Marjo Helander
Docent, PhD
helander@utu.fi +358 29 450 4212 +358 50 409 7259 Vesilinnantie 5 Turku Office: 339 ORCID identifier: https://orcid.org/0000-0002-9759-4321 |
ecology; glyphosate; agroecology; fungal ecology; microbiota
I’m a
Turku University graduate (plant) ecologist. My main research interest are
plants, plant associated microbes (endophytic and epiphytic microbes,
mycorrhizal fungi, pathogens) and herbivores and their interactions. For over
twenty years, our model system has been grasses (genus Festuca) and their systemic seed transmitted endophytes (Epichloë sp.). During last decade my research
has focused more on agricultural systems and the effects of agrochemicals (glyphosate)
on non-target organisms. To answer our research questions we use long-term
common-garden and field experiments from where we get material and data for
laboratory analyses and modelling.
I have conducted
most of my research projects together with my husband Kari Saikkonen (Prof.,
Biodiversity Unit, University of Turku). Our research questions have taken us
to Arizona (Arizona State University, 1995-1997) and to the center of
grass-endophyte studies in Kentucky (2014) as well as to collect grass samples circumpolarly
(e.g. Greenland, Canada, Faroe Islands). We are actively collaborating with
several grass-endophyte research groups in Europe and North and South America.
I’m leading an Academy of Finland funded
research project (2017-2021) ‘Effects of glyphosate on non-target organisms’.
Glyphosate
is the most used pesticide globally. Its herbicidal activity is based on
inactivation of an enzyme of the shikimate metabolic pathway, and it thus kills
non-selectively herbaceous plants. It has been regarded harmless to animals and
humans, because the shikimate pathway does not occur in animals. However, it
can be found in many microbes. Thus, glyphosate may affect the microbial
activity and modify microbial community of the soil, plants and other
interacting organisms. In our project we take advantage of novel technologies
to examine microbiota in plants and animals, their interactions in plants via
phytohormone signaling pathways, and the effects of glyphosate on secondary
plant defense chemicals, plant performance, and performance and well-being of
both invertebrate and vertebrate animal model species. The
project leans on experimental field site (founded in 2014) simulating the
till/no-till cultivation using replicated plots with and without glyphosate
application in University of Turku Botanical Garden. We have chosen important
Finnish crops (broad horse bean, potato, meadow fescue, oat, strawberry) as
model plants in the field experiment to study indirect plant associated microbe
responses to glyphosate application. Direct glyphosate effects on herbivores
via food on life history traits and physiological responses and gut microflora
are studied on mealworms and Japanese quails. Indirect effects of glyphosate
via soil on herbivores are studied using Colorado potato beetles as model
organism. Our project is aiming to gain a holistic view of possible glyphosate
effects in the agroecosystem.
My teaching includes courses on plant-microbe-herbivore interactions, and agroecology and -evolution. Most of my teaching is, however, supervising bachelor's, master's and PhD thesis, which are usually part of our ongoing research projects.
- Betula pendula Roth. survival and growth in treeline is affected by genotype and environment (2025)
- Scientific Reports
(A1 Refereed original research article in a scientific journal) - Glyphosate-based herbicide increases the number of foraging trips but does not affect the homing of Bombus terrestris (2025)
- Apidologie
(A1 Refereed original research article in a scientific journal) - Effects of glyphosate and glyphosate-based herbicide on learning and memory of the buff-tailed bumblebee (Bombus terrestris) (2024)
- Entomologia Experimentalis et Applicata
(A1 Refereed original research article in a scientific journal) - Glyphosate residues in soil and phosphate fertilizer affect foliar endophytic microbial community composition and phytohormone levels in potato (2024)
- Phytobiomes journal
(A1 Refereed original research article in a scientific journal) - Greenhouse study and interviews indicate glyphosate residue via feed-feces-fertilizer route is a risk for horticultural producers using manure-based fertilizer (2024)
- Environmental Sciences Europe
(A1 Refereed original research article in a scientific journal) - Plant metabolic responses to soil herbicide residues differ under herbivory in two woodland strawberry genotypes (2024)
- Science of the Total Environment
(A1 Refereed original research article in a scientific journal) - Toward an integrated understanding of how extreme polar light regimes, hybridization, and light-sensitive microbes shape global biodiversity (2024)
- One Earth
(A1 Refereed original research article in a scientific journal) - Ecosystem consequences of herbicides: the role of microbiome (2023)
- Trends in Ecology and Evolution
(A2 Refereed review article in a scientific journal ) - Endophytic Beauveria bassiana induces biosynthesis of flavonoids in oilseed rape following both seed inoculation and natural colonization (2023)
- Pest Management Science
(A1 Refereed original research article in a scientific journal) - Endophytic Fungus Negatively Affects Salt Tolerance of Tall Fescue (2023)
- Journal of Fungi
(A1 Refereed original research article in a scientific journal) - Epichloë Endophytes Shape the Foliar Endophytic Fungal Microbiome and Alter the Auxin and Salicylic Acid Phytohormone Levels in Two Meadow Fescue Cultivars (2023)
- Journal of Fungi
(A1 Refereed original research article in a scientific journal) - Field-realistic acute exposure to glyphosate-based herbicide impairs fine-color discrimination in bumblebees (2023)
- Science of the Total Environment
(A1 Refereed original research article in a scientific journal) - Glyphosate and a glyphosate-based herbicide affect bumblebee gut microbiota (2023)
- FEMS Microbiology Ecology
(A1 Refereed original research article in a scientific journal) - Glyphosate-based herbicide use affects individual microbial taxa in strawberry endosphere but not the microbial community composition (2023)
- Journal of Applied Microbiology
(A1 Refereed original research article in a scientific journal) - Herbicide residues in soil decrease microbe-mediated plant protection (2023)
- Plant Biology
(A1 Refereed original research article in a scientific journal) - The effects of short-term glyphosate-based herbicide exposure on insect gene expression profiles (2023)
- Journal of Insect Physiology
(A1 Refereed original research article in a scientific journal) - A Glyphosate-Based Herbicide in Soil Differentially Affects Hormonal Homeostasis and Performance of Non-target Crop Plants (2022)
- Frontiers in Plant Science
(A1 Refereed original research article in a scientific journal) - Dark septate endophytes: mutualism from by-products? (2022)
- Trends in Plant Science
(B1 Non-refereed article in a scientific journal) - Does Glyphosate Affect the Human Microbiota? (2022)
- Life
(A1 Refereed original research article in a scientific journal) - Epichloë Endophyte-Promoted Seed Pathogen Increases Host Grass Resistance Against Insect Herbivory (2022)
- Frontiers in Microbiology
(A1 Refereed original research article in a scientific journal)