A5037345006- Plant nutrient uptake and metabolism
- Soil Carbon and Nitrogen Dynamics
- Plant Water Relations and Carbon Dynamics
- Plant responses to elevated CO2
- Microbial Community Ecology and Physiology
- Atmospheric chemistry and aerosols
- Isotope Analysis in Ecology
- Plant Molecular Biology Research
- Mitochondrial Function and Pathology
- Metabolomics and Mass Spectrometry Studies
- Microbial Metabolic Engineering and Bioproduction
- Agriculture, Soil, Plant Science
- Seedling growth and survival studies
- Plant responses to water stress
- Peatlands and Wetlands Ecology
- Botany and Plant Ecology Studies
- Metabolism and Genetic Disorders
- Soil and Water Nutrient Dynamics
- Photosynthetic Processes and Mechanisms
- Microbial Metabolites in Food Biotechnology
- Marine and coastal ecosystems
- Geochemistry and Geologic Mapping
- Chromium effects and bioremediation
- Growth and nutrition in plants
- Plant Micronutrient Interactions and Effects
University of Kansas
2012-2024
University of Sheffield
2013-2017
Technical University of Munich
2005-2016
Summary The pattern of cell division, growth and separation during leaf development determines the volume airspace in a leaf. resulting balance cellular material is expected to significantly influence primary function leaf, photosynthesis, yet manner degree which division patterns affect networks photosynthesis remains largely unexplored. In this paper we investigate relationship size patterning, by promoting repressing expression cycle genes mesophyll. Using micro CT imaging quantify...
Roots and associated microbes generate acid-forming CO2 organic acids accelerate mineral weathering deep within Earth’s critical zone (CZ). At the Calhoun CZ Observatory in USA’s Southern Piedmont, we tested hypothesis that deforestation-induced root losses reduce root- microbially-mediated agents well below maximum density (to 5 m), impart land-use legacies even after ~70 y of forest regeneration. In forested plots, declined with depth to 200 cm; cultivated roots approached zero at depths...
The substrate supply system for respiration of the shoot and root perennial ryegrass (Lolium perenne) was characterized in terms component pools pools' functional properties: size, half-life, contribution to shoot. These investigations were performed with growing constant conditions continuous light. Plants labeled 13CO2/12CO2 periods ranging from 1 600 h, followed by measurements rates 13C/12C ratios CO2 respired shoots roots dark. Label appearance delayed approximately h relative shoots;...
This work assessed the central carbohydrate metabolism of actively photosynthesizing leaf blades a C3 grass (Lolium perenne L.). The study used dynamic 13C labelling plants growing in continuous light with contrasting supplies nitrogen ('low N' and 'high N') mathematical analysis tracer data four-pool compartmental model to estimate rates of: (i) sucrose synthesis from current assimilation; (ii) export/use; (iii) hydrolysis (to glucose fructose) resynthesis; (iv) fructan resynthesis...
The effect of nitrogen (N) stress on the pool system supplying currently assimilated and (re)mobilized N for leaf growth a grass was explored by dynamic ¹⁵N labeling, assessment total labeled import into zones, compartmental analysis label data. Perennial ryegrass (Lolium perenne) plants, grown with low or high levels fertilization, were ¹⁵NO₃⁻/¹⁴NO₃⁻ from 2 h to more than 20 d. In both treatments, tracer time course in imported zones fitted two-pool model (r² > 0.99). This consisted...
The causal relationship between cell division and growth in plants is complex. Although altered expression of cell-cycle genes frequently leads to organ growth, there are many examples where manipulation the machinery a limited outcome at level form, despite changes constituent size. One possibility, which has been under-explored, that patterns resulting from gene alter physiology organ, this an effect on growth. We performed series experiments retinoblastoma-related protein (RBR), well...
Plant carbon-use-efficiency (CUE), a key parameter in carbon cycle and plant growth models, quantifies the fraction of fixed that is converted into net primary production rather than respired. CUE has not been directly measured, partly because difficulty measuring respiration light. Here, we explore if affected by atmospheric CO2 . Sunflower stands were grown at low (200 μmol mol-1 ) or high (1000 controlled environment mesocosms. was measured dynamic stand-scale 13 C labelling partitioning...
Microbial transformations of organic carbon (OC) generate a large flux CO2 into the atmosphere and influence C balance terrestrial aquatic ecosystems. Yet, inherent heterogeneity in natural environments precludes direct quantification multiple microbial fluxes that underlie production. Here we used continuous flow bioreactor coupled with stable isotope analyzer to determine effects temperature availability (cellobiose concentration) on 13C discrimination population growing at steady-state...
Abstract. Understanding how carbon dioxide (CO2) flux from ecosystems feeds back to climate warming depends in part on our ability quantify the efficiency with which microorganisms convert organic (C) into either biomass or CO2. Quantifying ecosystem-level respiratory CO2 losses often also requires assumptions about stable C isotope fractionations associated microbial transformation of substrates. However, diversity substrates' δ13C and challenges measuring use (CUE) their natural...
• The mechanism controlling the use of stored carbon in respiration is poorly understood. Here, we explore if reliance on stores as respiratory substrate depends day length. Lolium perenne (perennial ryegrass) was grown continuous light (275 μmol photons m−2 s−1) or a 16 : 8 h night regime (425 s−1 during photoperiod), with same daily photosynthetic photon flux density (PPFD). Plants stands were labelled 13CO2 12CO2 for various time intervals. rates and isotopic signatures shoot-...
Leaves are derived from heterotrophic meristem tissue that, at some point, must make the transition to autotrophy via initiation of photosynthesis. However, timing and spatial coordination molecular cellular processes underpinning this switch poorly characterized. Here, we report on identification a specific stage in rice (Oryza sativa) leaf development (P3/P4 transition) when photosynthetic competence is first established. Using combined physiological approach, show that elements stomatal...
Plant respiration draws on substrate pools of different functional/biochemical identity. Little is known about the effect nitrogen deficiency those pools' sizes, half-lives and relative contribution to respiration, consequently, carbon residence time in respiratory metabolism. Here we studied how fertilization affects supply system shoots roots Lolium perenne, a perennial grass. Plants grown at two levels continuous light were labelled with 13CO2/12CO2 for intervals ranging from 1 h month....
• Here, we analysed the transition from heterotrophic to autotrophic growth of epigeal species sunflower (Helianthus annuus), and how is affected by CO2. Growth analysis steady-state 13CO2/12CO2 15NO3−/14NO3− labelling were used quantify reserve- current assimilation-derived carbon (C) nitrogen (N) allocation shoots roots in presence 200 1000 µmol CO2 mol−1 air. was not influenced until cotyledons unfolded. Then, C accumulation at elevated increased a rate 2–2.5 times higher than subambient...
Abstract. Understanding how carbon dioxide (CO2) flux from soils feeds back to climate warming depends in part on our ability quantify the efficiency with which microorganisms convert soil organic (C) into either biomass or CO2. Quantifying ecosystem-level respiratory CO2 losses often also requires assumptions about stable C isotope fractionations associated microbial transformation of substrates. However, diversity substrates' δ13C and challenges measuring use (CUE) fundamentally limit...
Replacing long-lived, rarely disturbed vegetation with short-lived, frequently is a widespread phenomenon in the Anthropocene that can influence ecosystem functioning and soil development by reducing abundance of deep roots. We explore how sources fate CO2 vary organic substrate source, respiring biota (i.e., roots microbes), season, depth. quantified multiple isotopic signatures (δ13C, Δ14C, δ18O) as well concentrations δ18O free O2 upper 5 m at sites where root abundances C have been...