A full length dehydrin cDNA clone was obtained from a Pistacia vera L. cDNA library. It was sequenced and the deduced protein consisted of 230 amino acids with a molecular weight of 25,870 kDa. The protein is glycine rich and highly hydrophilic and contains 47.39% charged amino acids. It contains 5 repeats of the characteristic K-box, but no serine tract and no Y segment, characteristic of certain dehydrins. The transcript consisted of additional 5 repetitive sequences, 20-22 nucleotides long, on the N-terminus side of the K-box and adjacent to it. A similar pattern of repetitive units was also detected in other dehydrins of deciduous trees, as well as other dehydrins which belong to the Kn-type. Accumulation of the dehydrin transcripts precedes the accumulation of the protein, which stays high in the inflorescence bud throughout winter. The protein accumulates in the outer leaves (scales) of the inflorescence bud and in the bark. It was mostly concentrated in the palisade-like cells underneath the epidermis. It appears like a cytoplasmic protein with no specific organelar location. It was suggested that the inflorescence bud protein (Ibp) dehydrin of pistachio may have a dual purpose, in cold tolerance and in winter storage of nitrogen and carbon for spring growth.

Key words: dehydration stress, dehydrin, dormancy, pistachio Pistacia vera L.