Water limitation and rootstock genotype interact to alter grape berry metabolism through transcriptome reprogramming

Abstract

Grapevine is a perennial crop often cultivated by grafting a scion cultivar on a suitable rootstock. Rootstocks influence scions, particularly with regard to water uptake and vigor. Therefore, one of the possibilities to adapt viticulture to the extended drought stress periods is to select rootstocks conferring increased tolerance to drought. However, the molecular mechanisms associated with the ability of rootstock/scion combination to influence grape berry metabolism under drought stress are still poorly understood. The transcriptomic changes induced by drought stress in grape berries (cv. Pinot noir) from vines grafted on either 110R (drought-tolerant) or 125AA (drought-sensitive) rootstock were compared. The experiments were conducted in the vineyard for two years and two grape berry developmental stages (50% and 100% veraison). The genome-wide microarray approach showed that water stress strongly impacts gene expression in the berries, through ontology categories that cover cell wall metabolism, primary and secondary metabolism, signaling, stress, and hormones, and that some of these effects strongly depend on the rootstock genotype. Indeed, under drought stress, berries from vines grafted on 110R displayed a different transcriptional response compared to 125AA-concerning genes related to jasmonate (JA), phenylpropanoid metabolism, and pathogenesis-related proteins. The data also suggest a link between JA and secondary metabolism in water-stressed berries. Overall, genes related to secondary metabolism and JA are more induced and/or less repressed by drought stress in the berries grafted on the drought-sensitive rootstock 125AA. These rootstock-dependent gene expression changes are relevant for berry composition and sensory properties.

Grapevine adaptations to water stress: new perspectives about soil/plant interactions

“…In spite of the recognised value of rootstock selection for improving scion's adaptability to specific soil conditions, much of the information available on the drought tolerance of commercially available rootstocks and on differences generated by rootstock/scion combinations has been for long time mainly based on anecdotal evidence or visual comparisons (Soar et al 2006a). In the recent years, more attention has been devoted to the study of the influence of rootstock genotype to scion gas exchange as a consequence of its intrinsic characteristics (genetic, anatomical and physiological specificities of the root system) and of the metabolic control imposed via hormonal signalling (Soar et al 2006a, b;Koundouras et al 2008;Tandonnet et al 2010;Comas et al 2010;Alsina et al 2011;Marguerit et al 2012;Tramontini et al 2013b;Berdeja et al 2015;Ollat et al 2015).…”

Evaluating the involvement and interaction of abscisic acid and miRNA156 in the induction of anthocyanin biosynthesis in drought-stressed plants

“…According to these studies, drought stress conditions induce changes in the expression of several key genes involved in the anthocyanin biosynthetic pathway (Castellarin et al 2007b;André et al 2009;Giordano et al 2016). In particular, drought stress induces an upregulation of expression of CHS, Flavanone 3-hydroxylase (F3H), Flavonoid 3 0 ,5 0 -hydroxylase (F3 0 5 0 H), DFR, UDP-glucose:flavonoid 3-O-glucosyl transferase (UFGT), O-methyl-transferase (OMT), as well as transcription factors, such as Myeloblastosis A (MYBA), Myeloblastosis 5a (MYB5a), and MYB112 (Nagabhushana and Reddy 2004;Castellarin et al 2007a, b;André et al 2009;Borsani et al 2010;Martínez-Lüscher et al 2014;Berdeja et al 2015;Lotkowska et al 2015). The upregulation of the expression of these structural and regulatory genes involved in the phenylpropanoid pathway results in an increased number of enzymes available for catalysis of the biosynthesis reactions and thus results in an increased number of anthocyanins at the cellular level.…”

Survival strategies of citrus rootstocks subjected to drought

“…Rootstock selection and improvement with the goal of increasing plant water use efficiency is an efficient strategy to minimize the effects of climate changes on plant production5. Grafting is a millenary technique widely used in several different cultures6.…”