Functional properties and expression analysis of squalene synthase candidate gene in different Crown Imperia tissues, during three developmental stages using q-PCR

The genus Fritillaria is recognized as a medicinal and ornamental plant with various pharmaceutical active ingredients, which have been used in traditional medicine. Isosteroidal alkaloids are the major bioactive components in Fritillaria imperialis which include antihypertensive, anticholinergic, antitumour, antiasthmatic and antitussive activities. SQS is a membrane-bound enzyme that plays an important regulatory role in the sterol biosynthetic pathway. In this study, we identified SQS with a key role in the biosynthesis of the Iso steroidal alkaloids by selecting Crown Imperia transcriptome profile. There was high sequence similarity with other flowering plant genes, such as Fritillaria thunbergii, Phoenix dactylifera, Fritillaria unibracteata in the NCBI database using Blastx. The result of alignment with clustal w showed that these sequences were been matched in the conserved region. The results of promoter analysis have shown that it includes responsive elements to light, drought, jasmonic acid, auxin, core promoter element, enhancer and the other elements. The presence of these regulatory elements plays a key role in regulating gene expression in different developmental stages responding to environmental and biosynthesis of secondary metabolites. Finally, expression patterns of SQS in different tissue (leaf, bulb, anther, ovary, sepal, petal and fruit) were assessed in three developmental stages including stem elongation stage, flower development and seed head stage based by qPCR analysis. It suggests that the important role of FiSQS in F.imperialis secondary metabolites biosynthetic. Statistical analysis showed a significant difference for SQS expression level in different tissue and during three developmental stages in, F.imperialis.