Differential Expression of Potato Defence Genes Associated with the Salicylic Acid Defence Signalling Pathway in Response to Weakly and Highly Aggressive Isolates of Verticillium dahliae

Abstract

Verticillium wilt is a vascular disease affecting hundreds of important dicotyledonous crops worldwide. Its main causal agent in potato is Verticillium dahliae Kleb. A differential potato‐V. dahliae system consisting of two cultivars of potato (susceptible; S and moderately resistant; MR) and two V. dahliae isolates (weakly, WA and highly aggressive, HA), was used to evaluate the expression of five defence‐related genes, PAL1, PAL2, PR‐1, PR‐2 and PR‐5. These genes were selected because they are in general associated with the salicylic acid defence signalling pathway. Expression levels of these genes were assessed in potato roots and leaves at 0, 4 and 21 h (hpi), and 3, 7 and 14 days postinoculation (dpi). In the roots, the expression of PAL1, PR‐1 and PR‐2 in the MR was higher than in the susceptible cultivar in response to inoculation with either one of the tested V. dahliae isolates. PAL2 gene expression increased gradually starting at 21 hpi in the MR cultivar as opposed to the susceptible one. Higher expression of PR‐1 was detected at 7 dpi in roots. In the leaves, both PAL1 and PAL2 genes showed higher expression in the MR cultivar relative to the susceptible one. Interestingly, the expression of PR‐2 was slightly higher in the susceptible cultivar. Combined data analyses revealed that PAL1, PAL2, PR‐1 and PR‐2 genes are regulated at the transcriptional level in response to infection by V. dahliae. These results indicate that the salicylic acid pathway is also involved in potato defence against V. dahliae and add to the data gathered to elucidate the signalling mechanisms in this host–pathogen interaction.

Suppression subtractive hybridization and comparative expression of a pore-forming toxin and glycosyl hydrolase genes in Rhizoctonia solani during potato sprout infection

“…Generally, studies on differentially expressed genes upon infection of potato with pathogens focus on the host's response (Beyer et al 2001;D'Ippólito et al 2010;Derksen et al 2013;El-Bebany 2010;Gao et al 2013;Gyetvai et al 2012), however, no studies have been done on the down-regulation of fungal genes in these pathosystems. In our study, the high abundance of EST sequences belonging to the delta-endotoxin CytB family prompted us to characterize the corresponding cDNA sequence from R. solani AG-3 Rs114 and study its behavior under different biotic interactions.…”

“…However, the multi-year survival of R. solani in the soil reduces the effectiveness of such practices. Currently, no resistant potato varieties are commercially available, despite global genome sequencing and functional analysis efforts of potato and other pathogens (Beyer et al 2001;Cubeta et al 2014;D'Ippólito et al 2010;Derksen et al 2013;El-Bebany 2010;Gao et al 2013;Gyetvai et al 2012).…”

Long-Term Induction of Defense Gene Expression in Potato by Pseudomonas sp. LBUM223 and Streptomyces scabies

“…or S. scabies and, therefore, there is no information on the signaling mechanisms that may be utilized by potato in such a system. Of the few systemic resistance studies that have been conducted using potato, either ISR or SAR, most have focused on fungal or oomycete pathogens, the majority on P. infestans (12,17,42,43) and Verticillium dahliae (10).…”

Overexpression of StRbohA in Arabidopsis thaliana enhances defence responses against Verticillium dahliae

“…Thus, better understanding of the role of ROS in such mechanisms is an important step towards developing sustainable solutions for verticillium and other wilts. At the transcriptional level, potato defence-related genes responded differentially to highly and weakly aggressive isolates of V. dahliae, including genes from both the salicylate [7] and jasmonate signaling pathways [27]. Along with prior findings on the involvement of StRbohA genes in wound healing, our results prompted us to investigate the use of the latter genes in building plant responses in anticipation of infection by soilborne pathogens such as V. dahliae.…”

“…ROS affect pathogens directly by damaging their cell components and indirectly through activation of host defence mechanisms such as lignin biosynthesis, i.e., incompatible reaction of potato with Phytophthora infestans [3,4], lignification in bean tissues inoculated with Pseudomonas syringae pv. phaseolicola [5], formation of other defence barriers in barley against powdery mildew [6], production of pathogenesis-related proteins and phytoalexins, and a very complex signaling cross-talk [7]. However, many fungi have evolved counter-defence mechanisms to activate stress response regulators thereby tolerating the oxidative stress caused by ROS [8].…”