Microfluidics to Follow Spatiotemporal Dynamics at the Nucleo-Cytoplasmic Interface During Plant Root Growth.

Nuclear dynamics refers to global/local changes in the molecular and spatial organization of genomic DNA that can occur during development or in response to environmental stress signals and eventually impact genomic functions. In plants, nuclear dynamics relies notably on the connection of the nucleus with the cytoskeleton during development. It orchestrates genomic functions in response to developmental and environmental cues.

Composition and metabolism of microbial communities in soil pores.

Delineation of microbial habitats within the soil matrix and characterization of their environments and metabolic processes are crucial to understand soil functioning, yet their experimental identification remains persistently limited. We combined single- and triple-energy X-ray computed microtomography with pore specific allocation of C labeled glucose and subsequent stable isotope probing to demonstrate how long-term disparities in vegetation history modify spatial distribution patterns of soil pore and particulate organic matter drivers of microbial habitats, and to probe bacterial communities populating such habitats. Here we show striking differences between large (30-150 µm Ø) and small (4-10 µm Ø) soil pores in (i) microbial diversity, composition, and life-strategies, (ii) responses to added substrate, (iii) metabolic pathways, and (iv) the processing and fate of labile C.

The soil pore structure encountered by roots affects plant-derived carbon inputs and fate.

Plant roots are the main supplier of carbon (C) to the soil, the largest terrestrial C reservoir. Soil pore structure drives root growth, yet how it affects belowground C inputs remains a critical knowledge gap. By combining X-ray computed tomography with C plant labelling, we identified root-soil contact as a previously unrecognised influence on belowground plant C allocations and on the fate of plant-derived C in the soil.

Partitioning and subsampling statistics in compartment-based quantification methods.

The precision of compartment-based quantification methods is subject to multiple effects, of which partitioning and subsampling play a major role. Partitioning is the process of aliquoting the sample liquid and consequently the contained target molecules, whereas subsampling denotes the fact that usually only a portion of a sample is analyzed. In this work, we present a detailed statistical description comprising the effects of partitioning and subsampling on the relative uncertainty of the test result.

Distribution of Mn Oxidation States in Grassland Soils and Their Relationships with Soil Pores.

Manganese (Mn) is known to be an active contributor to processing and cycling of soil organic carbon (C), yet the exact mechanisms behind its interactions with C are poorly understood. Plant diversity in terrestrial ecosystems drives feedback links between plant C inputs and soil pores, where the latter, in turn, impact the redox environment and Mn. This study examined associations between soil pores (>36 μm Ø) and Mn within intact soils from two grassland ecosystems, after their >6-year implementation in a replicated field experiment.