Martinez-Lüscher, J.D. (Johann David)
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- Source–Sink manipulations have major implications for grapevine berry and wine flavonoids and aromas that go beyond the changes in berry sugar accumulation(Elsevier, 2023) Kaan-Kurtural, S. (Sahap); Martinez-Lüscher, J.D. (Johann David)Sugar levels in grape berries are necessary for wine production but also, they are the main driver of most ripening processes. Sugar levels are very responsive to canopy and crop load adjustments. The aim of this study is to test the effect of different levels of defoliation and cluster thinning on grape ripening and wine composition. ‘Cabernet sauvignon’ grapevines (Vitis vinifera L.) were subjected to defoliation (keeping 100 %, 66 % and 33 % of the leaves) and fruit thinning treatments (keeping 100 %, 66 % and 33 % of the clusters) combined in a factorial design. The experiment was repeated for 2 consecutive seasons (2017 and 2018) and the plants were left untreated for a third season (2019) to observe the carry-over effects of the treatments. The treatments implied precise adjustments of leaf and cluster numbers. However, the proportion of leaf area to fruit mass tended to compensate each other and interact resulting in smaller differences in leaf area or fruit mass by harvest. Berry mass was strongly reduced by defoliation even in the subsequent season where no defoliation was applied. Berry ripening indicators (soluble solids, acidity and anthocyanin levels) were also more affected by defoliation than fruit thinning. Anthocyanin profile was shifted to a higher proportion of Malvidin-derived anthocyanins for defoliated vines and lower proportion of Malvidin-derived anthocyanins in the case of thinned vines. However, when it came down to wine, the physicochemical parameters as well as the aroma profile were more affected by cluster thinning. There was a clear relationship between sugar levels of the unfermented must and many winearoma compounds. Green aromas (2-isobutyl-3-methoxypyrazine, hexanol and cis-3-Hexen-1-ol) were among those presenting a negative correlation to must sugar whereas other compounds like Isobutyric acid, Benzyl alcohol, 1-Octen-3-ol and γ-Nonalactone had a positive correlation. This study reveals a higher level of complexity of source sink relations where leaves and clusters do not only act as a source and a sink of carbon, respectively. Therefore, the results of this study should be considered before making comparisons of leaf area to fruit mass ratios across different vine-growing systems.
- Elevated CO2 alleviates the exacerbation of evapotranspiration rates of grapevine (Vitis vinifera) under elevated temperature(Elsevier B.V., 2024) Kozikova, D. (Daria); Pascual, I. (Inmaculada); Martinez-Lüscher, J.D. (Johann David); Goicoechea, N. (Nieves)Climate change is increasing crop water consumption while reducing precipitations in most places where grapevines are grown. This study aimed to quantify whole-plant water consumption of grapevines under climate change factors to determine what are the biggest contributors to changes in evapotranspiration under climate change conditions. Two experiments were carried out: i) Cabernet Sauvignon grafted onto 110 R grown in the temperature gradient greenhouses (TGG) exposed to elevated CO2 (700 μmol mol− 1) and/or elevated temperature (+4 ◦C) and ii) Tempranillo vegetative cuttings grown in the controlled environment greenhouses (CEG) exposed to ambient CO2 and standard temperatures (i.e CA24◦C) or elevated CO2 combined with elevated temperature (i.e CE28◦C) under cyclic water deficit conditions. In the overall, the combination of elevated CO2 and elevated temperature did not increase pot evapotranspiration, and in the only case this happened, it was mediated by a greater leaf area per plant. There was an interaction in which CO2 compensated for the increase in evapotranspiration induced by elevated temperature. Plants under elevated CO2 and elevated temperature (CETE) had lower stomatal conductance which resulted in similar transpiration rates to plants under ambient CO2 and ambient temperature conditions (CATA) despites the 4 ◦C increase. Net assimilation was greater under elevated CO2, and thus, instantaneous water use efficiency (WUE). Pot evapotranspiration was correlated to parameters such as leaf area per plant, gas exchange transpiration rates, reference evapotranspiration and plant available water content in the substrate. Pot lysimeters are a good compromise to study whole-plant water consumption rates under controlled conditions. Climate change conditions will likely continue to threat the sustainability of crops due to water shortages, however, our results point out that the interaction between elevated temperature and CO2 should be considered. The sensitivity of plant responses to elevated CO2 could be exploited as a key trait for the adaptation of crops to climate change.
- Grapevine varieties show different sensitivities to flavonoid alterations caused by high temperatures under two irrigation conditions(Elsevier Ltd., 2024) Pascual, I. (Inmaculada); Martinez-Lüscher, J.D. (Johann David); Goicoechea, N. (Nieves); Antolin-Bellver, M.C. (M. Carmen); Irigoyen, J.J. (Juan Jose)This study aimed to assess the response of four red grapevine (Vitis vinifera L.) varieties to elevated temperature, drought and their combination, focusing on the concentration and profile of grape flavonoids. Fruit-bearing cuttings of Tempranillo, Cabernet Sauvignon, Merlot and Grenache grew in greenhouses under, either ambient temperature (T) or ambient temperature + 4 ◦C (T+4). Plants also received either full irrigation (FI, substrate field capacity) or deficit irrigation (DI, 50 % substrate field capacity). In general, T+4 decreased the concentration of anthocyanins, but DI mitigated this effect. T+4 and DI increased the abundance of methylated anthocyanins and flavonols with additive effects. Grapes under T+4 had higher abundance of acylated anthocyanins, while DI increased the proportion of tri-hydroxylated anthocyanins and flavonols. The impact of interacting elevated temperature and drought on grape composition was genotype dependent. In terms of anthocyanin concentration and profile, Tempranillo was the most affected variety, whereas Grenache was less sensitive.
- Sensitivity of grapevine phenology to water availability, temperature and CO2 concentration(2016) Vucetic, V. (Visnja); Morales, F. (Fermin); Delrot, S. (Serge); Kizildeniz, T. (Tefide); Martinez-Lüscher, J.D. (Johann David); Pascual-Elizalde, I. (Inmaculada); Gomès, E. (Eric); Van-Leeuwen, H.C. (Hans C.); Luedeling, E. (Eike); Irigoyen, J.J. (Juan Jose); Dai, Z. (Zhanwu)In recent decades, mean global temperatures have increased in parallel with a sharp rise in atmospheric carbon dioxide (CO2) levels, with apparent implications for precipitation patterns. The aim of the present work is to assess the sensitivity of different phenological stages of grapevine to temperature and to study the influence of other factors related to climate change (water availability and CO2 concentration) on this relationship. Grapevine phenological records from 9 plantings between 42.75°N and 46.03°N consisting of dates for budburst, flowering and fruit maturity were used. In addition, we used phenological data collected from 2 years of experiments with grapevine fruit-bearing cuttings with two grapevine varieties under two levels of water availability, two temperature regimes and two levels of CO2. Dormancy breaking and flowering were strongly dependent on spring temperature, while neither variation in temperature during the chilling period nor precipitation significantly affected budburst date. The time needed to reach fruit maturity diminished with increasing temperature and decreasing precipitation. Experiments under semi-controlled conditions revealed great sensitivity of berry development to both temperature and CO2. Water availability had significant interactions with both temperature and CO2; however, in general, water deficit delayed maturity when combined with other factors. Sensitivities to temperature and CO2 varied widely, but higher sensitivities appeared in the coolest year, particularly for the late ripening variety, ‘White Tempranillo’. The knowledge gained in whole plant physiology and multi stress approaches is crucial to predict the effects of climate change and to design mitigation and adaptation strategies allowing viticulture to cope with climate change.
- Characterization of the adaptive response of grapevine (cv. Tempranillo) to UV-B radiation under water deficit conditions(2015) Morales, F. (Fermin); Aguirreolea, J. (Jone); Delrot, S. (Serge); Martinez-Lüscher, J.D. (Johann David); Pascual-Elizalde, I. (Inmaculada); Sanchez-Diaz, M. (Manuel); Gomès, E. (Eric)This work aims to characterize the physiological response of grapevine (Vitis vinifera L.) cv. Tempranillo to UV-B radiation under water deficit conditions. Grapevine fruit-bearing cuttings were exposed to three levels of supplemental biologically effective UV-B radiation (0, 5.98 and 9.66 kJ m−2 day−1) and two water regimes (well watered and water deficit), in a factorial design, from fruit-set to maturity under glasshouse-controlled conditions. UV-B induced a transient decrease in net photosynthesis (Anet), actual and maximum potential efficiency of photosystem II, particularly on well watered plants. Methanol extractable UV-B absorbing compounds (MEUVAC) concentration and superoxide dismutase activity increased with UV-B. Water deficit effected decrease in Anet and stomatal conductance, and did not change non-photochemical quenching and the de-epoxidation state of xanthophylls, dark respiration and photorespiration being alternative ways to dissipate the excess of energy. Little interactive effects between UV-B and drought were detected on photosynthesis performance, where the impact of UV-B was overshadowed by the effects of water deficit. Grape berry ripening was strongly delayed when UV-B and water deficit were applied in combination. In summary, deficit irrigation did not modify the adaptive response of grapevine to UV-B, through the accumulation of MEUVAC. However, combined treatments caused additive effects on berry ripening.
- Effects of UV-B radiation on grapevine (Vitis vinifera cv. Tempranillo) leaf physiology and berry composition, framed within the climate change scenario (water deficit, elevated CO2 and elevated temperature)(2015) Martinez-Lüscher, J.D. (Johann David); Aguirreolea, J. (Jone); Pascual-Elizalde, I. (Inmaculada)The aim of the thesis was to assess the effect of UV-B radiation on grapevine Vitis vinifera cv. Tempranillo leaf physiology and grape berry composition, framed within the climate change scenario. Grapevine fruit-bearing cuttings were exposed to three UV-B doses (0, 5.98, 9.66 kJ m-2 d-1) under greenhouse conditions. The combined effects of UV-B and water deficit, as well as, UV-B and elevated CO2-temperature (700 ppm, +4ºC), applied from fruit set to maturity were also tested. The results show that initial down-regulation of photosynthesis was followed by an acclimation, mediated by the accumulation of UV-B absorbing compounds and antioxidant response elicitation (flavonoids and antioxidant enzymes). Berry ripeness was delayed by UV-B exposure and water deficit, especially when they were applied in combination, whereas it was hastened by elevated CO2-temperature. In the last case, UV-B attenuated the effect of elevated CO2 and temperature. Changes in berry ripening rates were associated with changes in photosynthetic performance. Grape berry skin flavonol and anthocyanin concentration was increased by UV-B, mainly due to the up-regulation of the structural (CHS, F3¿H, FLS, UFGT and GST) and regulatory genes (MYBF1 and MYBA1) committed to their synthesis. Quantitative changes in flavonol concentration induced by UV-B were always associated with qualitative changes in flavonol profile (i.e. increased relative abundance of mono- and disubstituted flavonols), as a result of the competition of FLS with flavonoid hydroxylases (F3¿H and F3¿5¿H) for the same substrates. The up-regulation of FLS and F3¿5¿H by UV-B radiation and water deficit, respectively, resulted in an interactive effect on the flavonol B ring hydroxylation pattern. Under elevated CO2-temperature anthocyanin-sugar accumulation was decoupled. However, UV-B partially alleviated this uncoupling by up-regulating anthocyanin biosynthesis and modulating berry ripening rates.