Foliar application of nettle and Japanese knotweed extracts on Vitis vinifera: impact on phenylpropanoid biosynthesis and antioxidant activity during veraison and harvest of cv. Touriga Franca

BACKGROUND

Plant-based extracts have been recently used as sustainable tools to improve biotic and abiotic stress tolerance and increase grape (Vitis vinifera L.) quality. However, knowledge about the effect of these extracts on secondary metabolism compounds, that are fundamental for grape and wine quality, is still scarce. In this study, a trial was installed in an experimental vineyard with the variety Touriga Franca located at University of Trás-os-Montes e Alto Douro, Baixo Corgo sub-region of the Douro Demarcated Region, Portugal in two growing seasons: 2019 and 2020. The aim was to evaluate the effect of foliar application of nettle (Urtica spp.) extract (NE) and Japanese knotweed (Reynoutria japonica) extract (JKE) on grapevines leaves and berries bioactive compounds contents and antioxidant activity, at veraison and harvest.

RESULTS

The application of NE increased the total carotenoids in leaves and the total phenolics content and the antioxidant activity (ferric reducing antioxidant power, FRAP) in berries while JKE increased flavonoids content in leaves and the antioxidant activity (2,2-diphenyl-1-picrylhydrazyl, DPPH) in berries.

CONCLUSION

These extracts seem to have a stimulatory effect on grapevine, enhancing bioactive compounds contents and antioxidant capacity and, consequently, the physiological performance of the plant and the quality of the berries. © 2024 Society of Chemical Industry.

Ascophyllum nodosum Extract and Glycine Betaine Preharvest Application in Grapevine: Enhancement of Berry Quality, Phytochemical Content and Antioxidant Properties

The Douro Demarcated Region (DDR) has peculiar edaphoclimatic characteristics that provide a suitable terroir for premium wine production. As climate change effects continue to emerge, ensuring productivity and quality becomes increasingly important for viticulturists, as those directly determine their profits. Cultural approaches, such as the use of biostimulants, are actively being developed to mitigate abiotic stress. The main objective of this work was to assess the effect of foliar sprays of a seaweed (Ascophyllum nodosum)-based extract (ANE) and glycine betaine (GB) on grape berry quality, bioactive compounds, and antioxidant activity. A trial was installed in a commercial vineyard (cv. 'Touriga Franca') in the Douro Superior (Upper Douro) sub-region of the Douro Demarcated Region. In 2020 and 2021, three foliar sprayings were performed during the growing season, namely at pea size, bunch closure, and veraison. There was a positive effect of both biostimulants (ANE and GB) on the physiological and biochemical performance of cv. 'Touriga Franca' exposed to summer stress. In general, the GB 0.2% spraying was the most promising treatment for this grape cultivar, as it increased berry quality, the concentration of bioactive compounds (total phenolics, flavonoids, and ortho-diphenols), and the antioxidant activity. These results revealed the efficacy of biostimulant sprayings as a sustainable viticultural practice, improving berry quality under summer stress conditions.

Hydropriming and Nutripriming of Bread Wheat Seeds Improved the Flour's Nutritional Value of the First Unprimed Offspring

Seed hydropriming or nutripriming has been used for wheat biofortification. Previously, the untreated S1 offspring of bread wheat S0 seeds hydro- and nutriprimed with FeSO₄.7H₂O and/or ZnSO₄.7H₂O showed improved yield relative to the offspring of untreated S0 seeds. We hypothesize that such improvement would have its origin in the higher quality of S1 seeds resulting from plants whose seeds were primed. In this work, we characterised biochemically the whole-wheat flour of unprimed S1 offspring whose S0 seeds were hydro- and nutriprimed with Fe and/or Zn and compared it to the offspring of untreated S0 seeds (control). We identified and quantified 16 free amino acids and five soluble sugars per offspring using high-performance liquid chromatography and the Association of Official Analytical Chemists (AOAC) methods. The most abundant amino acids were glutamic acid and glutamine, proline, and glycine, presenting their highest contents in the offspring of seeds nutriprimed with 8 ppm Zn (0.351 mmol∙g^-1), 8 ppm Fe + 8 ppm Zn (0.199 mmol∙g^-1), and (0.135 mmol∙g^-1), respectively. The highest contents of glucose (1.91 mg∙g^-1 sample), ash (24.90 g∙kg^-1 dry matter, DM), and crude protein (209.70 g∙kg^-1 DM) were presented by the offspring resulting from 4 ppm Fe + 4 ppm Zn, 8 ppm Zn, and 8 ppm Fe + 8 ppm Zn, respectively. The highest total starch content (630.10 g∙kg^-1 DM) was detected in the offspring of seeds soaked in 8 ppm Fe. The nutritional value of the flour of the S1 offspring resulting from nutripriming was significantly higher than the control. Overall, the novelty of our research is that seed priming can improve the quality of the wheat grain and flour, at least till the first offspring, without the need to repeat the presowing treatment. Beyond the study of subsequent generations, the unravelling of transgenerational mechanisms underlying the biochemical improvement of the offspring is approached.

Correspondence Rules for SU(1,1) Quasidistribution Functions and Quantum Dynamics in the Hyperbolic Phase Space

We derive the explicit differential form for the action of the generators of the SU(1,1) group on the corresponding s-parametrized symbols. This allows us to obtain evolution equations for the phase-space functions on the upper sheet of the two-sheet hyperboloid and analyze their semiclassical limits. Dynamics of quantum systems with SU(1,1) symmetry governed by compact and non-compact Hamiltonians are discussed in both quantum and semiclassical regimes.

Recent Advances in the Molecular Effects of Biostimulants in Plants: An Overview

As the world develops and population increases, so too does the demand for higher agricultural output with lower resources. Plant biostimulants appear to be one of the more prominent sustainable solutions, given their natural origin and their potential to substitute conventional methods in agriculture. Classified based on their source rather than constitution, biostimulants such as humic substances (HS), protein hydrolysates (PHs), seaweed extracts (SWE) and microorganisms have a proven potential in improving plant growth, increasing crop production and quality, as well as ameliorating stress effects. However, the multi-molecular nature and varying composition of commercially available biostimulants presents challenges when attempting to elucidate their underlying mechanisms. While most research has focused on the broad effects of biostimulants in crops, recent studies at the molecular level have started to unravel the pathways triggered by certain products at the cellular and gene level. Understanding the molecular influences involved could lead to further refinement of these treatments. This review comprises the most recent findings regarding the use of biostimulants in plants, with particular focus on reports of their molecular influence.

Eye contact effects on social preference and face recognition in normal ageing and in Alzheimer's disease

Perceiving a direct gaze (i.e. another individual's gaze directed to the observer leading to eye contact) influences positively a wide range of cognitive processes. In particular, direct gaze perception is known to stimulate memory for other's faces and to increase their likeability. Alzheimer's disease (AD) results in social withdrawal and cognitive decline. However, patients show preserved eye contact behaviours until the middle stage of the disease. The eye contact effects could be preserved in AD and be used to compensate for cognitive and social deficits. Yet, it is unknown whether these effects are preserved in normal ageing. The aim of this study was to address whether the positive effects of eye contact on memory for faces and likeability of others are preserved in healthy older adults and in patients with early to mild AD. Nineteen AD patients, 20 older adults and 20 young adults participated in our study. Participants were first presented with faces displaying either direct or averted gaze and rated each face's degree of likeability. They were then asked to identify the faces they had previously seen during a surprise recognition test. Results showed that the effect of eye contact on other's likeability was preserved in normal ageing and in AD. By contrast, an effect of eye contact on memory for faces seems to emerge only in young participants, suggesting that this effect declines with ageing. Interestingly, however, AD patients show a positive correlation between ratings of likeability and recognition scores, suggesting that they implicitly allocated their encoding resources to most likeable faces. These results open a new way for a "compensating" therapy in AD.

[Eye contact effects: A therapeutic issue?]

INTRODUCTION

The perception of a direct gaze - that is, of another individual's gaze directed at the observer that leads to eye contact - is known to influence a wide range of cognitive processes and behaviors. We stress that these effects mainly reflect positive impacts on human cognition and may thus be used as relevant tools for therapeutic purposes.

OBJECTIVES

In this review, we aim (1) to provide an exhaustive review of eye contact effects while discussing the limits of the dominant models used to explain these effects, (2) to illustrate the therapeutic potential of eye contact by targeting those pathologies that show both preserved gaze processing and deficits in one or several functions that are targeted by the eye contact effects, and (3) to propose concrete ways in which eye contact could be employed as a therapeutic tool.

DISCUSSION

(1) We regroup the variety of eye contact effects into four categories, including memory effects, activation of prosocial behavior, positive appraisals of self and others and the enhancement of self-awareness. We emphasize that the models proposed to account for these effects have a poor predictive value and that further descriptions of these effects is needed. (2) We then emphasize that people with pathologies that affect memory, social behavior, and self and/or other appraisal, and self-awareness could benefit from eye contact effects. We focus on depression, autism and Alzheimer's disease to illustrate our proposal. To our knowledge, no anomaly of eye contact has been reported in depression. Patients suffering from Alzheimer disease, at the early and moderate stage, have been shown to maintain a normal amount of eye contact with their interlocutor. We take into account that autism is controversial regarding whether gaze processing is preserved or altered. In the first view, individuals are thought to elude or omit gazing at another's eyes while in the second, individuals are considered to not be able to process the gaze of others. We adopt the first stance following the view that people with autism are not interested in processing social signals such as gaze but could do so efficiently if properly motivated. For each pathology we emphasize that eye contact could be used, for example, to enhance sensitivity to bodily states, thus improving emotional decision making (in autism); to lead to more positive appraisal of the self and others (in depression); to improve memory performances (in Alzheimer disease) and, more generally, to motivate the recipient to engage in the therapeutic process. (3) Finally we propose two concrete ways to employ eye contact effects as a therapeutic tool. The first is to develop cognitive-behavioral tools to learn and/or motivate the recipient to create frequent and prolonged eye contact periods. The second is to raise awareness among caregivers of the beneficial effects of eye contact and to teach them the way to use eye contact to reach its optimum effects. Future investigations are however needed to explore the ways in which eye contact effects can be efficiently integrated in therapeutic strategies, as well as to identify the clinical populations that can benefit from such therapeutic interventions.

Serum ferritin as an early determinant of decreased iron stores in pregnant women

Serum ferritin has been shown to be an excellent determinant of iron stores. In a consecutive group of women registering at the regular prenatal clinic, we measured serum ferritin, iron, iron-binding capacity, and hemoglobin to determine their hematologic status as to anemia. It was found that serum ferritin is the most sensitive determinant of depleted iron stores, with serum iron being next in sensitivity. This assay is a rapid, economic, sensitive measure of iron stores, and results are not altered significantly by other types of anemia or oral iron therapy.