Mangrove and salt marsh artificial warming study

This data file includes data for the growth of mangroves and salt marsh and soil elevation change for an in field warming study conducted at Merritt Island, FL

Data from: Warming accelerates mangrove expansion and surface elevation gain in a subtropical wetland

Climatic warming can change how coastal wetland plants grow, thus altering their capacity to build land and keep pace with rising seas. As freeze events decline with climate change, mangroves expand their range to higher latitudes and displace salt marsh vegetation. Warmer air temperatures will likely alter above‐ and below‐ground plant dynamics as this dramatic coastal wetland biome shift proceeds, which in turn may result in changes in ecosystem function such as sediment building. We used a large scale in situ warming experiment in a subtropical wetland to increase both marsh and mangrove ecosystem air temperatures. We assessed how 2 years of continuous warming influenced above‐ and below‐ground plant growth and surface elevation relative to sea level. We found that chronic warming doubled plant height and accelerated the expansion of mangrove into salt marsh vegetation, as indicated by a sixfold greater increase in mangrove cover in warmed plots compared to ambient temperature plots and a corresponding loss in salt marsh cover. Surface elevation gain, a measure of soil‐building capacity, increased due to warming over a 2‐year period and these changes in surface elevation were driven by increased mangrove root production in warmed plots. Synthesis. Our findings suggest that, in some coastal wetlands, warming can facilitate plant community changes from marsh to mangrove, with corresponding increases in growth that help coastal wetlands to keep pace with sea‐level rise

Adenylation-Dependent Conformation and Unfolding Pathways of the NAD(+)-Dependent DNA Ligase from the Thermophile Thermus scotoductus

In the last few years, an increased attention has been focused on NAD(+)-dependent DNA ligases. This is mostly due to their potential use as antibiotic targets, because effective inhibition of these essential enzymes would result in the death of the bacterium. However, development of an efficient drug requires that the conformational modifications involved in the catalysis of NAD(+)-dependent DNA ligases are understood. From this perspective, we have investigated the conformational changes occurring in the thermophilic Thermus scotoductus NAD(+)-DNA ligase upon adenylation, as well as the effect of cofactor binding on protein resistance to thermal and chemical (guanidine hydrochloride) denaturation. Our results indicate that cofactor binding induces conformational rearrangement within the active site and promotes a compaction of the enzyme. These data support an induced “open-closure” process upon adenylation, leading to the formation of the catalytically active enzyme that is able to bind DNA. These conformational changes are likely to be associated with the protein function, preventing the formation of nonproductive complexes between deadenylated ligases and DNA. In addition, enzyme adenylation significantly increases resistance of the protein to thermal denaturation and GdmCl-induced unfolding, establishing a thermodynamic link between ligand binding and increased conformational stability. Finally, chemical unfolding of deadenylated and adenylated enzyme is accompanied by accumulation of at least two equilibrium intermediates, the molten globule and premolten globule states. Maximal populations of these intermediates are shifted toward higher GdmCl concentrations in the case of the adenylated ligase. These data provide further insights into the properties of partially folded intermediates