Expression of β-defensin gene in potato confers enhanced resistance to Ralstonia Solanacearum L.

Abstract

An optimized methodology of Agrobacterium-mediated stable genetic transformation of potato (Solanum tuberosum L.) using the shoot organogenesis potential of internodal stem segments for increased resistance to bacterial plant pathogen, Ralstonia solanacearum L. was developed. Improvised plant regeneration protocol for expression of antimicrobial β-defensin transgene and efficient selection of tissues in plant selectable marker, kanamycin sulphate was successfully utilized for transformation of potato.  Stable integration and expression of antimicrobial peptide was observed in plant tissues and validated by associated molecular analysis by RT PCR, Southern hybridization, northern hybridization and western blotting of the infected tissues. The bacterial wilt disease progression was monitored in controlled greenhouse and Percent Disease Index (PDI) was measured by analysis of variance (ANOVA) that selected superior resistant plants. These transformed plants were able to contain the disease progression and complete the life cycle stages and developed healthy tubers.