The proposed project aims to improve our understanding on the mechanisms underlying phenotypic variation in red fescue aggregate and the potential responses to climate change by targeting the following questions. 1) What is the relative importance of phenotypic plasticity and heritable variation in ecologically relevant fescue traits within and among populations and geographic locations at different latitudes? 2) What is the role of defensive mutualism provided by endophytic Epichloë fungi in adaptive radiation of fescue? 3) How the defensive mutualism is regulated by the hormonal cross-talk between the fungus and the host grass and the expression of fungal genes driving alkaloid production? 4) What is the relative importance of changes in DNA sequence and epigenetic modifications in gene expression and phenotypic differences in flowering time of fescue and fungal alkaloid production? 5) And finally, what is the relative importance of these mechanisms underlying adaptive evolution of red fescue aggregate to temperature and seasonal changes in day length in changing climate?
We approach the presented research questions in three steps in three work packages (WPs). In WP1, we’ll examine (a) morphological characters, (b) ecologically relevant red fescue traits (flowering time), (c) phytohormones and (d) alkaloids from the ongoing reciprocal transplant experiment. WP2 focuses identifying genes encoding flowering time and alkaloid production. In WP3 we’ll first quantify epigenetic modifications in the genes encoding flowering time of the host and alkaloid production of the endophytic fungus, and then follow changes in the expression and function of the genes.
The proposed research leans strongly on utilizing Festuca rubra plants in the reciprocal transplant experiment established during the last four years in PI’s past Academy of Finland funded project (2011-14). The effects of temperature and day length will be tested, in addition to transplant experiment in Spain and two locations in Finland, by growing parental plants in mini-greenhouses which allow us to explicitly separate the responses of experimental organisms to light and temperature.
The project will be carried out in Natural Resources Institute Finland (Luke) in collaboration with researchers in the Universities of Helsinki, Jyväskylä and Turku, and Instituto de Recursos Naturales y Agrobiologıa, CSIC, Spain. Kevo Subarctic Research Institute and the Botanical Garden of University of Turku provide excellent greenhouses and common gardens for the empirical ecology, whilst Natural Resources Institute Finland offers fully equipped laboratories for the work on molecular ecology.
Applicability and utilization potential of the research results
Applications of the research are related to grass production in changing climate. Understanding mechanisms underlying variation, heritability and stability of cultivar traits are required to develop the best grass cultivars in changing environment. We have knowhow to manipulatively generate desired endophyte strain-grass combinations in breeding, but (a) genotypic interplay between the endophyte and the host plant, (b) the symbiotum responses to different environments (genotype x genotype x environment interactions) or (c) heritable epigenetic variability have been barely touched. Thus, we lack essential knowledge whether the treatments contribute the phenotype of the cultivar via epigenetic modifications. Such innovations potentially have the greatest value for plant breeders, seed dealers and end-users.
Economical value of systemic grass-endophytes related to forage quality and biocontrol has already been widely recognized in agriculture and turf grass industry in the USA and New Zealand. Thus, we propose that grass-endophytes could be utilized contributing the implementation of agronomic and environmental policies in Europe as well.
Gundel, P. E., L. I. Pérez, M. Helander and K. Saikkonen (2013) Symbiotically Modified Organisms: non-toxic fungal endophytes in grasses. Trends in Plant Science 18: 420-427.
Saikkonen, K., K. Taulavuori, T. Hyvönen, P. E. Gundel, C. E. Hamilton, I. Vänninen, A. Nissinen and M. Helander (2012) Climate change-driven species’ range shifts filtered by photoperiodism. Nature Climate Change 2: 239–242, doi:10.1038/nclimate1430.
Saikkonen, K, C.A. Young, M. Helande and C.L. Schardl (submitted ms.) Endophytic Epichloë species and their grass hosts: from evolution to applications. Plant Molecular Biology.