Biology subjects

Jassey, V. E.

Publications and source records attributed to Jassey, V. E..

3 recordsLinked to original sources

bioRxiv2025

Diversity, abundance, and biogeography of CO2 fixing microorganisms in peatlands

Microbial communities play a crucial role in the carbon (C) dynamic of peatlands-- a major terrestrial C reservoir. While heterotrophic microorganisms attracted much attention over the past decades due to their role in peatland greenhouse gases emissions, CO2 fixing microorganisms (CFMs) remained particularly overlooked. Here, by leveraging metabarcoding and digital droplet PCR (ddPCR), we provide a comprehensive survey of CFM communities, including oxygenic phototrophs, chemoautotrophs and aerobic anoxygenic phototrophic bacteria (AAnPBs), in different peatland types. We demonstrate that CFMs are very abundant and diverse in peatlands, with on average 1021 CFMs contributing up to 40% of the total bacterial abundance. In particular, we show that oxygenic phototrophs (mostly Cyanophyceae and Palmophylloceae) are the most abundant CFMs, closely followed by chemoautotrophs (Proteobacteria) and AAnPBs (Vulcanimicrobiia). Using a joint-species distribution model, we further find that CFMs aggregate into six major clusters with different niche size. These clusters constitute the core and specific CFM microbiome. The core microbiome, which the occurrence is strongly influenced by temperature and nutrients, directly modulate the diversity and abundance of CFMs. Our findings highlight the importance of CFM diversity and abundance in peatlands, further reveal their complex structuration in link with environmental conditions and suggest that changes in environmental conditions could shift CFMs communities. These results are the foundation to better understand the role of CFMs for the peatland C cycle inputs.

microbiology↗

bioRxiv2023

Leaf metabolic traits reveal hidden dimensions of plant form and function

The plant metabolome encompasses the biochemical mechanisms through which evolutionary and ecological processes shape plant form and function1,2. However, while the metabolome should thus be an important component of plant life-history variation3, we know little about how it varies across the plant kingdom. Here, we use the plant functional trait concept4 - a powerful framework for describing plant form and function5-7 - to interpret leaf metabolome variation among 457 tropical and 339 temperate plant species. Distilling metabolite chemistry into five discriminant metabolic functional traits reveals that plants vary along two major axes of leaf metabolic specialization - a leaf chemical defense spectrum and an expression of leaf longevity. These axes are qualitatively consistent for tropical and temperate species, with many trait combinations being viable. However, axes of leaf metabolic specialization vary orthogonally to life-history strategies described by widely used functional traits5-7, while being at least equally important to them. Our findings question classical trait6 and plant defense8 theory that predicts relationships between the leaf chemical phenotype, plant productivity, and pace of life. Moreover, we show that metabolic functional traits describe unique dimensions of plant life-history variation that are complementary to, and independent from, those captured by existing plant functional traits.

ecology↗

bioRxiv2020

Rewiring of peatland plant-microbe networks outpaces species turnover

Enviro-climatological changes are thought to be causing alterations in ecosystem processes through shifts in plant and microbial communities; however, how links between plant and microbial communities change with enviro-climatological change is likely to be less straightforward but may be fundamental for many ecological processes. To address this, we assessed the composition of the plant community and the prokaryotic community -using amplicon-based sequencing- of three European peatlands that were distinct in enviro-climatological conditions. Bipartite networks were used to construct site-specific plant-prokaryote co-occurrence networks. Our data show that between sites, plant and prokaryotic communities differ and that turnover in interactions between the communities was complex. Essentially, turnover in plant-microbial interactions is much faster than turnover in the respective communities. Our findings suggest that network rewiring does largely result from novel associations between species that are common and shared across the networks. Turnover in network composition is largely driven by novel interactions between a core community of plants and microorganisms. Taken together our results indicate that plant-microbe associations are context dependent, and that changes in enviro-climatological conditions will likely lead to network rewiring. Integrating turnover in plant-microbe interactions into studies that assess the impact of enviro-climatological change on peatland ecosystems is essential to understand ecosystem dynamics and must be combined with studies on the impact of these changes on ecosystem processes.

ecology↗