Sulphur dioxide evokes a large scale reprogramming of the grape berry transcriptome associated with oxidative signalling and biotic defence responses

Abstract

The grape and wine industries are heavily reliant on sulphite preservatives. However, the view that sulphites act directly on bacterial and fungal pathogens may be simplistic. Mechanisms of sulphur-enhanced defences are largely unknown; many sulphur-rich compounds enhance plant defences and sulphite can also have oxidative consequences via production of H2O2 or sulphitolysis. To investigate the effects of sulphur dioxide (SO2) on fresh table grapes (Vitis vinifera L. 'Crimson Seedless'), transcriptome analysis was carried out on berries treated with SO2 under commercial conditions for 21 d. We found a broad perturbation of metabolic processes, consistent with a large-scale stress response. Transcripts encoding putative sulphurmetabolizing enzymes indicated that sulphite was directed towards chelation and conjugation, and away from oxidation to sulphate. The results indicated that redox poise was altered dramatically by SO2 treatment, evidenced by alterations in plastid and mitochondrial alternative electron transfer pathways, up-regulation of fermentation transcripts and numerous glutathione S-transferases, along with a down-regulation of components involved in redox homeostasis. Features of biotic stress were up-regulated, notably signalling via auxin, ethylene and jasmonates. Taken together, this inventory of transcriptional responses is consistent with a long-term cellular response to oxidative stress, similar to the effects of reactive oxygen species.

Genome-Wide Identification and Analysis of the TIFY Gene Family in Grape

“…While VvPPD2 was slightly up-regulated upon treatment with JA, its expression was not significantly altered upon MeJA treatment. However, in a separate study in which harvested grape berries were treated with SA, MeJA, SO 2 or a combination of SA and MeJA [39], only three of the grape genes analyzed ( VvJAZ4 , VvJAZ5 and VvJAZ9 ) were significantly up-regulated upon MeJA treatment, while VvPPD1 was down-regulated upon SO 2 treatment.…”

Comparison of Transcriptional Changes to Chloroplast and Mitochondrial Perturbations Reveals Common and Specific Responses in Arabidopsis

“…However, it is apparent from a number of studies that these retrograde signals do not just affect the expression of genes encoding proteins targeted to the specific organelle, but also other cellular compartments and functional groups (Van Aken et al, 2007; Estavillo et al, 2011; Giraud et al, 2012). Recent studies have indicated for instance that mitochondrial perturbations can significantly affect functional categories such as plant-pathogen interactions, protein synthesis, and photosynthetic light reactions (Schwarzlander et al, 2012).…”

Impact of SO2 on Arabidopsis thaliana transcriptome in wildtype and sulfite oxidase knockout plants analyzed by RNA deep sequencing

“…Giraud et al (2012) reported a strong influence of 1-3 ll l À1 SO 2 on grape berries using microarray analyses. Although 600 nl l À1 SO 2 is a nontoxic dosage for Arabidopsis (Hänsch & Mendel, 2005), the first responses at the mRNA level were detected in WT [+], though to a lesser extent than detected in SO-KO [+].…”