Biology subjects

Opik, M.

Publications and source records attributed to Opik, M..

4 recordsLinked to original sources

bioRxiv2024

AusAMF: database of arbuscular mycorrhizal fungal communities in Australia

MotivationArbuscular mycorrhizal (AM) fungi are integral to plant nutrient acquisition, carbon cycling, and ecosystem resilience, yet our knowledge of their biogeography is severely limited, especially in the Southern Hemisphere. Australia, despite its landmass and unique geoecological characteristics, has been vastly undersampled, leaving a significant gap in our understanding of AM fungal diversity and distribution. The AusAMF database was created to address this deficiency, the first release comprises AM fungal community data from 610 sampling locations across mainland Australia and Tasmania, collected between 2011 and 2023. Using standardised sampling, DNA extraction, sequencing methods and platforms, this database provides a robust resource for exploring spatial patterns in AM fungal diversity, community composition, and the ecological drivers shaping AM fungal biogeography. The AusAMF database will continue to be updated and maintain standardised approaches to facilitate future research into plant-mycorrhizal interactions, nutrient cycling, and to understand the broader role of AM fungi in ecosystem processes. The data here will provide the foundation for more informed management and conservation efforts in Australia while providing valuable data for global-scale analyses. Main types of variables containedGeoreferenced occurrence and abundance of high-throughput amplicon sequences of arbuscular mycorrhizal (AM) fungi. Spatial location and grainAustralia. Decimal degrees between 0.000001 - 0.1 resolution. Time period and grain2011-2023. Month and year of sampling. Major taxa and level of measurementArbuscular mycorrhizal fungi identified to family, genus, and virtual taxon (VT). Geographic occurrence and amplicon sequence abundance. Software formatInteract with data via online application. Dataset available as .csv files and raw sequencing data as .fastq files.

ecology↗

bioRxiv2020

Diversification slowdown in an evolutionary cul-de-sac

Analyzing diversification dynamics is key to understanding the past evolutionary history of clades that led to present-day biodiversity patterns. While such analyses are widespread in well-characterized groups of species, they are much more challenging in groups which diversity is mostly known through molecular techniques. Here, we use the largest global database on the small subunit (SSU) rRNA gene of Glomeromycotina, a subphylum of microscopic arbuscular mycorrhizal fungi that provide mineral nutrients to most land plants by forming one of the oldest terrestrial symbioses, to analyze the diversification dynamics of this clade in the past 500 million years (Myr). We perform a range of sensitivity analyses and simulations to control for potential biases linked to the nature of the data. We find that Glomeromycotina tend to have low speciation rates compared to other eukaryotes. After a peak of speciations between 200 and 100 Myr ago, they experienced an important decline in speciation rates toward the present. Such a decline could be at least partially related to a shrinking of their mycorrhizal niches and to their limited ability to colonize new niches. Our analyses identify patterns of diversification in a group of obligate symbionts of major ecological and evolutionary importance and illustrate that short molecular markers combined with intensive sensitivity analyses can be useful for studying diversification dynamics in microbial groups.

evolutionary biology↗

bioRxiv2020

Mycorrhizal symbiosis alleviates plant drought stress within and across plant generations via plasticity

O_LIPhenotypic plasticity is essential for organisms to adapt to local ecological conditions. It is expected that mutualistic interactions, such as arbuscular mycorrhizal (AM) symbiosis, mediate plant phenotypic plasticity, although it is not clear to what extent this plasticity may be heritable (i.e., transgenerational plasticity). C_LIO_LIWe tested for plant plasticity within- and across-generations in response to AM symbiosis and varying water availability in a full factorial experiment over two generations, using a genetically uniform line of a perennial apomictic herb, Taraxacum brevicorniculatum. We examined changes in phenotype, performance, and AM fungal colonization of the offspring throughout plant development. C_LIO_LIAM symbiosis and water availability triggered phenotypic changes during the life cycle of plants. Additionally, both triggered adaptive transgenerational effects, especially detectable during the juvenile stage of the offspring. Water deficit and absence of AM fungi caused concordant plant phenotypic modifications towards a "stress-coping phenotype", both within- and across-generations. AM fungal colonization of offspring was also affected by the parental environment. C_LIO_LIAM symbiosis can trigger within-generation and transgenerational plasticity in terms of functional traits related to resource-use acquisition and AM fungal colonization. Thus, transgenerational effects of mycorrhizal symbiosis are not limited to plant fitness, but also improve plants ability to cope with environmental stress. C_LI

ecology↗

bioRxiv2018

Constraints upon cheating emergence in mutualistic networks: evidence in the mycorrhizal symbiosis

O_LIWhile mutualisms are widespread and essential in ecosystem functioning, the emergence of uncooperative cheaters threatens their stability, unless there are functional or evolutionary mechanisms limiting cheaters interactions.\nC_LIO_LIHere, we evaluated the constraints upon mycoheterotrophic (MH) cheating plants in the mutualistic interaction network of autotrophic (AT) plants and arbuscular mycorrhizal fungi. For this purpose, we assembled a world-scale network of >25,000 interactions in order to investigate (i) the specialization and (ii) the phylogenetic distribution of MH or AT plants and their respective fungal partners.\nC_LIO_LIWe show that MH cheating repeatedly evolved in the vascular flora, suggesting low phylogenetic constraint for plants. However, MH cheaters are significantly more specialized than AT plants, and their fungi also appear more specialized and more closely related than fungi of AT plants, which suggest that cheaters are specifically isolated into modules by functional constraints\nC_LIO_LIThis unprecedented comparison of MH vs. AT plants thus reveals that MH cheating is most likely constrained by the specialization of phylogenetically conserved cheating-susceptible fungi, which suggests mechanisms for avoidance of these fungi. Beyond the mycorrhizal symbiosis, our approach highlights an empirical multiple-partners mutualistic system illustrating that the overall persistence of mutualism can be linked to functional constraints upon cheating emergences.\nC_LI

evolutionary biology↗