Clonagem e caracterização parcial de dois genes de enzimas da via de terpenos em Lippia alba (MILL) N.E. (Verbenaceae)

Abstract

The genus Lippia belongs to Verbenaceae family, Asteridaee, order Lamiales. This family comprises about 175 genus and 2800 species, and many of them have medicals and ornamentals proprierties. Lippia alba is native from South America, and is also found in Brazil and is the most studied species of the genus Lippia. This plant blooms throughout the year and has great importance due to its medicinal properties. The Lippia alba essential oils are composed by sesquiterpenes and monoterpenes conferring its medicinal properties. The aim of this work was to clone and to analize gene expression of putative terpene synthases genes (TPS) in Lippia alba. Alignment of TPS genes was used to design degenerate primers into conserved domains for cloning of these genes in Lippia alba. We have cloned two putative TPS genes, LaTPS12 and LaTPS23. After cloning, semiquantitative RT-PCR was employed to expression analysis of these two genes in different leaf stages and among three different chemotypes of Lippia alba. The result of expression level showed that LaTPS12 occurred at higher level in leaves located in fourth nodal segment and showed a marked differential expression among the chemotypes. The difference of expression of the LaTPS23 was less prominent comparing the three studied chemotypes. We performed a phylogenetic analysis in order to compare the LaTPS12 and LaTPS23 to others TPS genes in different plant species. The results showed that these LaTPS12 and LaTPS23 belong to the class TPS-b, which comprises mainly angiosperms monoterpene synthases genes.