NtLTP2基因在烟草根系发育中的功能分析

Functional characterization of NtLTP2 in regulating tobacco root development

为阐明烟草NtLTP2基因在烟草生长发育中的功能,以云烟87为试验材料,克隆了NtLTP2基因的编码区和启动子序列,分别对其进行生物信息学预测、启动子组织驱动特性分析,以及基因功能研究。结果表明NtLTP2基因编码区全长294 bp,编码97个氨基酸;NtLTP2具备nsLTP2和AAI-LTSS超家族保守域,蛋白质三级结构包含1个由4个α-螺旋组成的脂质疏水腔。烟草NtLTP2为根部优势表达基因,其启动子能够驱动下游基因在烟草根部特异表达。NtLTP2过表达烟草株系的侧根数目约为对照的2倍,根系的总长、总表面积和总体积均显著增加,并且地上部分的生长发育明显优于对照。

To characterize the function of NtLTP2 gene in the growth and development of tobacco,the coding region and promoter sequence of NtLTP2 were cloned from flue-cured tobacco cultivar Yunyan 87(Nicotiana tabacum).Bioinformatics prediction,promoter tissue driving ability and gene function of NtLTP2 were investigated.Bioinformatic prediction indicated that the coding region of NtLTP2 was 294 bp encoding 97 amino acids.The NtLTP2 protein contained conserved domains of nsLTP2 and AAI-LTSS superfamilies,and the tertiary structure of NtLTP2 had a lipid hydrophobic cavity consisting of fourα-helices.Tissue expression analysis showed that NtLTP2 was a dominant root expression gene,and the NtLTP2 promoter could drive the specific expression of downstream genes in tobacco roots.Gene function analysis indicated that the number of lateral roots of NtLTP2 overexpression lines was about twice that of the control,thus the total length,total surface area and total volume of plant roots were significantly increased.The growth and development of the aerial part were also significantly better than those of the control.