Biotechnology and bioprospecting of Prosopis alpataco from Patagonia, Argentina

Abstract

The genus Prosopis (Fabaceae) has been widely studied around the world for its ethnobiological and ecological value. In drylands, there are several reasons why Prosopis spp. can beconsidered as a valid option to contribute to regional sustainable development due to their resistance to water, thermal and saline stress conditions, and the nutritional properties of itspods (Cattaneo et al., 2016; Moreno, Torres, & Campos, 2018; Villagra & Cavagnaro, 2006). Prosopis species have been used since ancient times as native food crops that can be grownin areas considered unsuitable for agriculture because of different environmental stress situations (Castro Navarro, 2017). In addition, these species improve soil properties, facilitate the growth and development of other plant species (Felker, 1979) and increase the biodiversity of ecosystems. For this reason, they are considered multipurpose species and have been proposed as an alternative to ecological restoration or rehabilitation, particularly in arid environments, such as the Monte phytogeographic province, Argentina, which is affected by moderate to severe desertification (Mazzonia & Vazquez, 2009). There are 40 species of Prosopis in the Americas, 30 of which are found in Argentina, being this the country with the largest number of species, where 13 of them are endemic (Burkart, 1976; Steibel & Troiani, 2020). In the Patagonian arid environments, there are eight species, which can be considered the southernmost Prosopis species in the world. There is consensus among scholar academics that the main center of diversity and polymorphism of this genus is the Argentine?Paraguayan?Chilean region (Mcrostie et al., 2017) and that it may have subsequently expanded into xeric territories, as could have been the case of Prosopis alpataco. This species is distributed from the central to the southern part of the Monte phytogeographic province and it is considered a key species of this region as a result of their morphological and physiological adaptations. It reaches its ecological optimum in heavy clayish, saline, and sporadically flooded soils of arid areas with a dry and hot climate, summer rainfall, and averagetemperatures of 15?17 °C (Villagra, 1998; Villagra & Cavagnaro, 2005). P. alpataco developed morphological and physiological adaptations that allowed it to colonize xeric environments, including the appearance of shrub forms, seed dormancy, reduction of leaf area, changes in root architecture and wood types (Villagra & Roig-Juñent, 1997). For example, its seeds have a physical dormancy that allows the temporal and spatial regulation of germination in unpredictable environments, which gives them an adaptive advantage in xeric conditions (Villagra, 1995; Villagra & Cavagnaro, 2006). In this context, germination will not take place when environmental conditions are not favorable for seedling development. Currently, P. alpataco is propagated by seeds, so there is great interest in developing techniques that can provide a more efficient alternative to traditional propagation methods. Thus, sexual reproduction is complemented by other strategies, like micropropagation, to produce seedlings of forest species from arid areas in order to restore degraded ecosystems. In recent years, some attempts have been made to micro propagate this species, and an efficient plant tissue culture protocol has been reported for alpatacos distributed further south (Boeri & Sharry, 2018). On the other hand, the expansion and adaptation to xeric environments are likely to include modifications in the metabolic pathways of the plant with the production of secondary metabolites. These phytocomposites do not play a direct role in the vital processes of the plant but are related to its survival mechanisms in response to different environmental conditions. In this context, under abiotic stress conditions, the biosynthesis of secondary metabolites generally increases in plants (Sharma et al., 2019). Bioprospecting techniques allow evaluating and quantifying the compounds present in species adapted to xeric environments, such as Prosopis alpataco. Hence, the study of native genus species could provide the knowledge needed to find new bioproducts and characterize potential sources of food and medicine. Consequently, these characterizations give an additional value to the native flora, which has a positive impact on people?s lives (Boeri et al., 2018). In this chapter, we present a detailed description of the different sexual and vegetative propagation strategies of Prosopis alpataco. Furthermore, we update information about differents bioprospecting aspects of this species, based on previous research.