Endofyyttisten bakteeriyhteisöjen diversiteetti ja toiminta arktisissa ekosysteemeissä.
Päärahoittaja
Rahoittajan antama koodi/diaarinumero: 292776
Päärahoittajan myöntämä tuki (€)
- 191 123,00
Rahoitusohjelma
Hankkeen aikataulu
Hankkeen aloituspäivämäärä: 01.09.2015
Hankkeen päättymispäivämäärä: 31.12.2017
Tiivistelmä
Arctic and subarctic ecosystems cover 22% of the earth's terrestrial surface, but remain poorly characterized. For example, the factors affecting vegetation dynamics and colonization of new areas, and consequently, impact on soil functioning, are not well understood. Plant microbe-interactions are likely an important factor in these processes. Endophytic bacteria non-pathogenic and inhabit internal tissues of their plant hosts. Awareness of the abundance and potential benefits of endophytes has grown rapidly in recent years, but most of the research focuses in temperate climate zones, and only very limited data is available from cold climates. Our recent work on three arctic plant species revealed a diverse community of endophytic bacteria. These bacteria were mainly psychrotolerant, closely related to bacteria from other cold biomes, and several endobacterial groups were host plant specific. Functional analysis indicated divergent metabolic profiles for these host-specific bacteria. Building on these data, the current project addresses comprehensively the selection, dynamics and functioning of the arctic endophytic bacterial communities. The main research hypotheses are that (1) the endophytic bacterial communities are dynamic and integral part of their host plants in all life stages, (2) part of the endobacterial flora is carried in seeds and have a role in seedling establishment, and that (3) plants actively select complementing endobacterial companions from the rhizosphere. The study focuses on five arcto-alpine plant species, with main focus on Oxyria digyna. The study sites are located in Kilpisjärvi (low arctic), Ny-Alesund (high arctic) and the Austrian Alps (temperate alpine). The approach addresses phylogenetic and functional community diversity. The phylogenetic diversity is analyzed by community fingerprinting and targeted pyrosequencing. The functional diversity will be analyzed from key samples by combined metagenomics and by metaproteomics and/or with functional microarrays. The molecular work is complemented with bacterial isolations and plant-bacteria bioassays. Endobacterial isolation and amplification methods are optimized prior to analyses. The project will provide data on bacterial communities and their functioning in different plant tissues and developmental stages, in different seasons and in different cold climate zones, and will simultaneously expand our knowledge on yet poorly known aspect of arctic biodiversity.
