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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.

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 (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.