss N X l in Salicornia europaea.However,N H X genes from the xerophytes have been not reported.In this study, a homologous gene (Zx N H X) of vacuolar Na+/H+ antiporter was cloned and characterized from a typically succulent xerophyte, Zygophyllum xanthoxylum.