EN
The expression pattern of a Solanum sogarandinum pGT::Dhn10 gene fusion encoding a dehydrin DHN10 protein and the potential role of that protein in cold tolerance in cucumber were analysed in three T1 transgenic lines. An accumulation of Dhn10 mRNA was detected in the leaves, cotyledons, hypocotyls and roots of the transgenic seedlings both under the control conditions and after a cold treatment at 6oC for 24 h. This was confirmed by RTPCR. However, no DHN10 protein was detected by the alkaline phosphataseconjugated antibody. The transgenic lines exhibited different levels of chilling tolerance. The TCC5/1 line showed a significant increase in its chilling tolerance compared to the non-transgenic line. No chilling injury was observed when the cold hardened (6oC, 24 h) TCC5/1 plants were subsequently exposed to a temperature of 2oC for 6 h. The other two transgenic lines, TCC2/1 and TCC3/2, exhibited a comparable level of chilling tolerance to that of the non-transgenic control. The transgenic lines showed similar or significantly decreased freezing tolerance compared to the non-transgenic control, as evaluated by an electrolyte leakage test. We concluded that the S. sogarandinum GT promoter is functional in the chilling sensitive species Cucumis sativus L., and that the pGT::Dhn10 gene fusion is expressed at the transcriptional level.