Identification of grapevine marker genes for early, non‐destructive Eutypa lata infection diagnosis

Abstract

Eutypa lata is the causal agent of eutypa dieback, a highly damaging trunk disease affecting all grape‐growing areas, with currently neither an efficient curative treatment nor an early non‐destructive diagnostic method. The present work was carried out to discover grapevine genes expressed in response to the presence of E. lata that could be useful to develop an early (before visible foliar symptoms) and non‐destructive (using grapevine leaves) diagnostic tool. Microarray analyses were carried out from (i) infected plants showing characteristic E. lata foliar and vascular symptoms and positive pathogen recovery from vascular lesions (S+R+), (ii) infected plants showing no symptoms (S−R+), and (iii) symptomless plants with negative pathogen recovery (S−R−). Vineyard and greenhouse‐grown plants, naturally or artificially infected respectively, and uninoculated controls were characterized and leaf RNA was hybridized with 15k operon grapevine oligonucleotide microarrays. Among the grapevine genes differentially expressed between S−R+ and S−R− plants in greenhouse and vineyard conditions, 10 were highlighted as robust candidate genes for diagnosis: seven were specifically involved in response to infection and three were associated with symptom absence. Five were confirmed to be effective diagnostic marker genes usable in a qRT‐PCR‐based test performed on RNA extracted from grapevine leaves cultivated in either greenhouse or vineyard conditions. Furthermore, their expression profiles in response to infection with E. lata or other major grapevine fungi (Erysiphe necator, Plasmopara viticola, Botrytis cinerea) could be distinguished. The usefulness of these genes to develop an early and non‐destructive method for diagnosis of E. lata infection is discussed with regard to the advantages and drawbacks of previous E. lata diagnostic studies.

Variations in Early Response of Grapevine Wood Depending on Wound and Inoculation Combinations with Phaeoacremonium aleophilum and Phaeomoniella chlamydospora

“…Taken together, these approaches open a new field in the study of grapevine-microbe interactions in the context of GTDs and open the possibility of analyzing gene expression in trunk tissues. The microarray technique is available and was used to study eutypiosis in leaves ( Camps et al, 2010 , 2014 ). The RNAseq technique may highlight changes in gene expression for genes specific to trunk response; a function in trunk tissue that remains to be characterized.…”

Comparison of the Molecular Responses of Tolerant, Susceptible and Highly Susceptible Grapevine Cultivars During Interaction With the Pathogenic Fungus Eutypa lata

“…Real-time quantitative PCR was carried out using the GoTaq qPCR MasterMix (Promega) and a Mastercycler realplex2 instrument (Eppendorf). In this work, four V. vinifera reference genes were tested, elongation factor EF1γ and EF1 α , glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and actin, described in several previous reports (Reid et al, 2006; Nicolas et al, 2013; Camps et al, 2014). The stability of all these genes was tested in our biological conditions.…”

The Hidden Diversity of Diatrypaceous Fungi in China

“…Notes: Species of Eutypa are the causal agents of dieback of grapevine, apricots, and cherries Gubler, 2004, 2010;Baumgartner et al, 2010;Camps et al, 2010;Blanco-Ulate et al, 2013;Camps et al, 2014). The genus is characterized by stromata which are irregular in shape, as confluent bumps, with conspicuous, scattered, roundish to prominent ostioles on the host surface.…”