the invention discloses maize bzip transcriptional factors , namely , abp2 , abp4 and abp9 , the genes encoding these factors , and the use thereof . the transcriptional factors are proteins having an amino acid sequence set forth in seq id no : 2 , 4 , or 6 , or proteins derived therefrom by substitution , deletion or addition of one or more amino acid residues of seq id no : 2 , 4 , or 6 , and having the same activity as a protein shown by seq id no : 2 , 4 , or 6 . the abp2 , abp4 and abp9 genes encoding these factors , respectively , are the dna sequences having an identity of more than 90 % with a sequence shown by seq id no : 1 , 3 or 5 and the encoded proteins having such same functions . these genes are important for breeding plant varieties with an enhanced tolerance to abiotic stresses and for improving plant tolerance to abiotic stresses .