Characterization of the Biogenic Volatile Organic Compounds (BVOCs) and Analysis of the PR1 Molecular Marker in Vitis vinifera L. Inoculated with the Nematode Xiphinema index.

Giulia Castorina,Marcello Iriti,Gabriella Consonni,Flaminia Grassi,Sara Vitalini,Roberto Oberti,Enrico Ferrari,Monica Bononi,Aldo Calcante

doi:10.3390/ijms21124485

Giulia Castorina, Marcello Iriti + Show 7 more

Open Access

https://doi.org/10.3390/ijms21124485

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Abstract

Upon pathogen attack, plants very quickly undergo rather complex physico-chemical changes, such as the production of new chemicals or alterations in membrane and cell wall properties, to reduce disease damages. An underestimated threat is represented by root parasitic nematodes. In Vitis vinifera L., the nematode Xiphinema index is the unique vector of Grapevine fanleaf virus, responsible for fanleaf degeneration, one of the most widespread and economically damaging diseases worldwide. The aim of this study was to investigate changes in the emission of biogenic volatile organic compounds (BVOCs) in grapevines attacked by X. index. BVOCs play a role in plant defensive mechanisms and are synthetized in response to biotic damages. In our study, the BVOC profile was altered by the nematode feeding process. We found a decrease in β-ocimene and limonene monoterpene emissions, as well as an increase in α-farnesene and α-bergamotene sesquiterpene emissions in nematode-treated plants. Moreover, we evaluated the PR1 gene expression. The transcript level of PR1 gene was higher in the nematode-wounded roots, while in the leaf tissues it showed a lower expression compared to control grapevines.

Highlights

The European Union is the world’s main wine producer, with a share of about 60% [1]
hypersensitive response (HR) settlement involves the induction of many defense mechanisms such as the strengthening of cell walls, salicylic acid (SA) pathway, synthesis of phytoalexins organic molecules and HR-related molecules (H2O2) which are among the main molecules secreted and produced during the plant/pathogen interaction [20]
Hamamouch and colleagues [55] demonstrated that in A. thaliana plants, parasitized by Meloidogyne incognita, PR1 proteins were highly expressed in roots, while their expression was down-regulated in leaves

Summary

Introduction

The European Union is the world’s main wine producer, with a share of about 60% [1]. Given the economic relevance of Vitis vinifera L., grapevine pests are of rising interest to agrochemical companies and plant researchers. Plants defend themselves from parasite attacks in different ways, in continuous coevolution with pathogens [16] Their stationary status makes them vulnerable but plants limit damage using a variety of defense mechanisms [17], so disease is an exceptional condition rather than normality. HR settlement involves the induction of many defense mechanisms such as the strengthening of cell walls, salicylic acid (SA) pathway, synthesis of phytoalexins organic molecules and HR-related molecules (H2O2) which are among the main molecules secreted and produced during the plant/pathogen interaction [20]. Plants produce root-specific volatile organic compounds (VOCs) [27], which can influence the rhizosphere and plant-pathogen interaction [28,29,30,31]. IInn tthhiiss ccoonntteexxtt,, wwee iinnvveessttiiggaatteedd tthhee rreessppoonnssee ooff ggrraappeevviinnee ccuuttttiinnggss ttoo tthhee nneemmaattooddee ffeeeeddiinngg pprroocceessss tthhrroouugghh BBVVOOCC pprrooffiilliinngg aanndd PPRR11 ggeennee eexxpprreessssiioonn,, wwiitthh tthhee aaiimm ooff eexxpplloorriinngg tthhee ppootteennttiiaall ooff tthhiiss aapppprrooaacchh iinn tthhee ddeetteeccttiioonn ooff aann eeaarrllyy ssiiggnnaall ooff tthhee nneemmaattooddee aattttaacckk oonn tthhee ppllaanntt rroooott ssyysstteemm

TThheeBBVVOOCCPPrrooffiillee

Plant Material

Nematode Isolation

SPME Sampling and GC-MS Analysis

Findings

Quantitative Gene Expression Analysis