National-scale mapping of potential floral resources for honeybees and native pollinators in New Zealand.

Floral resources are important food resources for pollinators. These resources are produced in different quantities depending on land cover and plant species composition, and the quantity of production varies seasonally. As such, land use change and management of natural resources can have substantial impacts on conservation through resource provision for pollinators, and also commercial enterprises through resources for honeybee hives which require adequate forage to be successful.

Detecting Nonadditive Biotic Interactions and Assessing Their Biological Relevance among Temperate Rainforest Trees.

AbstractInteractions between and within abiotic and biotic processes generate nonadditive density-dependent effects on species performance that can vary in strength or direction across environments. If ignored, nonadditivities can lead to inaccurate predictions of species responses to environmental and compositional changes. While there are increasing empirical efforts to test the constancy of pairwise biotic interactions along environmental and compositional gradients, few assess both simultaneously.

Rooting depth and xylem vulnerability are independent woody plant traits jointly selected by aridity, seasonality, and water table depth.

Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism-resistant xylem, but little is known about how these traits have coevolved across the phylogeny of woody plants or how they jointly influence the distribution of species. We synthesized global trait and vegetation plot datasets to examine how rooting depth and xylem vulnerability across 188 woody plant species interact with aridity, precipitation seasonality, and water table depth to influence species occurrence probabilities across all biomes. Xylem resistance to embolism and rooting depth are independent woody plant traits that do not exhibit an interspecific trade-off.

Areas of global importance for conserving terrestrial biodiversity, carbon and water.

To meet the ambitious objectives of biodiversity and climate conventions, the international community requires clarity on how these objectives can be operationalized spatially and how multiple targets can be pursued concurrently. To support goal setting and the implementation of international strategies and action plans, spatial guidance is needed to identify which land areas have the potential to generate the greatest synergies between conserving biodiversity and nature's contributions to people. Here we present results from a joint optimization that minimizes the number of threatened species, maximizes carbon retention and water quality regulation, and ranks terrestrial conservation priorities globally.

The Importance of Protein Phosphorylation for Signaling and Metabolism in Response to Diel Light Cycling and Nutrient Availability in a Marine Diatom.

Diatoms are major contributors to global primary production and their populations in the modern oceans are affected by availability of iron, nitrogen, phosphate, silica, and other trace metals, vitamins, and infochemicals. However, little is known about the role of phosphorylation in diatoms and its role in regulation and signaling. We report a total of 2759 phosphorylation sites on 1502 proteins detected in .

Multiplexed Knockouts in the Model Diatom by Episomal Delivery of a Selectable Cas9.

Marine diatoms are eukaryotic microalgae that play significant ecological and biogeochemical roles in oceans. They also have significant potential as organismal platforms for exploitation to address biotechnological and industrial goals. In order to address both modes of research, sophisticated molecular and genetic tools are required.

A regional-scale assessment of using metabolic scaling theory to predict ecosystem properties.

Metabolic scaling theory (MST) is one of ecology's most high-profile general models and can be used to link size distributions and productivity in forest systems. Much of MST's foundation is based on size distributions following a power law function with a scaling exponent of -2, a property assumed to be consistent in steady-state ecosystems. We tested the theory's generality by comparing actual size distributions with those predicted using MST parameters assumed to be general.

Evolution and regulation of nitrogen flux through compartmentalized metabolic networks in a marine diatom.

Diatoms outcompete other phytoplankton for nitrate, yet little is known about the mechanisms underpinning this ability. Genomes and genome-enabled studies have shown that diatoms possess unique features of nitrogen metabolism however, the implications for nutrient utilization and growth are poorly understood. Using a combination of transcriptomics, proteomics, metabolomics, fluxomics, and flux balance analysis to examine short-term shifts in nitrogen utilization in the model pennate diatom in Phaeodactylum tricornutum, we obtained a systems-level understanding of assimilation and intracellular distribution of nitrogen.

Nitrate Reductase Knockout Uncouples Nitrate Transport from Nitrate Assimilation and Drives Repartitioning of Carbon Flux in a Model Pennate Diatom.

The ecological prominence of diatoms in the ocean environment largely results from their superior competitive ability for dissolved nitrate (NO). To investigate the cellular and genetic basis of diatom NO assimilation, we generated a knockout in the nitrate reductase gene (-KO) of the model pennate diatom In -KO cells, N-assimilation was abolished although NO transport remained intact. Unassimilated NO accumulated in -KO cells, resulting in swelling and associated changes in biochemical composition and physiology.

Inactivation of Phaeodactylum tricornutum urease gene using transcription activator-like effector nuclease-based targeted mutagenesis.

Diatoms are unicellular photosynthetic algae with promise for green production of fuels and other chemicals. Recent genome-editing techniques have greatly improved the potential of many eukaryotic genetic systems, including diatoms, to enable knowledge-based studies and bioengineering. Using a new technique, transcription activator-like effector nucleases (TALENs), the gene encoding the urease enzyme in the model diatom, Phaeodactylum tricornutum, was targeted for interruption.

High-resolution DNA melt-curve analysis for cost-effective mass screening of pairwise species interactions.

Ecological studies of pairwise interactions are constrained by the methods available for rapid species identification of the interacting organisms. The resolution of data required to characterize species interaction networks at multiple spatio-temporal scales can be intensive, and therefore laborious and costly to collect. We explore the utility of high-resolution DNA melt-curve analysis (HRM) as a rapid species identification method.

An experimental test of insect-mediated colonisation of damaged Pinus radiata trees by sapstain fungi.

Vector-pathogen dynamics play a central role in understanding tree health and forest dynamics. There is substantial evidence that bark beetles act as spore vectors for many species of fungi that cause 'sapstain' discolouration of damaged trees and timber. However, the direct quantitative link between vector-mediated spore dispersal and subsequent sapstain colonisation of wood is not fully understood.

Elimination of manganese(II,III) oxidation in Pseudomonas putida GB-1 by a double knockout of two putative multicopper oxidase genes.

Bacterial manganese(II) oxidation impacts the redox cycling of Mn, other elements, and compounds in the environment; therefore, it is important to understand the mechanisms of and enzymes responsible for Mn(II) oxidation. In several Mn(II)-oxidizing organisms, the identified Mn(II) oxidase belongs to either the multicopper oxidase (MCO) or the heme peroxidase family of proteins. However, the identity of the oxidase in Pseudomonas putida GB-1 has long remained unknown.

Evaluation of GFP tag as a screening reporter in directed evolution of a hyperthermophilic beta-glucosidase.

By applying a directed evolution methodology specific enzymatic characteristics can be enhanced, but to select mutants of interest from a large mutant bank, this approach requires high throughput screening and facile selection. To facilitate such primary screening of enhanced clones, an expression system was tested that uses a green fluorescent protein (GFP) tag from Aequorea victoria linked to the enzyme of interest. As GFP's fluorescence is readily measured, and as there is a 1:1 molar correlation between the target protein and GFP, the concept proposed was to determine whether GFP could facilitate primary screening of error-prone PCR (EPP) clones.

Genomic insights into Mn(II) oxidation by the marine alphaproteobacterium Aurantimonas sp. strain SI85-9A1.

Microbial Mn(II) oxidation has important biogeochemical consequences in marine, freshwater, and terrestrial environments, but many aspects of the physiology and biochemistry of this process remain obscure. Here, we report genomic insights into Mn(II) oxidation by the marine alphaproteobacterium Aurantimonas sp. strain SI85-9A1, isolated from the oxic/anoxic interface of a stratified fjord.

Geomicrobiology of manganese(II) oxidation.

Mn(II)-oxidizing microbes have an integral role in the biogeochemical cycling of manganese, iron, nitrogen, carbon, sulfur, and several nutrients and trace metals. There is great interest in mechanistically understanding these cycles and defining the importance of Mn(II)-oxidizing bacteria in modern and ancient geochemical environments. Linking Mn(II) oxidation to cellular function, although still enigmatic, continues to drive efforts to characterize manganese biomineralization.

Improved catalytic efficiency and active site modification of 1,4-beta-D-glucan glucohydrolase A from Thermotoga neapolitana by directed evolution.

Thermotoga neapolitana 1,4-beta-d-glucan glucohydrolase A preferentially hydrolyzes cello-oligomers, such as cellotetraose, releasing single glucose moieties from the reducing end of the cello-oligosaccharide chain. Using directed evolution techniques of error-prone PCR and mutant library screening, a variant glucan glucohydrolase has been isolated that hydrolyzes the disaccharide, cellobiose, at a 31% greater rate than its wild type (WT) predecessor. The mutant library, expressed in Escherichia coli, was screened at 85 degrees C for increased hydrolysis of cellobiose, a native substrate rather than a chromogenic analog, using a continuous, thermostable coupled enzyme assay.

Thermostable continuous coupled assay for measuring glucose using glucokinase and glucose-6-phosphate dehydrogenase from the marine hyperthermophile Thermotoga maritima.

A novel, thermostable adaptation of the coupled-enzyme assay for monitoring glucose concentrations was developed for an optimal temperature of 85 degrees C. This is the first report of a thermostable glucostat from a marine hyperthermophile. The continuous assay, using glucokinase (Glk) and glucose-6-phosphate dehydrogenase (Gpd) from Thermotoga maritima, demonstrated robust activity over a range of temperatures (75-90 degrees C) and pH values (6.