The Application of Quercetin to Study the Effect of Hsp70 Silencing on Plant Virus Infection in Nicotiana benthamiana Plants

Abstract

Pepino mosaic virus (PepMV) is a mechanically-transmitted pathogen affecting tomato plants worldwide. Like with other plant viruses (Verchot, 2012), the heat shock cognate protein 70 homolog (Hsc70) was identified as an interactor of the PepMV coat protein (CP) (Mathioudakis et al., 2012). Here, we describe a pharmacological approach to silence Hsp70 in plants using quercetin (Mathioudakis et al., 2014), an Hsp70 protein expression flavonoid inhibitor (Hosokawa et al., 1990; Manwell and Heikkila 2007). In the case of Hsp70, this methodology represents a faster and easier approach than silencing of Hsp70 by reverse genetics assays, such as VIGS methodology. Fully expanded leaves of 2 to 3 weeks old Nicotiana benthamiana plants were infiltrated, using a syringe, with either quercetin (dissolved in DMSO) or DMSO (control plants). The plants were mechanically inoculated with PepMV virus inocula. The accumulation of Hsp70 and PepMV were analyzed on local leaves by immunoblot analysis 4 days post inoculation.