College of Life Sciences, Inner Mongolia University, Hohhot 010021, PR China.
Plant Physiol Biochem. 2010 Dec;48(12):971-6. doi: 10.1016/j.plaphy.2010.08.009. Epub 2010 Aug 25.
DREB transcription factors play an important role in tolerance to abiotic stress in high plants. In this work, two new DRE-binding protein genes MfDREB1 and MfDREB1s cDNA that encoded an AP2/EREBP type transcription factor were isolated by RT-PCR from Medicago falcate seedlings. Sequence analysis showed MfDREB1 and MfDREB1s were almost identical except that there was a 202bp fragment at the 3' end of the MfDREB1s cDNA that is absent in MfDREB1 cDNA. The MfDREB1 has a open reading frame of 651bp, which encodes 216 amino acid residues. The putative protein is deduced a predicted molecular mass of 24.6kDa and a pI of 5.95. The MfDREB1s has a open reading frame of 555bp, the putative protein is 184 amino acid long with a predicted molecular weight of 20.8kDa, pI 9.11. The Protein Blast data revealed that the two proteins can be classified as a typical member of the AP2/EREBP family of DNA-binding proteins. The comparison of the MfDREB1 cDNA and MfDREB1s cDNA with their corresponding genes in genomic DNA showed that the size and nucleotide sequence of the cDNA was identical to that of the genomic DNA. This suggested that the genomic MfDREB1 gene and MfDREB1s gene had no introns. Southern blot analysis indicated that MfDREB1 and MfDREB1s are multi-copy genes in Medicago falcate genome. Northern blot analysis indicated that the MfDREB1 and MfDREB1s genes were induced by low temperature stress.
DREB 转录因子在高等植物的非生物胁迫耐受中发挥重要作用。本工作采用 RT-PCR 技术从黄花苜蓿幼苗中分离得到两个新的 DRE 结合蛋白基因 MfDREB1 和 MfDREB1s cDNA，它们编码一个 AP2/EREBP 型转录因子。序列分析表明，MfDREB1 和 MfDREB1s 非常相似，除了 MfDREB1s cDNA 的 3'端有一个 202bp 的片段缺失外。MfDREB1 开放阅读框长 651bp，编码 216 个氨基酸残基。推测的蛋白预测分子量为 24.6kDa，等电点为 5.95。MfDREB1s 开放阅读框长 555bp，推测的蛋白长 184 个氨基酸，预测分子量为 20.8kDa，等电点为 9.11。蛋白 Blast 数据显示，这两种蛋白可归类为 DNA 结合蛋白 AP2/EREBP 家族的典型成员。与基因组 DNA 中的相应基因相比，MfDREB1 cDNA 和 MfDREB1s cDNA 的比较表明 cDNA 的大小和核苷酸序列与基因组 DNA 相同。这表明基因组 MfDREB1 基因和 MfDREB1s 基因没有内含子。Southern blot 分析表明，MfDREB1 和 MfDREB1s 是黄花苜蓿基因组中的多拷贝基因。Northern blot 分析表明，MfDREB1 和 MfDREB1s 基因受低温胁迫诱导。
