Biology subjects

Adams, M. A.

Publications and source records attributed to Adams, M. A..

3 recordsLinked to original sources

bioRxiv2021

AusTraits: a curated plant trait database for the Australian flora

We introduce the AusTraits database - a compilation of measurements of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 375 traits across 29230 taxa from field campaigns, published literature, taxonomic monographs, and individual taxa descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological parameters (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual-, species- and genus-level observations coupled to, where available, contextual information on site properties. This data descriptor provides information on version 2.1.0 of AusTraits which contains data for 937243 trait-by-taxa combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data to increase our collective understanding of the Australian flora.

ecology↗

bioRxiv2020

Disproportionate CH4 sink strength from an endemic, sub-alpine Australian soil microbial community

Soil-to-atmosphere methane (CH4) fluxes are dependent on opposing microbial processes of production and consumption. Here we use a soil-vegetation gradient in an Australian sub-alpine ecosystem to examine links between composition of soil microbial communities, and the fluxes of greenhouse gases they regulate. For each soil-vegetation type (forest, grassland, and bog), we measured carbon dioxide (CO2) and CH4 fluxes and their production/consumption at 5-cm intervals to a depth of 30 cm. All soils were sources of CO2, ranging from 49-93 mg CO2 m-2 h-1. Forest soils were strong net sinks for CH4 at rates up to -413 {micro}g CH4 m-2 h-1. Grassland soils varied with some soils acting as sources and some as sinks, but overall averaged -97 {micro}g CH4 m-2 h-1. Bog soils were net sources of CH4 (+340 {micro}g CH4 m-2 h-1). Methanotrophs were dominated by USC in forest and grassland soils, and Candidatus Methylomirabilis sp. in the bog soils. Methylocystis were also detected at relatively low abundance. The potential disproportionately large contribution of these ecosystems to global CH4 oxidation, and poorly understood microbial community regulating it, highlight our dependence on soil ecosystem services in remote locations can be driven by a unique population of soil microbes. Originality-Significance Statement(Identify the key aspects of originality and significance that place the work within the top 10% of current research in environmental microbiology) Novel methanotrophic bacteria have been discovered in recent years, but few studies have examined the total known diversity of methanotrophs together with the net flux of CH4 from soils. We used an ecosystem with a vegetation-soil gradient in the sub-alpine regions of Australia (with extremely strong consumption of atmospheric CH4) to examine microbial and abiotic drivers of CH4 fluxes across this gradient. Recently characterized methanotrophs, either USC in forest and grassland soils, or oxygenic Candidatus Methylomirabilis sp. in the bog soil were dominant. Methanotrophs belonging to the families Methylococcaceae and Methylocystaceae represented only a small minority of the methanotrophs in this ecosystem.

microbiology↗

bioRxiv2020

Vascular calcification has a role in acute non-renal phosphate clearance

RationaleNon-renal extravasation of phosphate from the circulation and transient accumulation into tissues and extracellular fluid is a regulated process of acute phosphate homeostasis that is not well understood. Following oral consumption of phosphate, circulating levels normalize long before urinary excretion has been completed. This process is especially relevant in the setting of chronic kidney disease (CKD), where phosphate exposure is prolonged due to inefficient kidney excretion. Furthermore, CKD-associated dysregulation of mineral metabolism exacerbates pathological accumulation of phosphate causing vascular calcification (VC). ObjectiveDetermine whether the systemic response to acute phosphate challenges is altered by the development and progression of VC. Methods/ResultsAcute circulating and tissue deposition of an acute phosphate challenge was assessed in two rat models of VC using radio-labelled phosphate tracer. In an adenine-induced model of CKD with VC, animals with VC had a blunted elevation of circulating 33PO4 following oral phosphate administration and the discordant deposition could be traced to the calcifying vasculature. In a non-CKD model of VC, VC was induced with 0.5ug/kg calcitriol and then withdrawn. The radio-labelled phosphate challenge was given to assess for vascular preference for phosphate uptake with and without the presence of an active calcification stimulus. The new transport to the calcifying vasculature correlates to the pre-existing burden of calcification, and can be substantially attenuated by removing the stimulus for calcification. The accrual is stimulated by a phosphate challenge, and not present in the same degree during passive disposition of circulating phosphate. ConclusionsOur data indicate that calcifying arteries alter the systemic disposition of a phosphate challenge and acutely deposit substantial phosphate. This study supports the importance of diet as it relates to acute fluctuations of circulating phosphate and the importance of bioavailability and meal-to-meal management in CKD patients as a mediator of cardiovascular risk.

pathology↗