Characterization of volatile organic compounds in grafted tomato plants upon potyvirus necrotic infection

A headspace solid-phase microextraction-gas chromatography-mass spectrometry(HS-SPME/GC-MS)method was used to study the volatile organic compounds(VOCs)associated with the differential immune response of tomato plants infected with the recombinant strain of potato virus Y(PVY^(C)-to),necrogenic to tomato.Analysis was carried out in UC82(UC),a virus susceptible tomato variety,comparing the same UC plants grafted or not onto a virus tolerant tomato ecotype,Manduria(Ma);the three types of samples used for the GC-MS analysis were mock-inoculated UC/Ma plants,UC/Ma+PVY^(C)-to and UC+PVY^(C)-to plants;the VOCs obtained were 111.Results from symptomatic PVY^(C)-to-infected UC plants showed a VOCs composition enriched in alcohols,fatty acid derivates,benzenoids,and salicylic acid derivatives,while in mock-inoculated UC/Ma plants VOCs were mainly characterized by methyl ester compounds.The VOC profile was in line with RNAseq data analyses,denoting that PVY^(C)-to viral RNA accumulation and disease symptoms induce the specific transcriptional activation of genes involved in VOCs biosynthesis.Furthermore,principal component analysis highlighted that VOCs of PVY^(C)-to-infected and mock-inoculated grafted plants were much closer each other than that of symptomatic PVY^(C)-to-infected non-grafted UC plants.These results suggest that VOCs profiles of tomato plants are related to the viral RNA accumulation,disease intensity and graft-derived tolerance to PVY^(C)-to infection.

Characterization of the Geographical and Varietal Origin of Wheat and Bread by Means of Nuclear Magnetic Resonance (NMR), Isotope Ratio Mass Spectrometry (IRMS) Methods and Chemometrics: A Review

In recent years, food authentication, in terms of geographical and varietal/animal origins, is considered of primary importance at all levels of the production process. Therefore, it is clear that there is an economic basis to develop analytical methods able to certify the declared origin of food products, in order to protect consumers and honest producers from fraud and unfair competition, respectively;consequently, during recent years, several food authentication techniques have been proposed. This review attempted to present in a critical way the contribution of High Resolution Nuclear Magnetic Resonance (HR-NMR) and Isotope Ratio Mass Spectrometry (IRMS) techniques in the assessment of quality and authenticity, mainly in terms of characterization of geographical and varietal origin, of wheat and wheat products, focusing on the most important studies to this direction.