Secondary metabolites in grapevine: crosstalk of transcriptional, metabolic and hormonal signals controlling stress defence responses in berries and vegetative organs

Abiotic stresses, such as temperature, heat waves, water limitation, solar radiation and the increase in atmospheric CO concentration, significantly influence the accumulation of secondary metabolites in grapevine berries at different developmental stages, and in vegetative organs. Transcriptional reprogramming, miRNAs, epigenetic marks and hormonal crosstalk regulate the secondary metabolism of berries, mainly the accumulation of phenylpropanoids and of volatile organic compounds (VOCs). Currently, the biological mechanisms that control the plastic response of grapevine cultivars to environmental stress or that occur during berry ripening have been extensively studied in many worlds viticultural areas, in different cultivars and in vines grown under various agronomic managements. A novel frontier in the study of these mechanisms is the involvement of miRNAs whose target transcripts encode enzymes of the flavonoid biosynthetic pathway. Some miRNA-mediated regulatory cascades, post-transcriptionally control key MYB transcription factors, showing, for example, a role in influencing the anthocyanin accumulation in response to UV-B light during berry ripening. DNA methylation profiles partially affect the berry transcriptome plasticity of different grapevine cultivars, contributing to the modulation of berry qualitative traits. Numerous hormones (such as abscisic and jasmomic acids, strigolactones, gibberellins, auxins, cytokynins and ethylene) are involved in triggering the vine response to abiotic and biotic stress factors. Through specific signaling cascades, hormones mediate the accumulation of antioxidants that contribute to the quality of the berry and that intervene in the grapevine defense processes, highlighting that the grapevine response to stressors can be similar in different grapevine organs. The expression of genes responsible for hormone biosynthesis is largely modulated by stress conditions, thus resulting in the numeourous interactions between grapevine and the surrounding environment

The short term influence of aboveground biomass cover crops on C sequestration and β-glucosidase in a vineyard ground under semiarid conditions

© 2014 Ministerio de Agricultura Pesca y Alimentacion. All Rights Reserved. Tillage and semiarid Mediterranean climatic conditions accelerate soil organic matter losses in Spanish vineyards. Previous studies showed that cover crops can increase soil organic carbon (SOC) in Mediterranean vineyards. The objectives of this study were to evaluate the influence of two different cover crops in the short term on soil C sequestration in a semiarid vineyard and to study the potential use of both β-glucosidase enzimatic activity (GLU) and the GLU/SOC ratio in order to assess the SOC increase. The experiment was carried out in a cv. Tempranillo (Vitis vinifera L.) vineyard on a Oxyaquic Xerorthent soil in Rioja winegrowing region (NE, Spain). The experimental design was established in 2009 with three treatments: conventional tillage; sown barley cover crop (Hordeum vulgare, L.); sown Persian clover cover crop (Trifolium resupinatum L.). Carbon in the aboveground biomass with each cover crop was monitored. Soil was sampled in June 2011 and June 2012, and SOC, GLU and the GLU/SOC ratio were determined. After 3 years both cover crops increased SOC at soil surface with C sequestration rates of 0.47 and 1.19 t C ha–1 yr–1 for BV and CV respectively. GLU and GLU/SOC ratio increased in both cover crops at 0-5 cm soil depth. The C sequestration rates and GLU were related to the cover crops aboveground biomass. In consequence, in semiarid vineyards under cover crops GLU could be an appropriate indicator to asses the increase of SOC and the soil quality improvement in the short-term (2-3 years).This study was supported by the Spanish Ministry of Science, INIA and European Social Fund through project INIA-RTA 2009-00101-00-00. F. Peregrina thanks the INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria) and European Social Fund for its post-doctoral grants and E. Pérez-Álvarez thanks the INIA for her pre-doctoral grant.Peer Reviewe

Ecophysiological responses of grapevine rootstocks to water deficit

The use of rootstocks tolerant to soil water deficit is an interesting strategy to face the challenges posed by limited water availability. Currently, several nurseries are breeding new genotypes aiming to improve the water stress tolerance of grapevine, but the physiological basis of its responses under water stress are largely unknown. For this purpose, an ecophysiological assessment of the conventional 110-Richter (110R) and SO4, and the new M1 and M4 rootstocks was carried out in ungrafted potted plants. During one season, these Vitis genotypes were grown under greenhouse conditions and subjected to two water regimes, well-watered (WW) and deficit irrigation (DI). Water potentials of plants under DI down to <-1.4 MPa, and net photosynthesis (AN) <5 μmol CO2m-2s-1 did not cause leaf oxidative stress damage compared to WW conditions in all genotypes. The antioxidant capacity was sufficient to neutralize the mild oxidative stress suffered. Under both water regimes, gravimetric differences in daily water use were observed among genotypes, leading to differences in the biomass of roots and shoots. Under WW conditions, SO4 and 110R were the most vigorous and M1 and M4 the least. However, under DI, SO4 exhibited the greatest reduction in biomass, while 110R showed the lowest. Remarkably, under these conditions, SO4 reached the least negative stem water potential and showed the highest hydraulic conductance values. Conversely, M1 reduced the most stomatal conductance, transpiration and AN. Overall, 110R achieved the highest biomass water use efficiency in response to DI, and SO4 the lowest, while M-rootstocks showed intermediate values. Our results suggest that there are differences in water use regulation among genotypes attributed not only to differences in stomatal regulation but also to plant hydraulic conductance. Therefore, it is hypothesized that differences in genotype performance may be due to root anatomical- morphological differences and to several physiological processes such as growth inhibition, osmotic adjustment, antioxidant production, nutrient translocation capacity, etc. Further studies are needed to confirm these differential ecophysiological responses of Vitis species under water stress, particularly under field and grafted conditions

Explorando el potencial bioestimulante del alga invasora Rugulopterix okamurae en vid

Trabajo presentado en las IV Jornadas del Grupo de Viticultura de la Sociedad Española de Ciencias Hortícolas, celebradas en Pamplona (España), del 26 al 28 de octubre de 202

Blastic plasmacytoid dendritic cell neoplasm frequently shows occult central nervous system involvement at diagnosis and benefits from intrathecal therapy

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare aggressive myeloid neoplasm which shows a high rate of central nervous system (CNS) recurrence and overall survival (OS) of <1 year. Despite this, screening for CNS involvement is not routinely performed at diagnosis and intrathecal (IT) prophylaxis is not regularly administered in BPDCN. Here, we prospectively evaluated 13 consecutive BPDCN patients for the presence of CNS involvement by flow cytometry. Despite none of the patients presented with neurological symptoms, occult CNS involvement was detected in 6/10 cases evaluated at diagnosis and 3/3 studied at relapse/progression. BPDCN patients evaluated at diagnosis received IT treatment -either CNS prophylaxis (n = 4) or active therapy (n = 6)- and all but one remain alive (median follow-up of 20 months). In contrast, all three patients assessed at relapse/progression died. The potential benefit of IT treatment administered early at diagnosis on OS and CNS recurrence-free survival of BPDCN was further confirmed in a retrospective cohort of another 23 BPDCN patients. Our results show that BPDCN patients studied at diagnosis frequently display occult CNS involvement; moreover, they also indicate that treatment of occult CNS disease might lead to a dramatically improved outcome of BPDCN

SARS-CoV-2 Infection and C-Section: A Prospective Observational Study

Pregnant women are particularly vulnerable to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In addition to unfavorable perinatal outcomes, there has been an increase in obstetric interventions. With this study, we aimed to clarify the reasons, using Robson's classification model, and risk factors for cesarean section (C-section) in SARS-CoV-2-infected mothers and their perinatal results. This was a prospective observational study that was carried out in 79 hospitals (Spanish Obstetric Emergency Group) with a cohort of 1704 SARS-CoV-2 PCR-positive pregnant women that were registered consecutively between 26 February and 5 November 2020. The data from 1248 pregnant women who delivered vaginally (vaginal + operative vaginal) was compared with those from 456 (26.8%) who underwent a C-section. C-section patients were older with higher rates of comorbidities, in vitro fertilization and multiple pregnancies (p < 0.05) compared with women who delivered vaginally. Moreover, C-section risk was associated with the presence of pneumonia (p < 0.001) and 41.1% of C-sections in patients with pneumonia were preterm (Robson's 10th category). However, delivery care was similar between asymptomatic and mild-moderate symptomatic patients (p = 0.228) and their predisposing factors to C-section were the presence of uterine scarring (due to a previous C-section) and the induction of labor or programmed C-section for unspecified obstetric reasons. On the other hand, higher rates of hemorrhagic events, hypertensive disorders and thrombotic events were observed in the C-section group (p < 0.001 for all three outcomes), as well as for ICU admission. These findings suggest that this type of delivery was associated with the mother's clinical conditions that required a rapid and early termination of pregnancy.This project was supported by public funds that were obtained in competitive calls: Grant COV20/00021 (EUR 43,000 from the Instituto de Salud Carlos III-Spanish Ministry of Health) and co-financed with Fondo Europeo de Desarrollo Regional (FEDER) funds

Holistic understanding of the response of grapevines to foliar application of seaweed extracts

Viticulture is highly dependent on phytochemicals to maintain good vineyard health. However, to reduce their accumulation in the environment, green regulations are driving the development of eco-friendly strategies. In this respect, seaweeds have proven to be one of the marine resources with the highest potential as plant protective agents, representing an environmentally-friendly alternative approach for sustainable wine production. The current work follows an interdisciplinary framework to evaluate the capacity of Ulva ohnoi and Rugulopteryx okamurae seaweeds to induce defense mechanisms in grapevine plants. To our knowledge, this is the first study to evaluate Rugulopteryx okamurae as a biostimulator . This macroalgae is relevant since it is an invasive species on the Atlantic and Mediterranean coast causing incalculable economic and environmental burdens. Four extracts (UL1, UL2, RU1 and RU2 developed from Ulva and Rugulopteryx, respectively) were foliar applied to Tempranillo plants cultivated under greenhouse conditions. UL1 and RU2 stood out for their capacity to induce defense genes, such as a PR10, PAL, STS48 and GST1, mainly 24 hours after the first application. The increased expression level of these genes agreed with i) an increase in trans-piceid and trans-resveratrol content, mainly in the RU2 treated leaves, and, ii) an increase in jasmonic acid and decrease in salicylic acid. Moreover, an induction of the activity of the antioxidant enzymes was observed at the end of the experiment, with an increase in superoxide dismutase and catalase in the RU2-treated leaves in particular. Interestingly, while foliar fungal diversity was not influenced by the treatments, alga extract amendment modified fungal composition, RU2 application enriching the content of various groups known for their biocontrol activity. Overall, the results evidenced the capacity of Rugulopteryx okamurae for grapevine biostimulation, inducing the activation of several secondary metabolite pathways and promoting the abundance of beneficial microbiota involved in grapevine protection. While further studies are needed to unravel the bioactive compound(s) involved, including conducting field experiments etc., the current findings are the first steps towards the inclusion of Rugulopteryx okamurae in a circular scheme that would reduce its accumulation on the coast and benefit the viticulture sector at the same time