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In coming years, food demand will rise sharply in line with population growth. This demand will be met largely through the expansion of agricultural land, a limited and strained resource. Therefore, it is crucial to ensure a more productive but also sustainable agricultural system. The reclamation of marginal lands underused, such as saline and drought-prone lands, or even abandoned mining areas, could be a possible solution. In this sense, phytostabilisation is considered a suitable method for their rehabilitation and reconversion to crop and livestock activities. Some pasture plants can tolerate adverse growth conditions (e.g., high concentrations of potentially hazardous elements (PHE) and EC, low pH, organic C and nutrients, and poor structure). However, limited and slow plant growth can limit the environmental rehabilitation success. The combined use of Technosols and pastures may be an effective green technology towards reclaiming these marginal areas for food production. To verify this hypothesis, this study evaluated the improvement saline soils’ properties and gossan waste through Technosols and development of a biodiverse pasture. A Technosol was constructed using a saline Fluvisol of the Tagus Estuary and another one utilizing a gossan waste from the São Domingos mine, both with a mixture of organic and inorganic amendments. Four treatments were considered: (i) Fluvisol (VF), control of salinity; (ii) Technosol-Fluvisol (TVF); (iii) gossan waste (G), control of PHE contamination; and (iv) Technosol-Gossan (TG). After two months of pasture growing, samples from each treatment were characterised for soil properties, nutrient pool, soil enzyme activities, and aggregate stability, and compared to initial conditions. Both Technosols were effective in attenuating the main disturbances of these degraded environments. In TG, the acid pH of the gossan waste was neutralised (G: 3.8 - 4.1, TG: 6.5 – 6.7). Similarly, in TVF, salinity (EC) and exchangeable Na were reduced by about 65% and 60%, respectively. Nutrient pool in both Technosols was also enhanced by overall increases in organic C, N, P, K, Ca, Fe, Zn and Cu. Likewise, microbiological activity has been stimulated by Technosols and establishment of a pasture. For example, in G dehydrogenase activity was practically null, and in TG although it was also reduced/small, it increased 15 times more. While with the pasture, it increased 6-fold. In FV there was already some dehydrogenase activity, but in TVF it was six times higher and with the pasture even more elevated, reaching values like those of a healthy grassland. The other enzymes analysed (β-glucosidase, cellulase, acid phosphatase, urease, and protease) were also stimulated. Better aggregation was also observed in Technosols, as the number of larger aggregates (> 2 mm) was higher than in controls. In TG these represented 68% compared to 34.5% in G, and in TVF 93.6% compared to 32.8% in VF. Finally, all these improvements have allowed the establishment of a good pasture. Thus, the combined use of Technosols and pastures may be an effective green technology to convert marginal lands into food production areas (grazing or foraging).

The essay discusses a continuous science teachers’ training, which occurred in a capixaba coastal plain in order to evaluate their pedagogical potentialities, in order to make the participants capable of conducing field classes for favoring the development of educational actions that allow a critical reading of the context in which they are inserted. Took part in the formation 26 students of the IFES Graduate Program, most of them teachers from public schools. It is a qualitative research activity, which used participant observation techniques and the registration of photographs and field diary for data collecting. The results showed that they have never taken part in a field class before, although this activity confers social meaning to the non formal educational settings. O trabalho discute sobre uma formação continuada de professores de ciências, a qual ocorreu em ambientes costeiros capixabas de modo a avaliar suas potencialidades pedagógicas, de modo a capacitar os participantes para a realização de aulas de campo, favorecendo o desenvolvimento de ações que possibilitam uma leitura crítica do contexto em que os alunos estão inseridos. Participaram da formação 26 alunos do mestrado Educimat do IFES, a maioria professores da rede estadual e de vários municípios do estado, além de alguns servidores do IFES. Trata-se de uma pesquisa qualitativa, a qual se utilizou das técnicas da observação participante para colher dados por meio de diário de campo e fotografias. A abordagem ocorreu na linha interdisciplinar. Os resultados apontaram que as aulas de campo não fazem parte da rotina das escolas, apesar de se constituírem em uma metodologia que pode levar os participantes a atribuírem significado social aos espaços.

In the coming years, food demand will increase sharply in line with population growth. So, production will have to increase mostly by area expansion, which could lead to biodiversity loss and an increase in greenhouse gas emissions. Furthermore, both land and water resources are limited and already under severe pressure, making it imperative to ensure a more productive but also sustainable agricultural system. A possible solution to this could be the reclamation of marginal lands, such as saline and drought-prone lands, or even abandoned mining areas. In this sense, phytostabilisation is considered a suitable method for their rehabilitation and reconversion to agricultural and livestock activities while protecting the food chain. Some pasture plants can tolerate adverse growth conditions, such as mine waste or soil conditions (e.g. high concentrations of potentially hazardous elements (PHE) and EC, low pH, organic C and nutrients, and poor structure and water holding capacity). However, low and slow plant growth can limit environmental rehabilitation success. The combined use of Technosols and pastures may be an effective green technology towards reclaiming these marginal areas for food production. To verify this hypothesis, we studied the development of a biodiverse pasture in two biogeochemically distinct Technosols. The pasture is composed of leguminous plants of the genus Trifolium sp. (T. michelianum var. paradana Savi, T. vesiculosum var. cefala Savi, T. resupinatum var. nitrofolus L., and T. squarrosum L.) and Medicago sp., and gramineous plants such as Lolium multiflorum Lam. Two Technosols have been built using a saline Fluvisol collected in the Tagus Estuary and a gossan waste from the São Domingos mine together with a mixture of organic and inorganic amendments. The microcosm assay consisted of four treatments set up in pots of 1.5 dm3 volume (four replicates): (i) Fluvisol (VF), control of salinity affection (EC: 7.9 dS/m; exchangeable sodium 25%); (ii) Technosol-Fluvisol (TVF); (iii) gossan waste (G), control of PHE contamination (g/kg As: 9.1; Pb: 29.6) ; and (iv) Technosol-Gossan (TG). One month after sowing (5 g seeds per pot), the pasture biomass generated so far was mowed to simulate livestock grazing. Pasture in FV showed no seed germination, thus no plant growth. In contrast, in G (10 cm stem length and 1.41 g DW), was observed seed germination followed by plant growth, with gramineous dominating over leguminous plants. In the Technosols, pasture growth improved extraordinarily, with plants reaching more than 15 cm stem length and higher biomass with 2.59 g DW on TVF and 3.8 g DW on TG. Moreover, the pasture was more biodiverse, with the presence of as many leguminous as gramineous. Upon the first cut, the pasture was left for another month for the plants to regrow, and then mowed for the last time. During this time, L. multiflorum has kept growing to similar sizes to the first mowing, while the leguminous have not regrown as effectively. Thus, an integrated biotechnological approach involving Technosols and pastures could be a useful green technology to convert marginal lands into food production areas (grazing or foraging).

The presence of As in soil and water can be considered a global threat that can potentially contaminate the food chain. Thus, the remediation of these resources and the decrease of As concentration is a major research goal, especially in rice that tends to accumulate As in the grain. Arsenic uptake by plant species depends on As concentration in the available fraction of the soil and speciation. Several agronomic strategies have been tested to decrease As concentration in rice grain. These include water management, nutrient management and biological approaches among others. In this context, microalgae is known to be effective in the uptake and metabolize of potentially toxic elements like As, which is a cost-effective approach compared to other agronomic strategies. However, in the view of the the current global panorama of growing respect for environmental preservation and focus on energy generation from renewable resources (including domestic and industrial waste products), the use of Microbial Fuel Cells (MFC) has been gaining increased attention. The MFCs have enormous potential as they simultaneously promote the treatment of different types of waste and generate electricity. This is possible due to the conversion of the chemical energy available in the biodegradable substrates directly into electricity, through the catalytic action of electrogenic bacteria attached to the anodic electrode. We aim to develop and establish a protocol for biodegradation of As, captured by microalgae grown in paddy rice fields, in compounds less harmful to the environment and at the same time generating electricity in a continuous process. For this purpose, a selection will be made of cathodic-algae, different electrodes and membrane materials, as well as the operating conditions of MFC. The results monitored are chemical oxygen demand, nitrogen, phosphorus, pH, and production of electricity. At the end, we will be able to evaluate the possibility of decreasing rice As uptake by microalgae that will serve as a raw material for the production of electricity. This will contribute both to help achieve the new European Green Deal policy framework linked with the UN 17 Sustainable Development Goals for 2030, by promoting a resource-efficient and competitive agri-economy while guarantying the health and well-being of citizens from environment-related risks and impacts, covering the “farm to fork” food value chain.

Land represents 29% of the earth surface, and 71% of which is habitable, but only 50% is suitable for agricultural, which makes agricultural land a valuable and finite natural resource that has been experiencing increasing pressure to respond to food, feed, industrial and population housing needs. Thus, it is necessary to change the way in which we eat and live. Mismanagement of agricultural inputs together with the improvement of human living standards and urbanization has stimulated the demand and market potential of mining and quarrying market, which has promoted the occurrence of contaminated soils with potentially hazardous elements (PTE). The recovery of marginal lands, such as salt and drought prone lands, or even abandoned mining areas could be a potential strategy to decrease the pressure over the remaining agricultural land, whilst promoting ecosystem biodiversity. The recovery of mining areas, although still controversial, it is not totally dismissible because one has to increase the knowledge of plant species that could aid in the recovery of soil contaminated PTE whilst offering alternative industrial agricultural outputs. There has been increasing efforts to create sustainable ecotechnologies to rehabilitate mining areas and create conditions for agriculture activities while protecting the food-chain. Phytostabilization is an ecotechnology towards rehabilitation, based on pedo-engineering in which Technosols are built from organic/inorganic and mine wastes (e.g. gossan), thus promoting circular economy. The effectiveness of Technosols in improving the physico-chemical characteristics of mining wastes and in the decrease of their leachates has been widely proven, especially when soil-plant systems are taken into account. Our experiment with Technosols and a multifunctional legume hyacinth bean (Lablab purpureus (L.) Sweet) showed just that. Hyacinth bean is one of the 101 orphan crops that recently have been recognized as crops for the future, due to the prospective they hold as food, feed, nutritional content and multiple agricultural outputs. Our Technosols built with organic and inorganic wastes collected from nearby industries, together with gossan material, improved the physico-chemical and biological properties of the gossan, as well as they decreased the bioavailability of PTE (As, Pb, Zn, Cu) in the soil available fraction, making it possible for hyacinth bean to develop. Our Technosols showed increased content in NPK and Corg, which was concurrent with a significant increase of soil enzymes activity, proving soil quality enhancement aiding hyacinth bean development. Moreover, hyacinth bean grown in Technosols showed an impressive shoot and root development in comparison with hyacinth bean grown in gossan. The PTE translocation (root to shoot) and accumulation (soil to shoot) coefficients values of this legume grown in Technosols indicated low PTE concentrations in the shoot, which are compatible with the potential of hyacinth bean for the rehabilitation of contaminated soils, whilst offering alternative revenues (e.g. feed). Hence, these results show the value that this orphan crop has when allied with a promising ecotechnology that contributes to promote circular economy, towards the new European Green Deal policy framework.

Several anthropic activities can increase environmental concentrations of metal(loid)s, which can be uptaken by plants. However, nature has strategies to overcome these harsh conditions and some plants thrive, withstanding stress factors associated with metal(loid)s, slowly colonizing these contaminated areas. In face of environmental changes allied with population growth and food security, it is essential to find biotechnological solutions to rehabilitate and potentiate the use of such degraded areas. Phytotechnologies are successful in situ tools for the rehabilitation of contaminated areas, but to ensure the success, one of the main challenges is the selection of the right plant species; as high concentrations of metal(loid)s affect biological processes, productivity and ultimately can result in food safety issues. In this chapter an overview of the physiological and molecular mechanisms triggered by plants to tolerate stress factors associated with metal(loid)s is provided, together with an outline of potential industrial and food crops that have been studied to rehabilitate and bring economic value to these areas, without threatening food security, human health, and ecosystem balance.

In 2005, the Economic Community of West African States (ECOWAS) adopted the Common Agricultural Policy of ECOWAS (ECOWAP), as an instrument for implementing the Comprehensive Africa Agriculture Development Program (CAADP). The main goals of ECOWAP/CAADP were set to promote agriculture development and end hunger by 2025. In this study we focused on the Cabo Verde archipelago as one of the best performing countries within ECOWAS in terms of overall sustainable development. In this paper, the evolution of the ECOWAP implementation and of the Sustainable Development Goals (SDGs) associated with agriculture in Cabo Verde, were assessed by semi-quantitative (e.g., agricultural policies, agrarian periodical literature) and quantitative (modeling regression of ECOWAP implementation and Sustainable Development Goals&mdash, SDGs&mdash, performance) analyses. Our integrated results suggest that the agriculture development strategies, the signature of ECOWAP/CAADP by the national government, and political stability might explain the progress made towards poverty reduction and the improvement of food security. The results also show that agriculture-related SDGs in Cabo Verde are higher than the mean values obtained from the remaining West African countries, well above the top 25% WA countries. Nevertheless, Cabo Verde public expenditure into agriculture under the ECOWAP was generally below the targeted 10% of the national budget, with food import required to meet internal food demands.

It is estimated that the world population reach 9.1 billion in 2050 resulting in increasing food demand and consumption, but also waste production. Moreover, to help achieve the goals set by the 2030 Agenda for Sustainable Development, it is imperative to develop sustainable strategies for the recovery marginal lands (e.g. landfills or abandoned mining areas) and create conditions for agriculture activities. Thus, there is a need to increase agricultural production and to create sustainable waste management approaches. Several landfills pose health and environmental concerns associated to non-selective deposition of wastes, which present potentially hazardous elements (PHE), and inexistence of environmental management systems. Therefore, leachates rich-in PHE can spread to adjacent areas leading to soil and water contamination. This is particularly concerning considering the growing rate of Sub-Saharan African (SSA) population that will be living in urban or peri-urban areas, and practice subsistence farming in those areas. For SSA it is estimated that by 2050 about 50% of the population will be living in towns and cities. The recovery of landfills, in addition to other environmental management measures, can involve the development of a secure plant cover that creates conditions for agriculture activities, while protecting the food-chain, but also improve environmental and landscape impacts. Plant species selected for green cover should have the ability to decrease the mobility or immobilize PHE in the rhizosphere. Furthermore, these plant species should also have low PHE translocation factors from the soil/roots to the shoots. Plants with these characteristics are not common, and it is necessary to increase our efforts to identify them. Moreover, in the scope of SSA it is important that these species should be native and known by the population. The study of African crops behaviour, such as Lablab purpureus (L.) Sweet, can be a promising option since Lablab shows the ability to accumulate PHE in the roots and low translocation factors from the soil/roots to the shoots, resulting the concentrations present in the shoots safe for animal consumption. It is important to point that the characteristics of each landfill can be totally different as well as climatic conditions where is located the landfill, thus the initial and multidisciplinary characterization of the study area is crucial. Moreover, the ecophysiological plant behaviours, namely PHE accumulation in the edible part, depends on plant species and edafoclimatic conditions, so more studies should be done in order to assess the impact in the food-chain.

To achieve the goals set by the 2030 agenda for Sustainable Development, it is imperative to create sustainable solutions to recovery marginal lands (e.g. landfills or abandoned mining areas) and create conditions for agriculture activities, but most importantly is a concern that deserves political priority. Landfills, poses health and environmental concerns due to the presence of potentially hazardous elements (PHE), among other contaminants that cannot be degraded leading to soil and water contamination, with increasing concern in the African continent. In 2018, a Report to the United Nations Framework Convention on Climate Change by the Republic of Guinea-Bissau reported that waste management is one of the major problems that the country faces. Thus, it is essential to create solutions, beyond contaminated wastes management, such as the rehabilitation of such areas. A potential rehabilitation strategy is the combination of phytostabilization with Technosols. Phytostabilization uses plants to decrease mobility or immobilize PHE in the rhizosphere. These plants should also have low PHE translocation factors from the soil/roots to the shoots. For the Technosols construction it can be used a mixture of different kinds of wastes from different origins (e.g. landfill, construction) to obtain a anthropic soil whose properties (e.g. fertility, water-holding capacity, structure) decrease PHE availability and promote plant growth, minimizing the risk to both human health and the environment. A possible strategy for the rehabilitation of contaminated areas, could be the establishment of an agroforestry system - by intercropping legumes, towards phytostabilization, using cashew as a case study due to its importance as a revenue commodity in West Africa countries (e.g.Guinea-Bissau). However, it is of utmost importance to identify the nature/quantity of PHE and wastes as well as climatic conditions for each contaminated/degraded site, before creating an agroforestry system in those areas, thus ensuring the sustainability of the phyto-geo-technology towards food security. Furthermore, potential alternative revenues obtained from the agroforestry system arise. As such, we present a potential rehabilitation agroforestry system that can in the future be useful for African countries attain the goals set for 2030 and beyond.

With the increasing population growth rate, and in order to attain the goals set by the 2030 Agenda for Sustainable Development, it is necessary to find solutions that can ensure food security and food safety. Population growth implies not only increasing food demand, but also land use for housing, which ultimately results in the need to claim more land. However, with only 30% land available in the world, it is crucial to find strategies to answer the demands for the near future. A potential strategy could be the reclaiming/recovery of marginal lands, such as salt and drought prone lands, or even abandoned mining areas, that are not suitable for farming. The latter is still a controversial approach, because of the knowledge void, as to determining pollution level, environmental and health risk assessment protocols, contaminated sites identification, all factors that can diminish the success of sustainably recover abandoned mining areas. Mining activities result in land degradation, environmental contamination and thus ecosystem disruption. Soils/wastes from mining areas are rich in potentially hazardous elements (PHE) that cannot be degraded, thus there has been recent efforts to create sustainable ecotechnologies that could rehabilitate these areas, creating conditions for agriculture activities while assuring food safety. Phytostabilization is a prospective rehabilitation strategy that uses adapted/tolerant plants towards PHE immobilization in the rhizosphere and most especially with low PHE translocation factors from soil/roots to shoots. Allying with this, one can improve soil properties (e.g. fertility, water-holding capacity, structure) to promote plant growth and PHE availability decrease, by engineering a soil (Technosol) using organic and/or inorganic amendments together with soils/wastes from the contaminated site. The combination of phytostabilization with geotechnologies can minimize the risk to both human health and the environment, while promoting solutions for waste management and circular economy. Although the combination of these strategies seems ideal, it is not without issues that have to be addressed, such as the highly important task of identifying the nature/amount of PHE, soil proprieties, climatic conditions and the PHE translocation factor of the species that could be stablished in a specific mining site for rehabilitation. In other words, for each contaminated site it is necessary to design a specific phytotechnology tailor-made for each situation. In the present study, it was evaluated the response of a highly drought tolerant legume, Lablab purpureus (L.) Sweet, which due to its multifunctionality (forage, food, ornamental and medicinal), can offer a wide range of revenue to areas that otherwise would be neglected for agricultural activities as is the case of São Domingos abandoned mine area, our study area. After Lablab growing in Technosols made with high contaminated soils (e.g. As, Pb, Cu, Zn) and organic/inorganic wastes, our findings show that Lablab accumulates PHE in the roots and the concentrations present in the shoots are safe for animal consumption, thus presenting a potential plant to rehabilitate highly contaminated sites using Technosols.

Several large-scale metabolic profiling studies have been directed to prospect crops with a major focus on yield-related traits and, ultimately, with the definition of specific markers for plant selection in breeding programs. However, some of these technologies are expensive, time-consuming and not easily feasible for a quick approach. Fatty acid profiling was described as reliable biomarkers and as a chemotaxonomic tool allowing to study not only the diversity in germplasm collections but also to discriminate their geographic origin. We have used fatty acids profiling for a preliminary assessment of Lablab purpureus (L.) Sweet (hyacinth bean) diversity and landraces discrimination. Hyacinth bean displays an enormous variability of agro-morphological traits, probably linked to the multi-purpose uses in different regions, i.e. as pulse, or as food with nutraceutical potential (Africa and Asia), forage (Africa and Australia) and ornamental (Europe and USA). Only two forage cultivars are widely marketed, cv. Rongai and cv. Highworth, with several landraces remaining to be addressed in terms of diversity. We show that fatty acids profiling was able to distinguish landraces, which display shared fatty acids with cultivars from the center of hyacinth bean diversity origin (East Africa). We propose that fatty acid profiling is a tool that may be used not only for nutritional value assessment but also as a chemodiversity tool in crop research.

Peroxiredoxins (Prx) catalyse the reduction of hydrogen peroxide (H2O2) and, in association with catalases and other peroxidases, may participate in signal transduction by regulating intercellular H2O2 concentration that in turn can control gene transcription and cell signaling. Using virus-induced-gene-silencing (VIGS), 2-Cys Peroxiredoxin (2CysPrx) family and type-II Peroxiredoxin B (PrxIIB) gene were silenced in Nicotiana benthamiana, to study the impact that the loss of function of each Prx would have in the antioxidant system under control (22 °C) and severe heat stress conditions (48 °C). The results showed that both Prxs, although in different organelles, influence the regeneration of ascorbate to a significant extent, but with different purposes. 2CysPrx affects abscisic acid (ABA) biosynthesis through ascorbate, while PrxIIB does it probably through the xanthophyll cycle. Moreover, 2CysPrx is key in H2O2 scavenging and in consequence in the regulation of ABA signaling downstream of reactive oxygen species and PrxIIB provides an important assistance for H2O2 peroxisome scavenges.

Rye(SecalecerealeL.)is a cereal crop of major importance in many parts of Europe and rye breeders are presently very concerned with th e restrict pool of rye genetic resources available.Such narrowing of rye genetic diversity results from the presence of“Petkus ”pool in most modern rye varieties as well as “Petkus”דCarsten” heterotic pool in hybrid rye breeding programs.Previous studies on rye’s genetic diversity revealed more over a common genetic background on landraces(exsitu) and cultivars,regardless of breeding level or geographical origin.Thus evaluation of in situ populations is of utmost importance to unveil “onfarm” diversity,which is largely undervalued.Here,we perform the first comprehensive assess ment of rye’s genetic diversity and population structuring using cultivars,exsitu landraces along a comprehensive sampling of insitu accessions from Portugal,through amolecular-directed analysis using SSRs markers.Rye genetic diversity and population structure analysis does not present any geographical trend but disclosed marked differences between genetic backgrounds of in situ accessions and those of cultivars/exsitu collections.Such genetic distinctiveness of insitu accessions highlights their unexplored potential as new genetic resources,which can be used to boost rye breeding strategies and the production of new varieties.Overall,our study successfully demonstrates the high prospective impact of comparing genetic diversity and structure of cultivars,exsitu,and in situ samples in ascertaining the status of plant genetic resources (PGR) info:eu-repo/semantics/publishedVersion

Micropropagated grapevine (Vitis vinifera L. var. Touriga Nacional) was transferred from heterotrophic growth conditions and PPFD of 50 μmol m−2 s−1 to ex vitro under PPFD fourfold higher, which causes photooxidative stress. We have analyzed the first 7 d of growth, focusing on the protective role of the ascorbate‐glutathione cycle and relating its activity to the functioning of photosynthetic electron transport. Immediately after transfer, reversible photoinhibition was observed. Both the photochemical efficiency of PSII and PSII excitation capture efficiency were transiently affected. Concomitantly, a transient rise in H2O2 content was observed on day 1, followed by increased activity of the ascorbate‐glutathione cycle as determined by changes to ascorbate and glutathione levels and redox states, enzyme activities, and expression of associated genes. The upregulation of ascorbate peroxidase (APX1 and APX3), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and glutathione reduct...

Plants can maintain growth and reproductive success by sensing changes in the environment and reacting through mechanisms at molecular, cellular, physiological and developmental levels. Each stress condition prompts a unique response although some overlap between the reactions to abiotic stress (drought, heat, cold, salt or high light) and to biotic stress (pathogens) does occur. A common feature in the response to all stresses is the onset of oxidative stress, through the production of reactive oxygen species (ROS). As hydrogen peroxide and superoxide are involved in stress signaling, a tight control in ROS homeostasis requires a delicate balance of systems involved in their generation and degradation. If the plant lacks the capacity to generate scavenging potential, this can ultimately lead to death. In grapevine, antioxidant homeostasis can be considered at whole plant levels and during the development cycle. The most striking example lies in berries and their derivatives, such as wine, with nutraceutical properties associated with their antioxidant capacity. Antioxidant homeostasis is tightly regulated in leaves, assuring a positive balance between photosynthesis and respiration, explaining the tolerance of many grapevine varieties to extreme environments. In this review we will focus on antioxidant metabolites, antioxidant enzymes, transcriptional regulation and cross-talk with hormones prompted by abiotic stress conditions. We will also discuss three situations that require specific homeostasis balance: biotic stress, the oxidative burst in berries at veraison and in vitro systems. The genetic plasticity of the antioxidant homeostasis response put in evidence by the different levels of tolerance to stress presented by grapevine varieties will be addressed. The gathered information is relevant to foster varietal adaptation to impending climate changes, to assist breeders in choosing the more adapted varieties and to suitable viticulture practices.

Peroxiredoxins (Prx) catalyse the reduction of hydrogen peroxide (H2O2) and, in association with catalases and other peroxidases, may participate in signal transduction by regulating intercellular H2O2 concentration that in turn can control gene transcription and cell signaling. Using virus-induced-gene-silencing (VIGS), 2-Cys Peroxiredoxin (2CysPrx) family and type-II Peroxiredoxin B (PrxIIB) gene were silenced in Nicotiana benthamiana, to study the impact that the loss of function of each Prx would have in the antioxidant system under control (22 °C) and severe heat stress conditions (48 °C). The results showed that both Prxs, although in different organelles, influence the regeneration of ascorbate to a significant extent, but with different purposes. 2CysPrx affects abscisic acid (ABA) biosynthesis through ascorbate, while PrxIIB does it probably through the xanthophyll cycle. Moreover, 2CysPrx is key in H2O2 scavenging and in consequence in the regulation of ABA signaling downstream of reactive oxygen species and PrxIIB provides an important assistance for H2O2 peroxisome scavenges.

Peroxiredoxins (Prxs) play major roles in preventing oxidative damage and their function is consistent with the presence of Prx isoforms in most, if not all, cellular compartments and their expression is dependent on environmental conditions. The aim of this study was to identify and characterize genes encoding Prxs in Vitis vinifera. Quantitative real time polymerase chain reaction (qRT PCR) was used to determine their response to irradiance, heat, and water stress. We identified seven vvprx genes, two of which were especially responsive to water stress, followed by heat stress, but no major changes were observed after high irradiance. The vvprxIIF targeted to mitochondria was the most responsive to water stress and it might be involved in drought tolerance through H2O2 signalling. The vvprxII-2, a putative PrxII, is targeted to the chloroplasts and was the most responsive to heat stress. It might be related with abscisic acid-dependent thermotolerance. Additional key words: abscisic acid, antioxidants, grapevine, heat stress, photosynthesis, qRT PCR, water stress.