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The present study aimed: i) to evaluate the impact of the changes in temperature and relative humidity (RH), projected by the year 2100, on grape ripening, and ii) to assess if bunch transpiration is a key physiological process involved in the advancement in grape development under future climate conditions. Fruit-bearing cuttings of Vitis vinifera L. cv. 'Tempranillo' were grown, from fruit set to maturity, in glasshouses under two conditions: 24°C/14°C and 55%/70% RH (day/night) (T) vs 28°C/18°C and 43%/58% RH (T+4). To elucidate the role of bunch transpiration in grape development in a future climate scenario, the bunches of half of the plants in the T+4 glasshouse were sprayed with an antitranspirant (AT+4). T+4 increased bunch transpiration, hastened the ripening process, increasing the rate of total soluble solid (TSS) accumulation and malic acid degradation, and reduced the concentration of total anthocyanins. The application of antitranspirant partially alleviated the effects of combined high temperature and low RH on maturation times, through lower TSS accumulation rates. Berries in AT+4 had the lowest concentrations of anthocyanins and color, likely related to a reduction in light transmittance by the antitranspirant film and to higher anthocyanin degradation due to the longer exposure to elevated temperatures. The results show a negative impact of elevated temperature and low RH on grape composition. The increased bunch transpiration under these conditions played an important role in the changes observed in phenology and sugar accumulation.

Grape berry respiration is a key process during maturation, since it influences must acidity. In recent literature, there are some reports showing measurements of bunch respiration, as CO2 efflux, from the point of view of the plant C balance. Traditionally, in the late 60 s and 70 s, grape berry respiration, either as CO2 or O2, was measured by slicing grape berries and using the standard Warburg method. Commercially available instruments adequate to measure gas exchange, particularly H2O (transpiration) and CO2 (respiration or photosynthesis), in small fruits (typically apples) are not suitable for a whole bunch or isolated grape berries. In this report, we present a low-cost, closed chamber system where the gases (CO2 and O2) are allowed to accumulate/be consumed, based on the use of sensors from Vaisala (CO2) and SST Sensing (O2), which can monitor respiration in a whole bunch of grape berries, or alternatively in isolated grape berries. Respiration was measured in whole Tempranillo bunches sampled at different phenological stages with the whole bunch respiration prototype. Results showed a decreasing trend of respiration from pea size to maturity (both measured as CO2 efflux and O2 uptake) with an almost constant CO2/O2 respiratory quotient of around 1.3. Data from the old literature postulated an increase in this respiratory quotient when grapes start to ripen. Since the measurement in a whole bunch modifies the relationship between the air volume circulating around the bunch as it grows in size with the phenological stage, we optimized the system by reducing as much as possible the air death volume using an alternative chamber for isolated grape berries. Measurements of Tempranillo grape berries collected at different phenological stages using this new closed system confirmed the decreased respiration trend throughout grape development and ripening period. Even most important, these respiration measurements resulted in a change of the CO2/O2 respiratory quoti

[Objective]: Maresin 1 (MaR1) is a docosahexaenoic acid-derived proresolving lipid mediator with insulin-sensitizing and anti-steatosis properties. Here, we aim to unravel MaR1 actions on brown adipose tissue (BAT) activation and white adipose tissue (WAT) browning. [Methods]: MaR1 actions were tested in cultured murine brown adipocytes and in human mesenchymal stem cells (hMSC)-derived adipocytes. In vivo effects of MaR1 were tested in diet-induced obese (DIO) mice and lean WT and Il6 knockout (Il6−/−) mice. [Results]: In cultured differentiated murine brown adipocytes, MaR1 reduces the expression of inflammatory genes, while stimulates glucose uptake, fatty acid utilization and oxygen consumption rate, along with the upregulation of mitochondrial mass and genes involved in mitochondrial biogenesis and function and the thermogenic program. In Leucine Rich Repeat Containing G Protein-Coupled Receptor 6 (LGR6)-depleted brown adipocytes using siRNA, the stimulatory effect of MaR1 on thermogenic genes was abrogated. In DIO mice, MaR1 promotes BAT remodeling, characterized by higher expression of genes encoding for master regulators of mitochondrial biogenesis and function and iBAT thermogenic activation, together with increased M2 macrophage markers. In addition, MaR1-treated DIO mice exhibit a better response to cold-induced BAT activation. Moreover, MaR1 induces a beige adipocyte signature in inguinal WAT of DIO mice and in hMSC-derived adipocytes. MaR1 potentiates Il6 expression in brown adipocytes and BAT of cold exposed lean WT mice. Interestingly, the thermogenic properties of MaR1 were abrogated in Il6−/− mice. [Conclusions]: These data reveal MaR1 as a novel agent that promotes BAT activation and WAT browning by regulating thermogenic program in adipocytes and M2 polarization of macrophages. Moreover, our data suggest that LGR6 receptor is mediating MaR1 actions on brown adipocytes, and that IL-6 is required for the thermogenic effects of MaR1.

Atmospheric CO2 levels and global temperatures are expected to rise in the next decades, and viticulture must face these changes. Within this context, exploiting the intra-varietal diversity of grapevine (Vitis vinifera L.) can be a useful tool for the adaptation of this crop to climate change. The aim of the present work was to study the effect of elevated temperature and elevated levels of atmospheric CO2, both individually and combined, on the growth, phenology and carbon partitioning of five clones of the cultivar Tempranillo (RJ43, CL306, T3, VN31 and 1084). The hypothesis that clones within the same variety that differ in their phenological development may respond in a different manner to the above mentioned environmental factors from a physiological point of view was tested. Grapevine fruit-bearing cuttings were grown from fruit set to maturity under two temperature regimes: ambient (T) vs elevated (ambient + 4°C, T + 4), combined with two CO2 levels: ambient (ca. 400 ppm, ACO2) vs elevated (700 ppm, ECO2), in temperature-gradient greenhouses (TGGs). Considering all the clones, elevated temperature hastened grape development and increased vegetative growth, but reduced grape production, the later most likely associated with the heat waves recorded during the experiment. Plants in the elevated CO2 treatments showed a higher photosynthetic activity at veraison and an increased vegetative growth, but they showed signs of photosynthetic acclimation to ECO2 at maturity according to the C:N ratio, especially when combined with high temperature. The combination of ECO2 and T + 4, mimicking climate change environmental conditions, showed additive effects in some of the parameters analyzed. The clones showed differences in their phenological development, which conditioned some responses to elevated CO2 and temperature in terms of vegetative production and C partitioning into different organs. The work adds new knowledge on the use of different grapevine clones, that c

The intra-varietal genetic diversity of grapevine (Vitis vinifera L.) may be exploited to maintain grape quality under future warm conditions, which may alter grape berry development and composition. The present study assesses the effects of elevated temperature on the development of berry, grape composition and anthocyanins:sugars ratio of thirteen clones of V. vinifera. cv. Tempranillo that differed in length of the ripening period (time from veraison to berry total soluble solids, mainly sugars, of ca. 22 °Brix). Two temperature regimes (24 °C/14 °C or 28 °C/18 °C, day/night) were imposed to grapevine fruit-bearing cuttings from fruit set to maturity under greenhouse-controlled conditions. Elevated temperature hastened berry development, with a greater influence before the onset of ripening, and reduced anthocyanin concentration, colour intensity and titratable acidity. The clones significantly differed in the number of days that elapsed between fruit set and maturity. At the same concentration of total soluble solids, the anthocyanin concentration was lower at 28 °C/18 °C than 24 °C/14 °C, indicating a decoupling effect of elevated temperature during berry ripening. Thermal decoupling was explained by changes in the relative rate of response of anthocyanin and sugar build-up, rather than delayed onset of anthocyanin accumulation. Clones differed in the degree of thermal decoupling, but it was directly associated with differences neither in the length of their ripening period nor in plant vigour.

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.

Continued emissions of CO2, derived from human activities, increase atmospheric CO2 concentration. The CO2 rise stimulates plant growth and affects yield quality. Effects of elevated CO2 on legume quality depend on interactions with N2-fixing bacteria and mycorrhizal fungi. Growth at elevated CO2 increases photosynthesis under short-term exposures in C3 species. Under long-term exposures, however, plants generally acclimate to elevated CO2 decreasing their photosynthetic capacity. An updated survey of the literature indicates that a key factor, perhaps the most important, that characteristically influences this phenomenon, its occurrence and extent, is the plant source–sink balance. In legumes, the ability of exchanging C for N at nodule level with the N2-fixing symbionts creates an extra C sink that avoids the occurrence of photosynthetic acclimation. Arbuscular mycorrhizal fungi colonizing roots may also result in increased C sink, preventing photosynthetic acclimation. Defoliation (Anthyllis vulneraria, simulated grazing) or shoot cutting (alfalfa, usual management as forage) largely increases root/shoot ratio. During re-growth at elevated CO2, new shoots growth and nodule respiration function as strong C sinks that counteracts photosynthetic acclimation. In the presence of some limiting factor, the legumes response to elevated CO2 is weakened showing photosynthetic acclimation. This survey has identified limiting factors that include an insufficient N supply from bacterial strains, nutrient-poor soils, low P supply, excess temperature affecting photosynthesis and/or nodule activity, a genetically determined low nodulation capacity, an inability of species or varieties to increase growth (and therefore C sink) at elevated CO2 and a plant phenological state or season when plant growth is stopped.

© 2014 Elsevier GmbH. Medicago sativa L. (alfalfa) can exhibit photosynthetic down-regulation when grown in greenhouse conditions under elevated atmospheric CO2. This forage legume can establish a double symbiosis with nitrogen fixing bacteria and arbuscular mycorrhizal fungi (AMF), which may increase the carbon sink effect of roots. Our aim was to assess whether the association of alfalfa with AMF can avoid, diminish or delay the photosynthetic acclimation observed in previous studies performed with nodulated plants. The results, however, showed that mycorrhizal (M) alfalfa at the end of their vegetative period had lower carbon (C) discrimination than non-mycorrhizal (NM) controls, indicating photosynthetic acclimation under ECO2 in plants associated with AMF. Decreased C discrimination was due to the acclimation of conductance, since the amount of Rubisco and the expression of genes codifying both large and small subunits of Rubisco were similar or slightly higher in M than in NM plants. Moreover, M alfalfa accumulated a greater amount of soluble sugars in leaves than NM plants, thus favoring a down-regulation effect on photosynthetic rates. The enhanced contents of sugars in leaves coincided with a reduced percentage of arbuscules in roots, suggesting decreased sink of carbohydrates from shoots to roots in M plants. The shorter life cycle of alfalfa associated with AMF in comparison with the NM controls may also be related to the accelerated photosynthetic acclimation in M plants. Further research is needed to clarify to what extent this behavior could be extrapolated to alfalfa cultivated in the field and subjected to periodic cutting of shoots under climatic change scenarios.

The association of Lactuca sativa L. with arbuscular mycorrhizal fungi (AMF) can benefit growth and induce the accumulation of mineral nutrients and antioxidants in leaves. Our objectives were (1) to assess to what extent growing season influence growth and nutritional quality of the green-leaf Batavia Rubia Munguía (BRM) and the red-leaf Maravilla de Verano (MV) lettuce cultivars; (2) to test if the growing season affected the effectiveness of AMF as enhancers of the nutritional quality of the aforementioned cultivars; and (3) to check if inoculation with AMF allows extending the season to cultivate these two lettuce cultivars, without a loss of plant growth or nutritional quality. Results showed that winter was the most favourable growing season for both types of lettuce but mycorrhizal plants cultivated in other seasons different from winter achieved higher or similar shoot biomass than their respective non-inoculated controls in winter. AMF induced the accumulation of Fe, proteins, carotenoids and anthocyanins in both cultivars of lettuce in winter and spring. In summer and autumn, both types of lettuce showed increased levels of anthocyanins when associated with AMF. Mycorrhizal BRM also had enhanced levels of K, sugars and ascorbate in winter and spring as well as increased amounts of Mg and Cu in winter and summer. Mycorrhizal MV had increased quantities of Cu, Zn and sugars in spring and Mn in autumn. After estimating intakes of mineral elements through the consumption of 150. g per day of fresh leaves from mycorrhizal lettuces we may affirm that there would not be toxicological risk according to the Recommended Daily Allowances (RDAs). The application of AMF could allow extending cultivation of lettuce to other periods not appropriate for producing non-mycorrhizal plants. © 2013 Elsevier B.V.

Lettuce (Lactuca sativa L.) is a major food crop within the European Union. The objective of this study was to test the potential nutritional quality of three types of lettuce consumed as salads: Lactuca sativa L. var. longifolia (commonly named Cogollos de Tudela) and two cultivars of Lactuca sativa L. var. capitata (Batavia Rubia Munguía and Maravilla de Verano). Distribution of sugars, proteins, minerals and antioxidant compounds (carotenoids, chlorophylls, phenolics, anthocyanins and ascorbate) between outer and inner leaves was tested. The potential benefits of each variety or cultivar were due to different compounds accumulated in leaves. Cogollos de Tudela showed higher levels of Mg and Ca in both external and internal leaves, and greater concentrations of Mn, chlorophylls and carotenoids in inner leaves than lettuces belonging to the var. capitata. Batavia Rubia Munguía had low quantity of Na and an important amount of K, Mg, Ca, Fe and Zn in outer leaves and it was the cultivar that accumulated the highest quantity of water in both outer and inner leaves. Maravilla de Verano showed the greatest contents of anthocyanins and ascorbate in external leaves. In the three cultivars some of the potentially beneficial compounds appeared in higher levels in the outer than in the inner leaves. Therefore, the complete elimination of the external leaves should be reconsidered when lettuces are consumed as salads or used as food crop for the ‘Fourth Range’ of vegetables.

The aim of the present study was to analyse the effect of elevated CO 2 at different temperature, inoculation with three Sinorhizobium meliloti strains and growth in two seasons (summer and autumn) on plant growth, photosynthesis and N 2 fixation (estimated as apparent nitrogenase activity, ANA). One of the objectives was to demonstrate that most efficient N 2-fixing strains could improve alfalfa forage production. The second objective was to test if S. meliloti strains alter their efficiency under climate change conditions. The third objective was to show if seasonal changes may modify alfalfa productivity. Interaction of CO 2 and temperature enhanced alfalfa dry matter in both seasons; however, plants produced more dry matter in autumn than in summer, due to the negative effect of elevated summer temperature on N 2-fixation. Higher yield in summer corresponded to plants in symbiosis with 102F78 strain being not related to enhanced nodule dry matter or apparent nitrogenase activity but to putative lower carbon consumption for N 2 fixing process. Contrariwise, in autumn the highest yield was obtained by 102F34 as a consequence of increased nodule dry matter induced under elevated CO 2 and temperature. © 2011 Elsevier B.V.

Elevated CO 2 may decrease alfalfa forage quality and in vitro digestibility through a drop in crude protein and an enhancement of fibre content. The aim of the present study was to analyse the effect of elevated CO 2, elevated temperature and Sinorhizobium meliloti strains (102F78, 102F34 and 1032 GMI) on alfalfa yield, forage quality and in vitro dry matter digestibility. This objective is in line with the selection of S. meliloti strains in order to maintain high forage yield and quality under future climate conditions. Plants inoculated with the 102F34 strain showed more DM production than those inoculated with 1032GMI; however, these strains did not show significant differences with 102F78 plants. Neutral or acid detergent fibres were not enhanced in plants inoculated with the 102F34 strain under elevated CO 2 or temperature and hence, in vitro dry matter digestibility was unaffected. Crude protein content, an indicator of forage quality, was negatively related to shoot yield. Plants inoculated with 102F78 showed a similar shoot yield to those inoculated with 102F34, but had higher crude protein content at elevated CO 2 and temperature. Under these climate change conditions, 102F78 inoculated plants produced higher quality forage. However, the higher digestibility of plants inoculated with the 102F34 strain under any CO 2 or temperature conditions makes them more suitable for growing under climate change conditions. In general, elevated CO 2 in combination with high temperature (Climate Change scenario) reduced IVDMD and CP content and enhanced fibre content, which means that animal production will be negatively affected. © 2012 Elsevier GmbH.

Sewage sludge has been used as N fertilizer because it contains some of inorganic N, principally as nitrate and ammonium ions. However, sewage sludge addition to legumes could result in impaired nodule metabolism due to the presence of inorganic N from sludge. A greenhouse experiment was conducted to examine the effects of sewage sludge on growth, photosynthesis, nitrogen assimilation and nodule metabolism in alfalfa (Medicago sativa L. cv. Aragón). Plants were grown in pots with a mixture of perlite and vermiculite (2:1, v/v). The experiment included three treatments: (1) plants inoculated with rhizobia and amended with sewage sludge at rate of 10% (w/w) (RS); (2) plants inoculated with rhizobia without any amendment (R); and (3) non-inoculated plants fed with ammonium nitrate (N). N2-fixing plants had lower growth and sucrose phosphate synthase activity but higher photosynthesis than nitrate-fed plants because they compensated the carbon cost of the rhizobia. However, sewage sludge-treated plants evidenced a loss of carbon sink strength due to N2 fixation by means of decreased photosynthetic capacity, leaf chlorophylls and N concentration in comparison to untreated plants. Sewage sludge did no affect nodulation but decreased nodule enzyme activities involved in carbon and N metabolisms that may lead to accumulation of toxic N-compounds.