Cloning Of A AP2/EREBP Transcription Factor Gene From Elytrigia Elongata

Abiotic stresses such as salt,drought,cold and freezing could produce severe damages on growth and development of plants. Genes upregulated upon these stress conditions were basically classified into two groups:those that directly protect against environmental stresses,and those that regulate gene expression and signal transduction upon stress conditions. The first group includes proteins and enzymes that likely function by protecting cells from dehydration,such as late- embryogenesis-abundant (LEA) proteins,enzymes required for biosynthesis of proline,and aquaporins (AQP),et al. The second group of gene products includes transcription factors,protein kinases,and enzymes involved in phosphoinositide metabolism,such as MAP, bZIP, AP2/EREBP. In the past few years,scientists have showed great interest in the second group of genes.In plants,the expression of many genes were regulated at transcriptional level,and mostly it's realized through cis- and trans-acting elements. Therefore,transcription factors could play a key role in stress prevention in plants.In this study, we obtained a AP2/EREBP gene from Elytrigia elongata by RT-PCR using degenerate primers and RACE techonolgy. Through the multiply alignment of amino acid sequences and nucleotide acid sequences of several plant AP2/EREBP in GenBank, a pair of degenerate primers were designed against the conserved regions that was used for RT-PCR to amplify a 117 bp cDNA fragment from Elytrigia elongata. Base on the sequence of the cDNA fragment, primers were designed for 3'RACE and a 1080 bp cDNA fragment was amplified. It was named EeAP2-1,GeneBank Accession No.: EU***005.The amino acid sequence compared by NCBI_Blast revealed high homology with that of other plant EREBP genes, and the similarity to ethylene response factor 2 of Oryza sativa(GeneBank Accession No.:NM₀01069787)was the highest with 77%. Semi-quantitive RT-PCR was performed to reveal transcript level of EeAP2-1 under different abiotic stresses. The results indicated that the mRNA transcription level of EeAP2-1 was up-regulated quickly upon 250 mmol/L NaCl stress and reached its peak after 4 hours, and then decrease, however still maintain a relative high transcription level. The results suggest that EeAP2-1 was involved in responding to salt stress,which may play an important role in salt resistance in Elytrigia elongata. Works on EeAP2-1 responding to other abiotic stress and its plant transformation analysis were carrying on at present.