Proteomic Profiling and Rhizosphere-Associated Microbial Communities Reveal Adaptive Mechanisms of Dioclea apurensis Kunth in Eastern Amazon’s Rehabilitating Minelands

Abstract

Dioclea apurensis Kunth is native to ferruginous rocky outcrops (known as canga) in the eastern Amazon. Native cangas are considered hotspots of biological diversity and have one of the largest iron ore deposits in the world. There, D. apurensis can grow in post-mining areas where molecular mechanisms and rhizospheric interactions with soil microorganisms are expected to contribute to their establishment in rehabilitating minelands (RM). In this study, we compare the root proteomic profile and rhizosphere-associated bacterial and fungal communities of D. apurensis growing in canga and RM to characterize the main mechanisms that allow the growth and establishment in post-mining areas. The results showed that proteins involved in response to oxidative stress, drought, excess of iron, and phosphorus deficiency showed higher levels in canga and, therefore, helped explain its high establishment rates in RM. Rhizospheric selectivity of microorganisms was more evident in canga. The microbial community structure was mostly different between the two habitats, denoting that despite having its preferences, D. apurensis can associate with beneficial soil microorganisms without specificity. Therefore, its good performance in RM can also be improved or attributed to its ability to cope with beneficial soil-borne microorganisms. Native plants with such adaptations must be used to enhance the rehabilitation process.

Molecular Mechanisms Underlying Mimosa acutistipula Success in Amazonian Rehabilitating Minelands

“…Canga samples were more clustered, while distances between RM plant samples indicate a more significant heterogeneity of plants grown in these ecosystems. This same pattern was observed in a study of the proteome of Dioclea apurensis from plants growing in rehabilitating minelands [ 20 ]. However, there is still no knowledge about other factors, such as the differences in the genotypic variability of these populations between RM and canga plants, which are determinants in the observed patterns.…”

“…Plants from the Fabaceae family have been described as one of the pioneer species to be used in rehabilitation programs in the eastern Amazon [ 14 , 16 , 19 , 20 ]. Among them, Mimosa acustitipula var ferrea Barneby (Fabaceae) has been classified as one of the native plants with high performance in rehabilitating minelands [ 14 , 16 , 17 ].…”

“…In recent years, proteomics has become a powerful tool for studying environmental processes, including abiotic stress tolerance, plant diseases, phytohormone metabolism, and growth promotion [ 24 , 25 , 26 ]. Recent studies have demonstrated that proteomics can be a valuable tool to explore the metabolisms of plants and microorganisms growing in severe ecosystems, including their capabilities to improve ecosystem-related services in rehabilitating minelands [ 20 , 27 ]. We hypothesized that M. acutistipula develops mechanisms of stress tolerance in the native canga, which allow its establishment in rehabilitating minelands.…”

The Root Proteomes of Mimosa acutistipula Provide Insights into the Stress Response Mechanisms in Plants Grown in Native Ecosystems and Eastern Amazon's Rehabilitating Minelands

“…Canga samples were more clustered, while distances between RM plant samples indicate more significant heterogeneity of plants grown in these ecosystems. This same pattern was observed in a study of the proteome of Dioclea apurensis from plants growing in rehabilitating minelands (Nascimento et al, 2022). However, there is still no knowledge about other factors, such as the differences in the genotypic variability of these populations between RM and canga plants, which are determinants in the observed patterns.…”

“…Plants from the Fabaceae family have been described as one of the pioneer species to be used in rehabilitation programs in the eastern Amazon [14,16,19,20]. Among them, Mimosa acustitipula var ferrea Barneby (Fabaceae) has been classified as one of the native plants with high performance in rehabilitating minelands [14,16,17].…”