甘菊DlNAC1转录因子基因提高烟草耐高温能力

研究针对从甘菊中克隆获得的DlNAC1基因（GenBank登录号为EF602305）进行生物信息学分析，并利用根癌农杆菌介导的叶盘转化法将该基因在烟草中进行过表达研究。结果发现DlNAC1蛋白具有较高亲水性，二级结构中占比最高的为无规则卷曲，并具有N糖基化位点等6类潜在的模体结构和典型的由一个扭曲的反平行β片层和α螺旋组成的NAC结构域。将DlNAC1基因在烟草中过表达后，通过PCR方法从55株转化植株中鉴定出36株为阳性植株，并且转基因烟草T₀代植株在45℃高温胁迫后，转35S：DlNAC1基因阳性植株生长状况良好，而对照植株发生萎蔫，并且转基因植株叶片含水量显著高于对照植株。然而，在4℃低温胁迫后，发现转基因烟草T₁代植株没有提高耐低温能力。甘菊DlNAC1基因能够提高烟草植株耐高温能力，为今后菊花抗逆育种提供了科学依据。

Overexpression of DlNAC1 Gene Isolated from Dendranthema lavandulifolium in Enhancing Heat Stress Tolerance in Transgenic Tobacco

We studied the amino sequenceof DlNAC1 gene(GenBank accession number EF602304) cloned from Dendranthema lavandulifolium by bioinformatics methods, and the DlNAC1 gene was transformed tobacco plants by Agrobacterium tumefaciens mediation method. Thepredicted DlNAC1 proteinhad hydrophilicity, and the second structure of this protein was mainly random coil. The NAC protein had six motif models and one NAC domain. The 36 of 55 transgenic tobacco plants were positive by PCR analysis. The heat stress tolerance of PCR positive tobacco plants was increased comparing with the wild plants. With 45℃ treatment for 6 h, the transgenic plants looked much stronger, whereas the wild type looked very weak with wilting leaves. The water content of transgenic plants was more than wild plants. However, the low temperature tolerance of the transgenic plants was not improvedafter 4℃ stress. All these results indicated that DlNAC1 gene improved the tolerance ability to the high temperature stress of transgenic tobacco plants.