Isabelle Laforest-Lapointe

Université de Sherbrooke | UdeS · Department of Biology

The interactions between sugar maple (Acer saccharum, Marshall) and its microbial communities are important for tree fitness, growth, and establishment. Despite recent progress in our understanding of the rhizosphere and phyllosphere microbial communities of sugar maple, many outstanding knowledge gaps remain. This review delves into the relationsh...

Revegetating waste rocks is essential for re-establishing a functional ecosystem, but it poses significant challenges. Nutrient-poor soil and high exposure to elements cause high seedling mortality in the first year. Survival can be increased by amending soil with organic matter before plantation to improve water retention and nutrient availability...

Moss-microbe interactions contribute to ecosystem processes in boreal forests. Yet, how host-specific characteristics and the environment drive the composition and metabolic potential of moss microbiomes is still poorly understood. In this study, we use shotgun metagenomics to identify the taxonomy and metabolic potential of the bacteria of four mo...

Chloroplasts are essential centers of signal integration and transduction in plants. They are involved in the biosynthesis of primary and specialized metabolites, including salicylic acid (SA), a key defense phytohormone synthesized via the conserved chorismate biosynthetic pathway. However, the identity of the signal(s) that ultimately triggers SA...

Bacteria are involved in numerous interactions during infection and among host-associated microbial populations. Salmonella enterica serovar Typhimurium is a foodborne pathogen of great importance as well as a model organism to study interactions within a microbial community. In this study, we found that S. Typhimurium becomes tolerant to azithromy...

Foliar fungi on urban trees are important for tree health, biodiversity and ecosystem functioning. Yet, we lack insights into how urbanization influences foliar fungal communities. We created detailed maps of Stockholm region’s climate and air quality and characterized foliar fungi from mature oaks ( Quercus robur ) across climatic, air quality and...

Myotonic dystrophy type 1 (DM1) is a rare autosomal dominant genetic disorder. Although DM1 is primarily characterized by progressive muscular weakness, it exhibits many multisystemic manifestations, such as cognitive deficits, cardiac conduction abnormalities, and cataracts, as well as endocrine and reproductive issues. Additionally, the gastroint...

The phyllosphere, a reservoir of diverse microbial life associated with plant health, harbors microbial communities that are subject to various complex ecological processes acting at multiple scales. In this study, we investigated the determinants of the spatiotemporal variation in bacterial and fungal communities within the apple tree phyllosphere...

Root-associated microbes can alleviate plant abiotic stresses, thus potentially supporting adaptation to a changing climate or to novel environments during range expansion. While climate change is extending plant species fundamental niches northward, the distribution and colonization of mutualists (e.g., arbuscular mycorrhizal fungi) and pathogens...

Background The gut microbiome undergoes primary ecological succession over the course of early life before achieving ecosystem stability around 3 years of age. These maturational patterns have been well-characterized for bacteria, but limited descriptions exist for other microbiota members, such as fungi. Further, our current understanding of the p...

Bacteria are involved in numerous interactions during infection and among host-associated microbial populations. Salmonella enterica serovar Typhimurium is a foodborne pathogen of great importance as well as a model organism to study interactions within a microbial community. In this study, we found that S . Typhimurium becomes tolerant to azithrom...

Moss microbial communities play important roles for ecosystem processes in boreal forests. Host moss identity and leaf litter presence can affect microbial community structures of mosses. However, the extent to which host-specific characteristics and land use type affect taxonomic and functional profiles of microbial communities of boreal mosses is...

Many plant pathogens induce water-soaked lesions in infected tissues. In the case of Pseudomonas syringae (Pst), water-soaking effectors stimulate abscisic acid (ABA) production and signaling, resulting in stomatal closure. This reduces transpiration, increases water accumulation, and induces an apoplastic microenvironment favorable for bacterial g...

Unlike the bacterial microbiome, the role of early-life gut fungi in host metabolism and childhood obesity development remains poorly characterized. To address this, we investigate the relationship between the gut mycobiome of 100 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study and body mass index Z scores (BM...

Soil microbes play an undeniable role in sustainable agriculture, plant health, and soil management. A deeper understanding of soil microbial composition and function has been gained through next-generation sequencing. While soil metagenomics has provided valuable information about microbial diversity, issues stemming from RNA extraction, low RNA a...

Soil microbes play an undeniable role in sustainable agriculture, plant health, and soil management. A deeper understanding of soil microbial composition and function has been gained through next-generation sequencing. While soil metagenomics has provided valuable information about microbial diversity, issues stemming from RNA extraction, low RNA a...

Upon establishment of an infection, many plant pathogens induce an aqueous microenvironment in the extracellular space of their host, resulting in water-soaked lesions. In the case of Pseudomonas syringae (Pst), this is accomplished through the activity of water-soaking effectors that stimulate abscisic acid (ABA) production and signaling, which re...

It is undeniable that soil microbiomes contribute to sustainable agriculture, plant health, and soil management. Next-generation sequencing has made it possible to study soil microbiomes with metagenomics and metatranscriptomics. However, several issues have slowed the progress of soil metatranscriptomics. For example, obtaining a product with high...

Climate change is prompting plants to migrate and establish novel interactions in new habitats. Because of the pivotal roles that microbes have on plant health and function, it is important to understand the ecological consequences of these shifts in host–microbe interactions with range expansion. Here we examine how the diversity of plant‐associat...

Feather mosses are abundant cryptogams of the boreal forest floor and shelter a broad diversity of bacteria who have important ecological functions (e.g., decomposition, nutrient cycling). In particular, nitrogen (N2-) fixation performed by feather moss-associated diazotrophs constitutes an important entry of nitrogen in the boreal forest ecosystem...

Background Colorectal cancer (CRC) is a disease easy to cure but quite difficult to detect. Because of that, the mortality rate of CRC is among the highest in the world. The current way to clinically detect CRC is by mean of immunochromatographic fecal occult blood test (iFOBT). If the test is positive, the patient undergoes a colonoscopy to confir...

In soil, despite the great diversity and abundance of viruses and virus-like particles, most microbiome studies have focused on bacterial, fungal, and nematode communities. Thus, the impacts of soil viruses on microbial communities and viral diversity in agricultural soils are understudied. Because viruses infect all living microorganisms in the so...

Global change is a defining feature of the Anthropocene, the current human-dominated epoch, and poses imminent threats to ecosystem dynamics and services such as plant productivity, biodiversity, and environmental regulation. In this era, terrestrial ecosystems are experiencing perturbations linked to direct habitat modifications as well as indirec...

The impact of intestinal eukaryotes on the prokaryotic microbiome composition of asymptomatic carriers has not been extensively explored, especially in infants and mothers with multiple parasitic infections. In this work, we studied the relationship between protist and helminth parasite colonization and the intestinal microbiota structure in an asy...

Colorectal cancer (CRC), the third most common cancer in the world, has been recently rising in emerging countries due to environmental and lifestyle factors. Many of these factors are brought up by industrialization, which includes lack of physical activity, poor diet, circadian rhythm disruption, and increase in alcohol consumption. They can incr...

Pulsed antibiotic treatment (PAT) early in life increases risk of obesity. Prebiotics can reduce fat mass and improve metabolic health. We examined if co-administering prebiotic with PAT reduces obesity risk in rat pups weaned onto a high fat/sucrose diet. Pups were randomized to (1) control [CTR], (2) antibiotic [ABT] (azithromycin), (3) prebiotic...

Artificial sweetener consumption by pregnant women has been associated with an increased risk of infant obesity, but the underlying mechanisms are unknown. We aimed to determine if maternal consumption of artificially sweetened beverages (ASB) during pregnancy is associated with modifications of infant gut bacterial community composition and functi...

Background Inhaled tobramycin powder/solution (TIP/S) use has resulted in improved clinical outcomes in patients with cystic fibrosis (CF) with chronic Pseudomonas aeruginosa . However, TIP/S effect on the CF sputum microbiome has not been explored. We hypothesised that TIP/S has additional ‘off-target’ effects beyond merely P. aeruginosa and that...

Le Québec est mieux équipé que d’autres espaces nationaux parce que ses citoyens ont en partage des repères sociétaux clés ce qui permet à la communauté de construire sur cette cohésion et se projeter en faisant le point sur « un avant » et en imaginant « un après » à la crise sanitaire. Cela se fera en tablant sur quatre processus : le retour de l...

Ces textes représentent un effort collectif d'universitaires et de chercheurs du milieu collégial, principalement au Québec, mais aussi d'autres établissements d'enseignement supérieur au Canada, à penser toutes les répercussions et les conséquences de la pandémie de la COVID-19 sur nos vies, et ce dans toutes les constellations de la vie scientifi...

Scope : Antibiotics in early life disrupt microbiota and increase obesity risk, whereas dietary agents such as prebiotics may reduce obesity risk. We examined how antibiotics administered with/without prebiotic oligofructose, alter metabolic and microbial outcomes in pregnant rats and their offspring. Methods and results : Pregnant rats were random...

The gut microbiome consists of a multi-kingdom microbial community. Whilst the role of bacteria as causal contributors governing host physiological development is well established, the role of fungi remains to be determined. Here, we use germ-free mice colonized with defined species of bacteria, fungi, or both to differentiate the causal role of fu...

Artificial sweetener consumption by pregnant women has been associated with an increased risk of infant obesity, but the underlying mechanisms are unknown. We aimed to determine if maternal consumption of artificially sweetened beverages (ASB) during pregnancy is associated with modifications of infant gut bacterial community composition during the...

Gut microbiomes make major contributions to the physiological and immunological development of the host, but the relative importance of their bacterial and fungal components, and how they interact, remain largely unknown. We applied carefully controlled experiments in gnotobiotic mice colonized with defined communities of bacteria, fungi, or both t...

Around 3.5 billion people are colonized by intestinal parasites worldwide. Intestinal parasitic eukaryotes interact not only with the host, but also with the intestinal microbiota. In this work, we studied the relationship between the presence of multiple enteric parasites and the community structure of the bacterial and eukaryote intestinal microb...

Background: To improve clinical outcomes, cystic fibrosis (CF) patients with chronic Pseudomonas aeruginosa infections are prescribed inhaled anti-pseudomonal antibiotics. Although, a diverse microbial community exists within CF airways, little is known about how the CF microbiota influences patient outcomes. We hypothesized that organisms within...

Background Bacteria, archaea, viruses and fungi live in various plant compartments including leaves and roots. These plant-associated microbial communities have many effects on host fitness and function. Global climate change is impacting plant species distributions, a phenomenon that will affect plant-microbe interactions both directly and indirec...

Supplementary Material Figures S1–S2 and Tables S1–S3

Blastocystis is the most prevalent protist of the human intestine, colonizing approximately 20% of the North American population and up to 100% in some nonindustrialized settings. Blastocystis is associated with gastrointestinal and systemic disease but can also be an asymptomatic colonizer in large populations. While recent findings in humans have...

Freshwater bacterioplankton communities are influenced by the inputs of material and bacteria from the surrounding landscape, yet few studies have investigated how different terrestrial inputs affect bacterioplankton. We examined whether the addition of soils collected under various tree species combinations differentially influences lake bacterial...

Human-associated microbial communities include prokaryotic and eukaryotic organisms across high-level clades of the tree of life. While advances in high-throughput sequencing technology allow for the study of diverse lineages, the vast majority of studies are limited to bacteria, and very little is known on how eukaryote microbes fit in the overall...

Tree leaf-associated microbiota have been studied in natural ecosystems but less so in urban settings, where anthropogenic pressures on trees could impact microbial communities and modify their interaction with their hosts. Additionally, trees act as vectors spreading bacterial cells in the air in urban environments due to the density of microbial...

Alterations in gut microbial colonization during early life have been reported in infants that later developed asthma, allergies, type 1 diabetes, as well as in inflammatory bowel disease patients, previous to disease flares. Mechanistic studies in animal models have established that microbial alterations influence disease pathogenesis via changes...

Research on biodiversity and ecosystem functioning has demonstrated links between plant diversity and ecosystem functions such as productivity. At other trophic levels, the plant microbiome has been shown to influence host plant fitness and function, and host-associated microbes have been proposed to influence ecosystem function through their role...

Tree plantations are commonly used to restore abandoned agricultural fields with varying degrees of success. Agricultural soils differ from forest soils in nutrient availability and microbial communities. The objective of this study was to test the effect of adding small amounts of forest soil on the survival, growth and rates of mycorrhizal fungal...

Background The diversity and composition of the microbial community of tree leaves (the phyllosphere) varies among trees and host species and along spatial, temporal, and environmental gradients. Phyllosphere community variation within the canopy of an individual tree exists but the importance of this variation relative to among-tree and among-spec...

Background: The increasing awareness of the role of phyllosphere microbial communities in plant health calls for a greater understanding of their structure and dynamics in natural ecosystems. Since most knowledge of tree phyllosphere bacterial communities has been gathered in tropical forests, our goal was to characterize the community structure a...

The temperate forests of Mexico are important economically for many small communities as they provide numerous essential ecosystem services. They also contain the highest biodiversity of oak and pine species in the world. Yet they have not been discussed and investigated as much as other temperate forests. This paper presents these unique temperate...

Although intraspecific trait variability is an important component of species ecological plasticity and niche breadth, its implications for community and functional ecology have not been thoroughly explored. We characterized the intraspecific functional trait variability of Scots pine (Pinus sylvestris) in Catalonia (NE Spain) in order to (1) compa...