Transgenic potatoes expressing wasabi defensin peptide confer partial resistance to gray mold (Botrytis cinerea)

Abstract

Five potato (Solanum tuberosum L.) cultivars were transformed with Agrobacterium tumefaciens strain EHA101 harboring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary plasmid vector, pEKH1. The infected tuber explants co-cultivated for 3 days resulted in higher transformation efficiency (7-50% higher) for all cultivars than 2 days co-cultivation. PCR analysis showed an amplified fragment of wasabi defensin gene and the selectable marker, nptII gene in the genomic DNA of all clones rooted on MS medium supplemented with 100 mgl-1 kanamycin, suggesting their transgenic nature. Southern blot analysis confirmed that transgenic plants integrated 1-6 copies of wasabi defensin gene into their genome. Expression of wasabi defensin protein was confirmed in the leaf extracts of independent transgenic clones by Western blot analysis. Antifungal assay of detached leaves from non-transformed control and transgenic plants indicated that transgenic plants were partially resistant to the fungal pathogen, Botrytis cinerea (gray mold). Copyright © 2006 The Japanese Society for Plant Cell and Molecular Biology.