Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Genetic modification of alternative respiration in Nicotiana benthamiana affects basal and salicylic acid-induced resistance to potato virus X | Lee et al. BMC Plant Biology 2011 11 41 http 1471-2229 11 41 BMC Plant Biology RESEARCH ARTICLE Open Access Genetic modification of alternative respiration in Nicotiana benthamiana affects basal and salicylic acid-induced resistance to potato virus X Wing-Sham l_eeH Shih-Feng FuH Jeanmarie Verchot-Lubicz2 John P Carr1 Abstract Background Salicylic acid SA regulates multiple anti-viral mechanisms including mechanism s that may be negatively regulated by the mitochondrial enzyme alternative oxidase AOX the sole component of the alternative respiratory pathway. However studies of this mechanism can be confounded by SA-mediated induction of RNA-dependent RNA polymerase 1 a component of the antiviral RNA silencing pathway. We made transgenic Nicotiana benthamiana plants in which alternative respiratory pathway capacity was either increased by constitutive expression of AOX or decreased by expression of a dominant-negative mutant protein AOX-E . N. benthamiana was used because it is a natural mutant that does not express a functional RNA-dependent RNA polymerase 1. Results Antimycin A an alternative respiratory pathway inducer and also an inducer of resistance to viruses and SA triggered resistance to tobacco mosaic virus TMV . Resistance to TMV induced by antimycin A but not by SA was inhibited in Aox transgenic plants while SA-induced resistance to this virus appeared to be stronger in Aox-E transgenic plants. These effects which were limited to directly inoculated leaves were not affected by the presence or absence of a transgene constitutively expressing a functional RNA-dependent RNA polymerase MtRDRI . Unexpectedly Aox-transgenic plants infected with potato virus X PVX showed markedly increased susceptibility to systemic disease induction and virus accumulation in inoculated and systemically infected leaves. SA-induced resistance to PVX was compromised in Aox-transgenic plants but plants expressing AOX-E exhibited enhanced SA-induced .
