Characterization of dehydrin AhDHN from Mediterranean saltbush (Atriplex halimus)

Dehydrins are a group of proteins whose expression is associated with plant abiotic stresses and seed maturation. The full AhDHN dehydrin gene from Mediterranean saltbush (Atriplex halimus) was cloned and characterized. The AhDHN amino acid sequence revealed 1 S-segment, 3 K-segments (K1, K2, K3), and a transmembrane pore-lining signature. It is a 26.77-kDa protein with a predicted isoelectric point of 6.14. Phylogenetic analysis of the AhDHN protein clustered it with other proteins from related plants belonging to the family Amaranthaceae (Atriplex canescens, Spinacia oleracea, Suaeda salsa, and Suaeda glauca). The AhDHN protein sequence revealed a deletion that was 102 amino acids long compared to AcDHN from A. canescens. The expression level of the AhDHN gene was found to be enhanced by salinity stress in Mediterranean saltbush roots but not in shoots. The novel AhDHN gene can be potentially utilized in transformation of other plants to improve tolerance to salinity stress.