title: Correspondence between symptom development of Colletotrichum graminicola and fungal biomass, quantified by a newly developed qPCR assay, depends on the maize variety.
abstract: BACKGROUND
  Penetration attempts of the hemibiotroph Colletotrichum graminicola may activate PAMP-triggered immunity (PTI) on different cultivars of Zea mays to different extent. However, in most events, this does not prevent the establishment of a compatible pathogenic interaction. In this study, we investigate the extent to which the host variety influences PTI. Furthermore, we assess whether visual disease symptoms occurring on different maize varieties reliably reflect fungal biomass development in planta as determined by qPCR and GFP tracing.
  
  
  RESULTS
  Employing a set of four maize varieties, which were selected from a panel of 27 varieties, for in-depth assessment of pathogenesis of the wild type strain of C. graminicola, revealed considerable differences in susceptibility as evidenced by symptom severity that decreased from variety Golden Jubilee to Mikado to Farmtop to B73. However, a newly developed qPCR assay and microscopical observation of a GFP-labelled strain showed that disease symptoms are in some instances inconsistent when compared with other indicators of susceptibility. Of the four varieties assessed, either Golden Jubilee, Mikado and B73, or Golden Jubilee, Farmtop and B73 showed a direct correlation between symptom and fungal biomass development. In a pairwise comparison, however, Mikado and Farmtop showed an inverse correlation for these features.
  
  
  CONCLUSIONS
  The genotype of maize contributes to the severity of symptoms resulting from an infection with C. graminicola. Partially, this may be attributed to the extent of PTI activated in different varieties, as reflected by papilla formation. Furthermore, when evaluating the susceptibility of a variety, it should be considered that symptom severity must not have to reflect the extent of fungal growth in the infected tissue.
authors.affiliation: Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Weihmann
authors.affiliation: Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Eisermann
authors.affiliation: Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.
authors.forename: Rayko
authors.initials: R
authors.lastname: Becher
authors.affiliation: Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.
authors.forename: Jorrit-Jan
authors.initials: JJ
authors.lastname: Krijger
authors.affiliation: Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.|Interdisziplinäres Zentrum für Nutzpflanzenforschung (IZN), Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Hübner
authors.affiliation: Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.|Interdisziplinäres Zentrum für Nutzpflanzenforschung (IZN), Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany.
authors.forename: Holger B
authors.initials: HB
authors.lastname: Deising
authors.affiliation: Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany. stefan.wirsel@landw.uni-halle.de.|Interdisziplinäres Zentrum für Nutzpflanzenforschung (IZN), Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120, Halle (Saale), Germany. stefan.wirsel@landw.uni-halle.de.
authors.forename: Stefan G R
authors.initials: SG
authors.lastname: Wirsel
mesh_terms: D018533:Biomass; D020231:Colletotrichum / Q000254:growth & development / Q000472:pathogenicity*; D004198:Disease Susceptibility; D015966:Gene Expression Regulation, Fungal; D018745:Genome, Plant; D005838:Genotype; D049452:Green Fluorescent Proteins / Q000378:metabolism; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D003313:Zea mays / Q000145:classification / Q000235:genetics* / Q000382:microbiology
chemical_list: D049452:Green Fluorescent Proteins
keywords: Colletotrichum graminicola; ETI; Maize; PTI; Papilla; Virulence; Zea mays