XIII Simposio Hispano-Portugués de Relaciones Hídricas en las Plantas

The effect of water stress on grape berry ripening and quality has been extensively investigated during the last decades (Chaves et al., 2010; Lovisolo et al., 2010; Kuhn et al., 2013, Zarrouk et al., 2016). Overall, berry quality benefits from mild to moderate water deficit and the conventional wisdom says that the observed positive effects of water deficits are due to low yield and small berries. But more recently water deficit was shown to profoundly alter berry secondary metabolism, particularly of flavonoids, thus greatly regulating the ripening process. The regulation of genes and proteins of the various metabolic pathways is either the consequence of a direct effect of water shortage and/or indirect via the changing of the light environment around grape clusters due to the impairment of vine vegetative growth. The matter is far from being conclusively addressed and two major causes can be highlighted: the experimental set-ups adopted in the majority of experiments, namely the water stress timing and conditions (pre- or post-véraison water stress); and the diversity of varieties (Zarrouk et al., 2016). Grape berries are non-climacteric fruits wherein abscisic acid (ABA) is central to the ripening process. The differential increase of anthocyanin compounds in berries under pre- or post-véraison deficit irrigation is primarily attributed to large differences in abscisic acid (ABA) sensitivity displayed by different varieties as a consequence of large differences in the ability to regulate water losses through chemical (i.e. ABA) signaling. Grape berries thus represent a unique situation in which abiotic stress and developmental signaling intersect via the activities of ABA. In addition, climate condition, namely high temperature along the growing season is considered a putative constraint to the implementation and success of the deficit irrigation regime. Also the interaction elevated temperature – water deficit is considered as the main cause of complexity of field experiments results namely in what concerns the ripening of wine grapes. During the last ten years, our investigation aimed to comprehend the impact of water stress and heat stress on grape berry ripening, skin secondary metabolism as well as cuticle properties. We have investigated ABA-mediated cross talk between abiotic stress and ripening as it relates to flavonoid biosynthesis in the grape berry skin. We show that the mild XIII Simposio Hispano-Portugués de Relaciones Hídricas en las Plantas: Pamplona 18-20 Octubre 2016 7 stress imposed by deficit irrigation have a positive impact on berry composition only when high temperature is not a limiting factor. We also show that the biological function of ABA is under berry developmental control and does not correlate with vine water status or berry temperature until a certain water stress threshold. It also appears that ABA catabolism/conjugation processes are implicated in the ripening process and in water and heat stresses responses. In addition, our most recent results in cuticle indicate that water and heat stresses increase berry wax accumulation across berry development, affecting cuticle morphology, composition and transpiration. The recent data related to metabolic changes and hormonal control of grape berry ripening as well as berry cuticle properties under deficit irrigation will be discussed and limitations in the interpretation of results will be identified

Arbuscular mycorrhizal symbiosis as a promising resource for Improving berry quality in grapevines under changing environments

Climate change and their resulting impacts are becoming a concern for winegrowers due to the high socioeconomic relevance of the winemaking sector worldwide. In fact, the projected climate change is expected to have detrimental impacts on the yield of grapevines, as well as on the quality and properties of grapes and wine. It is well known that arbuscular mycorrhizal fungi (AMF) can improve the nutritional quality of edible parts of crops and play essential roles in the maintenance of host plant fitness under stressed environments, including grapevines. The future scenarios of climate change may also modify the diversity and the growth of AMF in soils as well as the functionality of the mycorrhizal symbiosis. In this review, we summarize recent research progress on the effects of climate change on grapevine metabolism, paying special attention to the secondary compounds involved in the organoleptic properties of grapes and wines and to the levels of the phytohormones implied in the control of berry development and fruit ripening. In this context, the potential role of AMF for maintaining fruit quality in future climate change scenarios is discussed

Aminoacids and flavonoids profiling in tempranillo berries can be modulated by the arbuscular mychorrhizal fungi

(1) Background: Vitis vinifera L. cv. Tempranillo is cultivated over the world for its wine of high quality. The association of Tempranillo with arbuscular mycorrhizal fungi (AMF) induced the accumulation of phenolics and carotenoids in leaves, affected the metabolism of abscisic acid (ABA) during berry ripening, and modulated some characteristics and quality aspects of grapes. The objective of this study was to elucidate if AMF influenced the profiles and the content of primary and secondary metabolites determinants for berry quality in Tempranillo. (2) Methods: Fruit-bearing cuttings inoculated with AMF or uninoculated were cultivated under controlled conditions. (3) Results: Mycorrhizal symbiosis modified the profile of metabolites in Tempranillo berries, especially those of the primary compounds. The levels of glucose and amino acids clearly increased in berries of mycorrhized Tempranillo grapevines, including those of the aromatic precursor amino acids. However, mycorrhizal inoculation barely influenced the total amount and the profiles of anthocyanins and flavonols in berries. (4) Conclusions: Mycorrhizal inoculation of Tempranillo grapevines may be an alternative to the exogenous application of nitrogen compounds in order to enhance the contents of amino acids in grapes, which may affect the aromatic characteristics of wines

Dissimilar esponses of ancient grapevines recovered in Navarra (Spain) to arbuscular mycorrhizal symbiosis in terms of berry quality

The exploitation of genetic diversity within agricultural plants, including grapevine, is suggested as a valuable tool to cope with the negative impacts of climate change on yield and crop quality. In some winegrowing regions of Europe, there is a renewed interest in knowing the grapevine genetic resources available, focusing on the prospection, recovery, and study of ancient cultivars typical of every zone. Grapevines are naturally associated with arbuscular mycorrhizal fungi (AMF), which provide some benefits to the host plant, although such effects depending on many factors, including variety. Therefore, the aim of this research was to characterize the potential fruit quality of eight old grapevine varieties recovered in Navarre (northeastern of the Iberian Peninsula), associated or not with AMF. The study was carried out on fruit-bearing cuttings grown under controlled conditions (greenhouse). Overall, AMF inoculation reduced bunch and berry mass, as well as phenolic content in fruits. In some varieties, AMF association improved some berry traits by increasing the concentrations of soluble solids and anthocyanins; in others, berry colour, total phenolic and anthocyanin content were diminished in AMF-inoculated plants. The results, therefore, suggest that intraspecific diversity of old grapevines could include different abilities to respond to arbuscular mycorrhizal symbiosis

Application of different doses of compost as a substitution of the commercial substrate in nursery for pepper and tomato seedlings

Purpose The decreasing number of peatlands has driven the search for new cultivation substrates. The aim of this study was to evaluate the use of different composts as growing media in the production of vegetable seedlings (pepper and tomato). Method Composts were produced from: discarded carrots (ZC), fats (FC), and biosolids (BC) from the dairy industry. They were used as peat substitutes in different doses depending on the germinating species: control (CS-commercial substrate) and three growing media prepared with perlite: 25, 35, and 45% of ZC, FC, and BC for pepper seedlings and 40, 55 and 70% of ZC, FC, and BC for tomato seedlings. When the plants were ready for transplantation they were harvested and the data were collected to assess the development of the seedlings in the different growth media. Results The obtained results suggest the possibility of total substitution of the CS by ZC, FC, and BC to produce pepper and tomato plants in commercial nurseries. The plants cultivated with composts presented higher concentrations of total dry matter compared to the controls. Photosynthetic pigments were affected by the presence of FC and BC, whereas TSP concentration was favored by BC. Conclusion Ours results suggest that it is feasible to perform a total substitution of commercial substrates with composts of different origins and compositions for the production of pepper and tomato plants in commercial nurseries

Prospecting the resilience of several Spanish ancient varieties of red grape under climate change scenarios

Background: Climate change results in warmer air temperatures and an uncertain amount and distribution of annual precipitations, which will directly impact rainfed crops, such as the grapevine. Traditionally, ancient autochthones grapevine varieties have been substituted by modern ones with higher productivity. However, this homogenization of genotypes reduces the genetic diversity of vineyards which could make their ability to adapt to challenges imposed by future climate conditions difficult. Therefore, this work aimed to assess the response of four ancient grapevine varieties to high temperatures under different water availabilities, focusing on plant water relations, grape technological and phenolic maturity, and the antioxidant capacity of the must. Methods: The study was conducted on fruit-bearing cuttings grown in pots in temperature-gradient greenhouses. A two-factorial design was established where two temperature regimes, ambient and elevated (ambient + 4 °C), were combined with two water regimes, full irrigation and post-veraison deficit irrigation, during fruit ripening. Results: There were significant differences among the ancient varieties regarding plant water relations and fruit quality. Conclusion: This research underlines the importance of evaluating the behavior of ancient grapevine varieties that could offer good options for the adaptation of viticulture to future climate condition

Novel, technical advance: a new grapevine transpiration prototype for grape berries and whole bunch based on relative humidity sensors

Grape berry transpiration is considered an important process during maturation, but scientific evidence is scarce. In the literature, there is only one report showing reduced maturation when bunch transpiration is artificially slowed down. Traditionally, grape berry transpiration has been measured by weighing grape berries on scale for a given time, correctly assuming that the weight reduction is due to water lost. Commercially available instruments adequate to measure gas exchange in small fruits are not suitable for whole grape berry bunch. Here, we present an open differential chamber system that can be used with isolated grape berries or alternatively with a whole grape berry bunch for measuring grape berry/bunch transpiration based on the use of relative humidity sensors from Vaisala. When used with isolated grape berries, open differential chamber system validation was made by using Tempranillo grape berries collected at different phenological stages. For the whole bunch transpiration prototype, two different validations were made. Firstly, measurements were made inserting inside the chamber an increasing number of Eppendorf tubes filled with water. Secondly, transpiration was measured in whole Tempranillo bunches sampled at different phenological stages. An important output of this work is that the fact of detaching the bunch from the plant did not change the bunch gas exchange rates at least for several hours

Arbuscular mycorrhizal symbiosis as a promising resource for Improving berry quality in grapevines under changing environments

Climate change and their resulting impacts are becoming a concern for winegrowers due to the high socioeconomic relevance of the winemaking sector worldwide. In fact, the projected climate change is expected to have detrimental impacts on the yield of grapevines, as well as on the quality and properties of grapes and wine. It is well known that arbuscular mycorrhizal fungi (AMF) can improve the nutritional quality of edible parts of crops and play essential roles in the maintenance of host plant fitness under stressed environments, including grapevines. The future scenarios of climate change may also modify the diversity and the growth of AMF in soils as well as the functionality of the mycorrhizal symbiosis. In this review, we summarize recent research progress on the effects of climate change on grapevine metabolism, paying special attention to the secondary compounds involved in the organoleptic properties of grapes and wines and to the levels of the phytohormones implied in the control of berry development and fruit ripening. In this context, the potential role of AMF for maintaining fruit quality in future climate change scenarios is discussed

Influencia de la inoculación micorrícica sobre la composición fenólica y la capacidad antioxidante de la vid (Vitis Vinifera L.) CV. Tempranillo en diferentes escenarios del cambio climático

The foreseen climate change is going to affect the agricultural suitability, viticulture being one of those sectors more sensible to environmental constraints. Projected warming combined with severe droughts in the growing season is expected to have detrimental impacts on the grape berry ripening affecting the berry quality. Thus, the demonstrated intra-varietal diversity of cv. Tempranillo has led to the search of new clones able to cope with the projected scenarios. On the other hand, new strategies such as deficit irrigation of vineyards have emerged as a promising tool to withstand water stress in this new challenging scenario. Also, the promotion of the symbiotic association of grapevines with arbuscular mycorrhizal fungi (AMF) which are known to benefit host plants by improving nutrient uptake, growth and water status of grapevines and helping them to cope with abiotic stresses. However, less is known about their effect on the phenolic content and antioxidant properties under climate change scenarios as well as, the role that plant hormones, which interact to regulate the establishment and functioning of symbiotic associations with AMF, play under abovementioned conditions. Besides, the cultivation of grapevines produced a huge amount of pruning wastes which could be reused in the pharmaceutical and nutritional industries due to their elevated content in nutraceuticals and antioxidant metabolites. Again, the role of AMF on the primary and secondary metabolism of grapevine leaves under elevated temperature remains unclear. Taking all into account the general objective of this PhD thesis was to assess the intra-varietal diversity of grapevine cv. Tempranillo to respond to different climate change scenarios (elevated air temperature and deficit irrigation) and to analyze if the potential benefits of mycorrhizal symbiosis on plant metabolism could be maintained under the predicted environmental conditions. The study was carried out on fruit-bearing cuttings clones of cv. Tempranillo with different agronomic traits and origins (CL-260, CL-1048, CL-1089, CL-8, CL-280 and CL-843) inoculated (+M) or not (−M) with AMF and grown under controlled conditions. Plants were subjected to two temperature regimes (24/14°C and 28/18°C (day/night)) from fruit set to berry maturity and different irrigation regimes (early season deficit irrigation, ED; late season deficit irrigation, LD; and full irrigation, FI) throughout berry development. This dissertation provided evidence of the broad diversity within Tempranillo variety highlighting the importance of an appropriate clonal selection based on the plausible applications and/or the environmental or biotic modulator factors and demonstrates the importance of adopting measures to protect the indigenous cohorts of AMF in vineyards. Moreover, since each clone responded differently to each mycorrhizal inoculum and responses varied according to the environmental conditions, it may be profitable to identify the AMF inoculants most suitable for a given clone in a given environment

Influencia de la inoculación micorrícica sobre la composición fenólica y la capacidad antioxidante de la vid (Vitis Vinifera L.) CV. Tempranillo en diferentes escenarios del cambio climático

The foreseen climate change is going to affect the agricultural suitability, viticulture being one of those sectors more sensible to environmental constraints. Projected warming combined with severe droughts in the growing season is expected to have detrimental impacts on the grape berry ripening affecting the berry quality. Thus, the demonstrated intra-varietal diversity of cv. Tempranillo has led to the search of new clones able to cope with the projected scenarios. On the other hand, new strategies such as deficit irrigation of vineyards have emerged as a promising tool to withstand water stress in this new challenging scenario. Also, the promotion of the symbiotic association of grapevines with arbuscular mycorrhizal fungi (AMF) which are known to benefit host plants by improving nutrient uptake, growth and water status of grapevines and helping them to cope with abiotic stresses. However, less is known about their effect on the phenolic content and antioxidant properties under climate change scenarios as well as, the role that plant hormones, which interact to regulate the establishment and functioning of symbiotic associations with AMF, play under abovementioned conditions. Besides, the cultivation of grapevines produced a huge amount of pruning wastes which could be reused in the pharmaceutical and nutritional industries due to their elevated content in nutraceuticals and antioxidant metabolites. Again, the role of AMF on the primary and secondary metabolism of grapevine leaves under elevated temperature remains unclear. Taking all into account the general objective of this PhD thesis was to assess the intra-varietal diversity of grapevine cv. Tempranillo to respond to different climate change scenarios (elevated air temperature and deficit irrigation) and to analyze if the potential benefits of mycorrhizal symbiosis on plant metabolism could be maintained under the predicted environmental conditions. The study was carried out on fruit-bearing cuttings clones of cv. Tempranillo with different agronomic traits and origins (CL-260, CL-1048, CL-1089, CL-8, CL-280 and CL-843) inoculated (+M) or not (−M) with AMF and grown under controlled conditions. Plants were subjected to two temperature regimes (24/14°C and 28/18°C (day/night)) from fruit set to berry maturity and different irrigation regimes (early season deficit irrigation, ED; late season deficit irrigation, LD; and full irrigation, FI) throughout berry development. This dissertation provided evidence of the broad diversity within Tempranillo variety highlighting the importance of an appropriate clonal selection based on the plausible applications and/or the environmental or biotic modulator factors and demonstrates the importance of adopting measures to protect the indigenous cohorts of AMF in vineyards. Moreover, since each clone responded differently to each mycorrhizal inoculum and responses varied according to the environmental conditions, it may be profitable to identify the AMF inoculants most suitable for a given clone in a given environment