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 suitable viticulture practices.

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Agriculture is the main economic revenue in sub-Saharan African countries, playing a key role on smallholder livelihoods as household incomes and as food. Food insecurity is known to increase with the inevitable climate changes, which already affect the major farming systems, sub-Saharan Africa (SSA) being particularly susceptible, mostly due to the high dependence of rainfall for crop cycles. As such, to promote food security in a long run, new farming systems have to become more sustainable and productive at the same time. In this chapter, a global overview of major farming systems in sub-Saharan Africa is provided, and current and future production scenarios are discussed. Moreover, some of the major pillars under the sustainable land use intensification are highlighted, and the potential of the undervalued African legumes toward a sustainable crop production is debated. Finally, an outline of key opportunities to diversify cropping systems is explored along with the benefits associated to integration of local and "orphan legumes" that are considered. It is argued that the use of these "orphan legumes" and the implementation of appropriated management approaches will promote a sustainable production of more food from the same land area, relying on mutually beneficial ecological relationships and reducing environmental impacts.

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 H 2 O 2 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.

Rye (Secale cereale L.) is a cereal crop of major importance in many parts of Europe and rye breeders are presently very concerned with the 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” × “Carsten” heterotic pool in hybrid rye breeding programs. Previous studies on rye's genetic diversity revealed moreover a common genetic background on landraces (ex situ) and cultivars, regardless of breeding level or geographical origin. Thus evaluation of in situ populations is of utmost importance to unveil “on farm” diversity, which is largely undervalued. Here, we perform the first comprehensive assessment of rye's genetic diversity and population structuring using cultivars, ex situ landraces along a comprehensive sampling of in situ accessions from Portugal, through a molecular-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/ex situ collections. Such genetic distinctiveness of in situ 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, ex situ, and in situ samples in ascertaining the status of plant genetic resources (PGR).

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.

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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—SDGs—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.