2 research outputs found
Recommended from our members
A Putative PAMP-Induced Peptide Family Member is Associated with Symptom Severity to the Necrotic Strain NTN of Potato Virus Y in Potato
Potato Virus Y (PVY) is an enduring problem for potato production worldwide. Potato varieties that resist the “ordinary” strain PVYO were developed by breeders, but in recent years, recombinant strains of PVY have been able to circumvent this strain-specific resistance and evade growers and seed certification officials by causing fewer symptoms in their hosts. Today, PVYO has been largely replaced by recombinant strains such as PVYN-Wilga and PVYNTN in growers’ fields. Previous transcriptomic analyses in our lab identified the gene PGSC0003DMG400014879 as the most differentially expressed gene in the early stages of the incompatible reaction between potato cv. Premier Russet and PVYO, suggesting that this gene may play an important role in the interaction between potato and PVY. The goal of this thesis was to characterize the function(s) of this gene. Although annotated as an ABC protein in public databases, PGSC0003DMG400014879 encodes an 88 amino acid peptide with a putative signal peptide for targeting to the secretory pathway. Phylogenetic analysis showed that this peptide is closely related to the PAMP-Induced Peptide (PIP) family of immune-modulatory peptides in Arabidopsis, thus we gave it the name StPIP1. To understand the function of this peptide, we analyzed the response of Premier Russet plants that overexpress or silence StPIP1 to three strains of PVY, PVYO, PVYN-Wilga, and PVYNTN. Premier Russet plants produced a hypersensitive response (HR) upon inoculation with PVYO or PVYN-Wilga, but there was no difference in intensity and onset of HR between plants overexpressing or silencing StPIP1 and control plants. In addition, similar to control plants, Premier Russet overexpressing or silencing StPIP1 produced no or very mild symptoms on non-inoculated leaves infected with PVYO or PVYN-Wilga. However, when infected with PVYNTN, Premier Russet plants overexpressing StPIP1 displayed clearly visible rugose mosaic symptoms starting at ~30 dpi, while Premier Russet control and silencing plants were asymptomic at the same time point. QuantSeq analysis showed that the symptoms observed in PVYNTN-infected leaves of StPIP1-overexpressing plants were associated with major changes in gene expression, many of them related to plant defense pathways like the PAMP-Triggered Immunity pathway. activation of plant defenses in StPIP1-overexpressing plants was not sufficient to prevent systemic infection. Several genes encoding leucine-rich repeat-containing receptor-like kinases were strongly induced in StPIP1-overexpressing plants infected with PVYNTN, representing candidate receptors of StPIP1. This work demonstrates that StPIP1 plays an important role in the interactions between potato and PVYNTN, and furthers our understanding of the molecular mechanisms associated with PVY symptoms. We discuss the potential practical applications of these findings for helping potato growers and seed certification officials to identify and rogue PVY-infected plants that would not otherwise show symptoms
Recommended from our members
StPIP1, a PAMP-induced peptide in potato, elicits plant defenses and is associated with disease symptom severity in a compatible interaction with potato virus Y
The role of small secreted peptides in plant defense responses to viruses has been seldom investigated. Here, we report a role for potato (Solanum tuberosum) PIP1, a gene predicted to encode a member of the PAMP-induced peptide (PIP) family, in the response of potato to potato virus Y infection (PVY). We show that exogenous application of synthetic StPIP1 to potato leaves and nodes increased the production of reactive oxygen species and the expression of plant defense-related genes, showing that StPIP1 triggers early defense responses. In support of this hypothesis, transgenic potato plants that constitutively overexpress StPIP1 had higher levels of leaf callose deposition, and based on measurements of viral RNA titers, were less susceptible to infection by a compatible PVY strain. Interestingly, systemic infection of StPIP1-overexpressing lines with PVY resulted in clear rugose mosaic symptoms that were absent or very mild in infected non-transgenic plants. A transcriptomics analysis revealed that marker genes associated with both pattern-triggered immunity and effector-triggered immunity were induced in infected StPIP1-overexpressors but not in non-transgenic plants. Together, our results reveal a role for StPIP1 in eliciting plant defense responses and in regulating plant anti-viral immunity