title: Bimodal dynamics of primary metabolism-related responses in tolerant potato-Potato virus Y interaction.
abstract: BACKGROUND
  Potato virus Y (PVY) is a major pathogen that causes substantial economic losses in worldwide potato production. Different potato cultivars differ in resistance to PVY, from severe susceptibility, through tolerance, to complete resistance. The aim of this study was to better define the mechanisms underlying tolerant responses of potato to infection by the particularly aggressive PVY(NTN) strain. We focused on the dynamics of the primary metabolism-related processes during PVY(NTN) infection.
  
  
  RESULTS
  A comprehensive analysis of the dynamic changes in primary metabolism was performed, which included whole transcriptome analysis, nontargeted proteomics, and photosynthetic activity measurements in potato cv. Désirée and its transgenic counterpart depleted for accumulation of salicylic acid (NahG-Désirée). Faster multiplication of virus occurred in the NahG-Désirée, with these plants developing strong disease symptoms. We show that while the dynamics of responses at the transcriptional level are extensive and bimodal, this is only partially translated to the protein level, and to the final functional outcome. Photosynthesis-related genes are transiently induced before viral multiplication is detected and it is down-regulated later on. This is reflected as a deficiency of the photosynthetic apparatus at the onset of viral multiplication only. Interestingly, specific and constant up-regulation of some RuBisCO transcripts was detected in Désirée plants, which might be important, as these proteins have been shown to interact with viral proteins. In SA-deficient and more sensitive NahG-Désirée plants, consistent down-regulation of photosynthesis-related genes was detected. A constant reduction in the photochemical efficiency from the onset of viral multiplication was identified; in nontransgenic plants this decrease was only transient. The transient reduction in net photosynthetic rate occurred in both genotypes with the same timing, and coincided with changes in stomatal conductivity.
  
  
  CONCLUSIONS
  Down-regulation of photosynthesis-related gene expression and decreased photosynthetic activity is in line with other studies that have reported the effects of biotic stress on photosynthesis. Here, we additionally detected induction of light-reaction components in the early stages of PVY(NTN) infection of tolerant interaction. As some of these components have already been shown to interact with viral proteins, their overproduction might contribute to the absence of symptoms in cv. Désirée.
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Vecna pot 111, Ljubljana, Slovenia. tjasa.stare@nib.si.
authors.forename: Tjaša
authors.initials: T
authors.lastname: Stare
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Vecna pot 111, Ljubljana, Slovenia. ziva.ramsak@nib.si.
authors.forename: Živa
authors.initials: Ž
authors.lastname: Ramšak
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Vecna pot 111, Ljubljana, Slovenia. andrej.blejec@nib.si.
authors.forename: Andrej
authors.initials: A
authors.lastname: Blejec
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Vecna pot 111, Ljubljana, Slovenia. katja.stare@nib.si.
authors.forename: Katja
authors.initials: K
authors.lastname: Stare
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Vecna pot 111, Ljubljana, Slovenia. neza.turnsek@nib.si.
authors.forename: Neža
authors.initials: N
authors.lastname: Turnšek
authors.affiliation: Department of Ecogenomics and Systems Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria. wolfram.weckwerth@univie.ac.at.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Weckwerth
authors.affiliation: Department of Ecogenomics and Systems Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria. stefanie.wienkoop@univie.ac.at.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Wienkoop
authors.affiliation: Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia. dominik.vodnik@bf.uni-lj.si.
authors.forename: Dominik
authors.initials: D
authors.lastname: Vodnik
authors.affiliation: Department of Biotechnology and Systems Biology, National Institute of Biology, Vecna pot 111, Ljubljana, Slovenia. kristina.gruden@nib.si.
authors.forename: Kristina
authors.initials: K
authors.lastname: Gruden
mesh_terms: D060467:Disease Resistance; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D010788:Photosynthesis; D018515:Plant Leaves / Q000235:genetics / Q000821:virology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism / Q000821:virology; D017800:Potyvirus / Q000235:genetics / Q000502:physiology*; D020156:Salicylic Acid / Q000378:metabolism; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism / Q000821:virology; D014779:Virus Replication
chemical_list: D010940:Plant Proteins; D020156:Salicylic Acid