Open Access
Inoculation with mycorrhizal fungi and irrigation management shaped the bacterial and fungal communities and networks in vineyard soils
(MDPI, 2021) Torres Molina, Nazareth; Yu, Runze; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Vineyard-living microbiota affect grapevine health and adaptation to changing environments and determine the biological quality of soils that strongly influence wine quality. However, their abundance and interactions may be affected by vineyard management. The present study was conducted to assess whether the vineyard soil microbiome was altered by the use of biostimulants (arbuscular mycorrhizal fungi (AMF) inoculation vs. non-inoculated) and/or irrigation management (fully irrigated vs. half irrigated). Bacterial and fungal communities in vineyard soils were shaped by both time course and soil management (i.e., the use of biostimulants and irrigation). Regarding alpha diversity, fungal communities were more responsive to treatments, whereas changes in beta diversity were mainly recorded in the bacterial communities. Edaphic factors rarely influence bacterial and fungal communities. Microbial network analyses suggested that the bacterial associations were weaker than the fungal ones under half irrigation and that the inoculation with AMF led to the increase in positive associations between vineyard-soil-living microbes. Altogether, the results highlight the need for more studies on the effect of management practices, especially the addition of AMF on cropping systems, to fully understand the factors that drive their variability, strengthen beneficial microbial networks, and achieve better soil quality, which will improve crop performance.
Open Access
Mycorrhizal symbiosis affects ABA metabolism during berry ripening in vitis vinifera L. cv. tempranillo grown under climate change scenarios
(Elsevier, 2018-06-19) Torres Molina, Nazareth; Goicoechea, Nieves; Zamarreño, Ángel M.; Antolín, M. Carmen; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Arbuscular mycorrhizal symbiosis is a promising tool for improving the quality of grapes under changing environments. Therefore, the aim of this research was to determine if the ability of arbuscular mycorrhizal fungi (AMF) to enhance phenolic content (specifically, anthocyanins) in a climate change framework could be mediated by alterations in berry ABA metabolism during ripening. The study was carried out on fruit-bearing cuttings of cv. Tempranillo (CL-1048 and CL-1089) inoculated (+M) or not (-M) with AMF. Two experimental designs were implemented. In the first experiment +M and -M plants were subjected to two temperatures (24/14°C or 28/18°C (day/night)) from fruit set to berry maturity. In the second experiment, +M and -M plants were subjected to two temperatures (24/14°C or 28/18°C (day/night)) combined with two irrigation regimes (late water deficit (LD) and full irrigation (FI)). At 28/18°C AMF contributed to an increase in berry anthocyanins and modulated ABA metabolism, leading to higher ABA-GE and 7'OH-ABA and lower phaseic acid (PA) in berries compared to -M plants. Under the most stressful scenario (LD and 28/18°C), at harvest +M plants exhibited higher berry anthocyanins and 7´OH-ABA and lower PA and dihydrophaseic acid (DPA) levels than -M plants. These findings highlight the involvement of ABA metabolism into the ability of AMF to improve some traits involved in the quality of grapes under global warming scenarios.
Open Access
Antioxidant properties of leaves from different accessions of grapevine (vitis vinifera L.) cv. tempranillo after applying biotic and/or environmental modulator factors
(Elsevier, 2015-01-17) Torres Molina, Nazareth; Antolín, M. Carmen; Goicoechea, Nieves; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Within climate change scenario, the maintenance of grape quality and wine characteristics will be the main concern for viticulture in the future years. However, changes in the composition of grapevine pruning wastes (i.e., leaves and stems) could be another interesting aspect as important antioxidant source for pharmaceutical industry due its richness in phenolic compounds beneficial for human health. To date, the effect of biotic and environmental factors in the accumulation of these compounds in leaves had received little attention. Therefore, the aims of study were (1) to evaluate the effect of biotic (mycorrhizal inoculation) and environmental (temperature) factors, alone or combined, on phenolic composition and antioxidant activity of leaf extracts of grapevine and (2) to determine whether such effects differed among accessions of the same cultivar of grapevine. The study was carried out using container-grown grapevines grown in greenhouses. Dormant Vitis vinifera (L.) cuttings of different accessions of Tempranillo were selected to get fruit-bearing cuttings. At transplanting, half of the plants of each accession were inoculated with the mycorrhizal inoculum and after fruit set, plants were exposed to two temperature regimes (24 °C/14 °C and 28 °C/18 °C (day/night)) to commercially berry ripe. Results showed that total phenolic content, antioxidant compounds like flavonols and anthocyanins, and antioxidant activity of leaves were improved with mycorrhizal inoculation under high temperature conditions. It was concluded that mycorrhizal inoculation of grapevines could contribute to preserve high level of antioxidant compounds of leaves in a future climate change scenario. However, the effects were strongly dependent of accession assayed, which indicated a significant intra-varietal diversity in the response of Tempranillo to biotic and environmental factors.
Open Access
Effects of irrigation at different fractions of crop evapotranspiration on water productivity and flavonoid composition of Cabernet Sauvignon grapevine
(Frontiers Media, 2021) Torres Molina, Nazareth; Yu, Runze; Martínez-Lüscher, Johann; Kostaki, Evmorfia; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Climate change models predict lower precipitation and higher air temperatures that will negatively affect viticultural regions. Irrigation of vineyards will be crucial for mitigating abiotic stress during the growing season. However, the environmental impact of irrigation requires consideration for ensuring its sustainability in the future. We evaluated the standard irrigation practices on grapevine water use efficiency, berry flavonoid composition, vineyard water footprint, and arbuscular mycorrhizal fungi-grapevine symbiosis in two seasons with contrasting amounts of precipitation. The irrigation treatments consisted of weekly replacement of 25, 50, and 100% of crop evapotranspiration (ETc) during two growing seasons. Irrigation in grapevine vineyards mitigated the water scarcity when precipitation during the dormant season was not sufficient. The results provided field data supporting that despite the low rainfall recorded in one of the seasons, increasing the amount of irrigation was not advised, and replacing 50% ETc was sufficient. In this treatment, berry composition was improved with increased contents of total soluble solids, anthocyanins, and flavonols, and a stable flavonoid profile without an economic decrease in yield. In addition, with 50% ETc, the mycorrhizal symbiosis was not compromised and water resources were not highly impacted. Altogether, our results provide fundamental knowledge for viticulturists to design an appropriate irrigation schedule under the future warming scenarios with minimal environmental impact in semi-arid regions facing warming trends.
Open Access
Arbuscular mycrorrhizal fungi inoculation and applied water amounts modulate the response of young grapevines to mild water stress in a hyper-arid season
(Frontiers Media, 2021-01-14) Torres Molina, Nazareth; Yu, Runze; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Several factors may affect the success of a replanting vineyard. Given the current environmental conditions, an optimized irrigation schedule would still be one of the most desirable tools to improve crop productivity and fruit quality. On the other hand, the symbiosis of grapevines with arbuscular mycorrhizal fungi (AMF) is a key component of the vineyard production systems improving the vine growth, nutrient uptake, and berry quality. The aim of this study was to characterize the response of Merlot grapevines to AMF inoculation and two different irrigation amounts in their first productive year. The experiment was conducted on 2-year Merlot grapevines inoculated with AMF (I) or not-inoculated (NI) and subjected to two irrigation amounts, full irrigated (FI), where the amount of water was enough to maintain expansive growth and half irrigated (HI) where plants received the half of the amount of water of FI plants. Water status, gas exchange parameters, growth, mineral content, berry composition, and mycorrhizal colonization were monitored through the season. AMF inoculation improved the grapevine vegetative growth, water status, and photosynthetic activity, especially when vines were subjected to HI irrigation; however, no effect was observed on the leaf mineral content, must pH, total soluble solids, or total acidity. The main effects were observed on the flavonoid composition of berry skins at harvest. Irrigation amounts and mycorrhizal inoculation modified cyanidin and peonidin derivatives whereas flavonol composition was mainly affected by irrigation treatments. A strong relationship between the mycorrhizal colonization rate of roots and total quercetins, cyanidins, and peonidins was found. Findings support the use of a mycorrhizal inoculum and a better water management in a hyper-arid growing season; however, these results may be affected by edaphoclimatic characteristics and living microbiota in vineyard soils, which should be taken into account before making the decision of inoculating the vineyard.