Expressions of Transcription Factor Genes in WRKY Family and Their Target Genes during Dedifferentiation of Mature Wheat (Triticum aestivum L.) Embryos

The expression profiles of transcription factor genes in WRKY family and their target genes were analyzed using Affymetrix wheat GeneChip in this study during dedifferentiation of mature wheat (Triticum aestivum) embryos which cultured on MS medium supplemented with 2,4-D (2 mg·L-1) at different time points of 2, 6, 12, 24 and 72 h. The information was processed using bioinformatics tools at NCBI, DATF, and DRTF websites. The result showed that there were 20 transcription factor genes in WRKY family and their target genes changed significantly in upor down-regulation ranged 2–40 or 2–16 times at least one time point in mature wheat embryos dedifferentiation. According to the known functions of WRKY transcription factors and their changed trend, it was predicted that these genes, especially, WRKY6, WRKY18 and WRKY33 and their target genes CA692019, CA660172 and CA640435, might play roles in dedifferentiation of mature wheat embryos. WRKY6 was down-regulation in dedifferentiation and this indicted that 2,4-D might induce the low tolerance of mature wheat embryos to the stress of environment and thus facilitate the initial of dedifferentiation and its proceeding. WRKY33 might play a role in signal transduction in the early dedifferentiation stage. The different expressions of transcription factor genes in tissue and organ in different species implied the diversity and complex in dedifferentiation mechanism.