Role of Phytotoxins in the Pathogenesis of Burkholderia Species

Relationship between phytotoxin production and pathogenicity in Burkholderia spp. was investigated. Tropolone productive strains of B. plantarii and B. vandii were pathogenic to rice seedlings, gladiolus leaves and onion bulbs. Similarly, toxoflavin productivity correlated with pathogenicity of bacterial isolates to all plants used i.e. rice seedlings, dendrobium, cymbidium, gladiolus leaves, potato tubers and onion bulbs in B. glumae and B. gladioli. Treatment of these plants with tropolone caused damages on rice seedlings and onion bulbs, whereas no damage was observed on gladiolus leaves. Toxoflavin treatment gave damages on rice seedlings, leaves of orchidaceous plants, gladiolus and onion bulbs, but no distinct damage was shown on potato tuber. Some unknown factor(s) other than phytotoxin will also be associated with virulence in Burkholderia spp.