Modification of Vacuolar Chitinase and Osmotin cDNAs of Tobacco for Extracellular Secretion and their Cloning with CaMV 35S Promoter

Abstract

Complete coding region clones of basic chitinase and osmotin genes were obtained using PCR from cDNAs previously isolated from tobacco floral bud day 7 (Fb7) explants. These genes code for vacuolar forms of chitinase and osmotin. To secrete their protein products extracellularly, stop codons were introduced into the cDNAs before the vacuolar targetting signal using PCR. Constructs have been made with both, full length cDNAs and truncated cDNAs of chitinase and osmotin for plant transformation in Agrobacterium binary vector pGA 470 in which these cDNAs are under the control of CaMV 35S promoter.