naa a22 4500 528782495 20180924065513.0 cr unu---uuuuu 180924e20131104xx s 000 0 eng 10.3929/ethz-b-000075542 doi 10.1371/journal.pone.0078457 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/75542 Gusberti Michele RNA-Seq Analysis Reveals Candidate Genes for Ontogenic Resistance in Malus-Venturia Pathosystem [Elektronische Daten] [Michele Gusberti, Cesare Gessler, Giovanni A.L. Broggini] PLoS ONE Open access ethresearch Ontogenic scab resistance in apple leaves and fruits is a horizontal resistance against the plant pathogen Venturia inaequalis and is expressed as a decrease in disease symptoms and incidence with the ageing of the leaves. Several studies at the biochemical level tried to unveil the nature of this resistance; however, no conclusive results were reported. We decided therefore to investigate the genetic origin of this phenomenon by performing a full quantitative transcriptome sequencing and comparison of young (susceptible) and old (ontogenic resistant) leaves, infected or not with the pathogen. Two time points at 72 and 96 hours post-inoculation were chosen for RNA sampling and sequencing. Comparison between the different conditions (young and old leaves, inoculated or not) should allow the identification of differentially expressed genes which may represent different induced plant defence reactions leading to ontogenic resistance or may be the cause of a constitutive (uninoculated with the pathogen) shift toward resistance in old leaves. Differentially expressed genes were then characterised for their function by homology to A. thaliana and other plant genes, particularly looking for genes involved in pathways already suspected of appertaining to ontogenic resistance in apple or other hosts, or to plant defence mechanisms in general. In this work, five candidate genes putatively involved in the ontogenic resistance of apple were identified: a gene encoding an "enhanced disease susceptibility 1 protein” was found to be down-regulated in both uninoculated and inoculated old leaves at 96 hpi, while the other four genes encoding proteins (metallothionein3-like protein, lipoxygenase, lipid transfer protein, and a peroxidase 3) were found to be constitutively up-regulated in inoculated and uninoculated old leaves. The modulation of the five candidate genes has been validated using the real-time quantitative PCR. Thus, ontogenic resistance may be the result of the corresponding up- and down-regulation of these genes. Creative Commons Attribution 3.0 Unported http://creativecommons.org/licenses/by/3.0 ethresearch Gessler Cesare joint author Broggini Giovanni A.L. joint author PLoS ONE San Francisco, CA : Public Library of Science 8 (11), p. e78457 1932-6203 http://hdl.handle.net/20.500.11850/75542 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/75542 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 100 1- Gusberti Michele ETHRESEARCH 700 1- Gessler Cesare joint author ETHRESEARCH 700 1- Broggini Giovanni A.L. joint author ETHRESEARCH 773 0- PLoS ONE San Francisco, CA : Public Library of Science 8 (11), p. e78457 1932-6203 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access