METHOD FOR GENETIC ENGINEERING OF DISEASE RESISTANCE USING THE DR206 CLASS OF PROTEINS

摘要

To identify genes effective against the blackleg fungus Leptosphaeria maculans, we have transformed canola (brassica napus) with four pea (Pisum sativum) genes under constitutive control by the CaMV 35S promoter: PR10.1, chitinase, Drr206 and defensin. Transgenic lines containing single copy T-DNA insertions for each gene were screened for both seedling (cotyledonary) and adult plant resistance. Lines for which pea Drr206 or defensin mRNA was expressed also showed decreased disease scores when inoculated with L. maculans or Sclerotinia sclerotiorum, compared to non-expressing transgenic lines. For PR10 and chitinase transgenics, there was little or no enhancement of resistance. Furthermore, resistance to L. maculans co-segregated with Drr206 and defensin transgenes. Extracts from Drr206 and defensin transgenic plants inhibited fungal growth in-vitro. Drr206 transgenic plants also demonstrated decreased hyphal growth at inoculation sites, and evidence of a hypersensitive response.