How Do Novel M-Rootstock (Vitis Spp.) Genotypes Cope with Drought?

Abstract

Most of the vineyards around the world are in areas characterized by seasonal drought, where water deficits and high temperatures represent severe constraints on the regular grapevine growth cycle. Although grapevines are well adapted to arid and semi-arid environments, water stress can cause physiological changes, from mild to irreversible. Screening of available Vitis spp. genetic diversity for new rootstock breeding programs has been proposed as a way for which new viticulture challenges may be faced. In 2014, novel genotypes (M-rootstocks) were released from the University of Milan. In this work, the behavior of M1, M3 and M4 in response to decreasing water availabilities (80%, 50% and 20% soil water content, SWC) was investigated at the physiological and gene expression levels, evaluating gas exchange, stem water potential and transcript abundances of key genes related to ABA (abscisic acid) biosynthesis (VvZEP, VvNCED1 and VvNCED2) and signaling (VvPP2C4, VvSnRK2.6 and VvABF2), and comparing them to those of cuttings of nine commercial rootstocks widely used in viticulture. M-rootstocks showed a change at physiological levels in severe water-stressed conditions (20% soil water content, SWC), reducing the stomatal conductance and stem water potential, but maintaining high photosynthetic activity. Water use efficiency was high in water-limiting conditions. The transcriptional changes were observed at 50% SWC, with an increment of transcripts of VvNCED1 and VvNCED2 genes. M-rootstocks showed similar behavior to 1103P and 110R rootstocks, two highly tolerant commercial genotypes. These rootstocks adopted a tolerant strategy to face water-stressed conditions.

Back to the Origins: Background and Perspectives of Grapevine Domestication

“…The Vitis genus counts around 60–70 taxa widespread throughout Eurasia and Northern America and several of them are inter-fertile [ 81 , 146 ]. Wild grapes are adapted to a wide range of climatic conditions and harbour genes resistant or tolerant towards both biotic and abiotic stresses, and several taxa are used today, as in the past, to produce rootstocks resistant to pathogens and pests, to drought and salinity, as well as cultivars characterised by a good quality of fruit and suitable for winemaking [ 147 , 148 , 149 , 150 , 151 ]. Thus, the genetic material conserved in wild grapes is a source of resistance to several stresses useful to improve the cultivars by traditional agronomic strategies or modern genomic editing methodologies [ 152 ].…”

Physiological and Transcriptional Responses to Saline Irrigation of Young ‘Tempranillo’ Vines Grafted Onto Different Rootstocks

“…It is important to bear this in mind when interpreting the results, especially the transcriptome analyses, because of the combination of two Vitis spp. Genotypes are studied by evaluating only one of them, i.e., Vitis vinifera L. In comparison, most of the grapevine transcriptomics responses reported in the literature have been assessed on a single genotype, i.e., directly in the own-rooted Vitis vinifera ( Cramer et al, 2007 ; Guan et al, 2018 ; Das and Majumder, 2019 ; Lehr et al, 2022 ) or on the rootstock without grafting ( Gong et al, 2011 ; Henderson et al, 2014 ; Meggio et al, 2014 ; Corso et al, 2015 ; Vannozzi et al, 2017 ; Fu et al, 2019 ; Çakır Aydemir et al, 2020 ), and if carried out in both the scion and the rootstock, they have been under highly controlled conditions ( Upadhyay et al, 2018 ; Bianchi et al, 2020 ; Franck et al, 2020 ; Baggett et al, 2021 ), i.e., not under real field-grown conditions.…”

“…Therefore, the objective of the present research was to evaluate the physiology and transcriptomics underlying the performance against salinity of two new rootstocks, M1 and M4, compared to the well-known salinity-tolerant 1103P ( Walker et al, 2010 ; Bianchi et al, 2020 ). In this work the experimental hypothesis was that the M-rootstocks may confer better salinity tolerance to the scion than the 1103P through enhanced uptake of salt-stress-contesting ions such as calcium, as well as vigor declining ability, in the case of the M1 ( Porro et al, 2013 ; Vannozzi et al, 2017 ), and because of the leaf build-up of inorganic osmolytes and sodium-antagonists, such as potassium, in the case of the M4 ( Meggio et al, 2014 ).…”

Adapting Grapevine Productivity and Fitness to Water Deficit by Means of Naturalized Rootstocks

“…In the naturalized R32 rootstock tissues grafted to cv Sy, the upregulation of genes of Phenylpropanoid metabolic process and pigment accumulation was determined in response to water deficit (Franck et al, 2020 ), enhancing plant survival in the presence of abiotic stress. M-rootstocks have also displayed adaptive traits, such as reducing the stomatal conductance and stem water potential while maintaining high photosynthetic activity with high Water Use Efficiency in water-limiting conditions (Bianchi et al, 2020 ). The capacity of M4 to satisfy the water demand of the scion under limited water availability has shown a delayed stomatal closure, allowing higher photosynthetic activity, which is also related to a reduced activation of ABA signaling both in the root and the leaf level (Prinsi et al, 2021 ).…”

“…Although scion-rootstock interactions in drought tolerance have been studied (Serra et al, 2014 ; Tomás et al, 2014 ; Bianchi et al, 2020 ), the diversity of rootstocks adapted to dryer conditions is limited. Recent studies in rootstock effects were evaluated, and differences in fruit yield, pruning weight, budburst, fruit set, bunch weight, berry weight, berry diameter, and rachis weight between nine rootstocks in semiarid conditions were determined along with their effects on nutrient uptake (Ibacache et al, 2016 , 2020 ).…”