SGT1 plays an important role in almost all R gene mediated disease resistance pathways and some non-host disease resistance pathways (Jin et al., 2002; Peart et al., 2002). In order to investigate the possible role of SGT1 in non-host resistance of tobacco plants to P. infestans, we generated transgenic SGT1-silenced tobacco plants (Samsun NN) using RNAi. Twelve transgenic lines with less severe SGT1 silencing phenotype were recovered. Six out of twelve transgenic lines showed clear attenuation of N mediated TMV resistance pathway. Our results showed that the SGT1-silenced tobacco plants were resistant to the three strains of P. infestans, which leads to the conclusion that SGT1 is not involved in the non-host resistance to P. infestans in tobacco or the transgenic plants were only partially silenced and the remaining SGT1 mRNA may be sufficient for resistance to P. infestans.
University of California, Berkeley | Plant & Microbial Biology