Ginseng γ-thionin is localized to cell wall-bound extracellular spaces and responsive to biotic and abiotic stresses

Abstract: Genomic DNA sequence of a γ-thionin in the Panax ginseng plant, termed Pgγ-thionin, contains 2 exons coding a 225-bp open reading frame with its deduced 75 amino acid sequence interrupted by 1 internal intron. The mRNA transcript level of Pgγ-thionin was ubiquitously expressed in the leaf, flower bud, stem, root and rhizome, with its highest expression in the roots. Pgγ-thionin was responsive to both biotic and abiotic stresses, such as an 18-fold increase after exposure to ABA. Fluorescent tagged-Pgγ-thionin protein was localized to cell wall-bound extracellular spaces. Our finding indicates that Pgγ-thionin might be involved in cellular defense responses. [Copyright &y& Elsevier]