The present invention relates to an isolated polynucleotide capable of givinga planttolerance to drought and/or salt stress, which comprises a polynucleotidesequence asshown in SEQ ID NO:1, and to a promoter capable of giving a plant tolerance todroughtand/or salt stress. The present invention also relates to an expression vectorcomprising the said polynucleotide and/or the said promoter, and to a hostcelltransformed or transfected by the said expression vector. The presentinvention furtherrelates to a use of the said polynucleotide or promoter sequence inimprovement ofplant tolerance to drought and/or salt stress.
