Isolation and characterization of a differentially expressed sequence tag from Triticum durum salt-stressed roots

Stress responses in plants are important for environmental adaptation and are associated with rapid changes in gene expression. In order to investigate correlations between phenotypic adaptation to stress limitation and induced gene expression, we have studied a model system consisting of a salt-tolerant line (R1) and a salt-sensitive line (S1) of durum wheat (Triticum durum Desf.) subjected to a severe short-term NaCl treatment (200 mM). A mRNA differential display was established for this system to allow the identification of cDNAs induced during salt stress. We cloned and sequenced a cDNA fragment corresponding to a gene that was differentially expressed in salt-stressed (R1) wheat seedlings. Based on the high similarity between the predicted translation product of the cDNA sequence and known members of the dehydrin protein family from wheat (group 2 LEA protein), the cDNA was identified as a member of this gene family. The gene was strongly and rapidly induced in roots and leaves of R1 plants but induction was delayed and transcripts accumulated to a low level in S1 plants.