Functional characterization of NtLTP2 in regulating tobacco root development

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 four α-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.