biologia plantarum

Biologia plantarum 55:357-360, 2011 | DOI: 10.1007/s10535-011-0054-2

Overexpression of the Arabidopsis thaliana squalene synthase gene in Withania coagulans hairy root cultures

M. H. Mirjalili¹, E. Moyano², M. Bonfill³, R. M. Cusido³, J. Palazón^3,*

¹ Department of Agriculture, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran

² Departament de Ciencies Experimentals i de la Salut., Universitat Pompeu Fabra, Barcelona, Spain

³ Laboratori de Fisiologia Vegetal, Facultat de Farmacia, Universitat de Barcelona, Barcelona, Spain

Squalene synthase (SS) dimerizes two molecules of farnesyl diphosphate to synthesize squalene, a shared precursor in steroid and triterpenoid biosynthesis in plants. The SS1 gene encoding SS from Arabidopsis thaliana was introduced in Withania coagulans under the control of the CaMV35S promoter together with the T-DNA of Agrobacterium rhizogenes A4. The engineered hairy roots were studied for withanolide production and phytosterol accumulation and the results were compared with those obtained from control roots harbouring only the T-DNA from pRiA4. The increased capacity of the engineered roots for biosynthesizing phytosterols and withanolides was strongly related with the expression level of the transgene, showing the effectiveness of overexpressing 35SS1 to increase triterpenoid biosynthesis.

Keywords: Agrobacterium rhizogenes; phytosterols; Solanaceae; withaferin A; withanolide A

Received: August 8, 2009; Accepted: January 4, 2010; Published: June 1, 2011  Show citation