Pathogenesis Related Protein 5 Expression is Induced by 1,4‐dimethylnaphthalene treatment of Potato Meristems

Abstract

The agricultural compound 1,4‐dimethyl naphthalene (DMN) can be used to inhibit sprouting and prolong the storage of Solanum tuberosum. Potatoes treated with DMN exhibit characteristics that enable greater crop yields, including pathogen response, water retention, and greater shelf life. However, the molecular mode of action as to how DMN brings about these changes within the potato is not well understood. Two years of RNA‐seq data demonstrate extensive changes in gene expression within potato samples treated with DMN at different times throughout the year. Significant changes have been highlighted among a particular group of genes located on chromosome one. This group of genes codes for a pathogenesis‐related‐protein, PR5. As an extracellular protein, PR5 has an extensive signal transduction that responds to pathogens and abiotic stress. Among the PR5 family is a group of cytosine‐rich proteins called osmotins. Osmotin is a ubiquitous protein among several plant species and serves as a useful molecular marker for the systemic acquired resistance response, which is analogous to the innate immune system in plants. Gene expression measurements were taken over a six month period, during which dormancy was naturally breached. RNA‐seq data reveals 2‐3 fold increases between measurements taken before and as dormancy was breaking. After dormancy was breached, PR5 gene expression continued to rise significantly in comparison to previous measurements. These trends in gene regulation imply that the PR5 expression proceeds concurrently with sprout growth in DMN treated potatoes, and are related to the systemic changes seen from the outside of the potato. Phylogenetic analysis reveals the PR5 genes with the greatest changes in expression (7865 and 7870) demonstrate the greatest homology among their transcripts. Current analysis is being done using qPCR primers directed towards genes 7865 and 7870. Expression levels from qPCR should mirror the RNA‐seq data, in addition to demonstrate more immediate expression following DMN treatment. It has been hypothesized that gene expression spikes in prominent PR5 genes (7865 and 7870) will signify a broad molecular mode of action DMN plays inside S.tuberosum.Support or Funding InformationSupported in part by a grant from the 1,4‐Group, Meridian, ID.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.