Relative efficiencies of transient transformation of <em>Arabidopsis thaliana </em> and <em>Nicotianatabacum </em> upon heterologous expression of membrane proteins

Abstract

A cyanobacterial gene encoding a protein with multiple transmembrane helices, when transformed into <em>Arabidopsis thaliana</em> and <em>Nicotianatabacum</em>, demonstrated several differences in the relative responses of both the host species, particularly in efficiencies of regeneration of transformed tissue from leaf explants. The gene of interest (GOI) encoded an integral membrane protein containing 12 transmembrane helices and functioned as a sodium dependent inorganic ion transporter in a native cyanobacterium. <em>Agrobacterium tumefaciens</em>-mediated transformation was carried out by coculture method. The leaves of <em> N. tabacum</em> successfully regenerated into transformed callus tissue and gave positive results upon GUS assay; while the <em>A. thaliana</em> leaves did not give any transformed callus and, a few days post agro-infection, all the explants displayed tissue necrosis. The results obtained point towards <em>A. thaliana's</em> recalcitrance to <em>Agrobacterium</em>-mediated transformation by coculture method and the difficulty of expressing hydrophobic membrane proteins in heterologous systems.