Root fungal endophytes improve the growth of antarctic plants through an enhanced nitrogen acquisition
Mutualistic symbiosis with fungal endophytes has been suggested as a possible mechanism for extreme environment colonization by Antarctic vascular plants. Fungal endophytes improve plant stress tolerance and performance by increasing plant hormone production and the uptake of water and nutrients. Ho...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Other/Unknown Material |
| Language: | unknown |
| Published: |
PeerJ
2018
|
| Subjects: | |
| Online Access: | http://dx.doi.org/10.7287/peerj.preprints.26774v1 https://peerj.com/preprints/26774v1.pdf https://peerj.com/preprints/26774v1.xml https://peerj.com/preprints/26774v1.html |
| Summary: | Mutualistic symbiosis with fungal endophytes has been suggested as a possible mechanism for extreme environment colonization by Antarctic vascular plants. Fungal endophytes improve plant stress tolerance and performance by increasing plant hormone production and the uptake of water and nutrients. However, there are still gaps regarding the mechanisms by which these process ocurr. This work explores the role of root fungal endophytes in the production of exolytic enzymes involved in endophyte-mediated mineralization and nutrient uptake, as well as their impact on the performance of Antarctic plants. Hence, we evaluated the ability of fungal endophytes isolated from the two native Antarctic vascular plants, Colobanthus quitensis and Deschampsia antarctica , to enzymatically degrade different nutrient sources, mediate nitrogen mineralization and enhance growth of the host plant. Single-spore derived isolates were identified using molecular and morphological approaches. Penicillium chrysosgenum and Penicillium brevicompactum were identified as the dominant root endophytes in C. quitensis and D. antarctica , respectively. Root endophytes exhibited hydrolytic and oxidative enzymatic activities involved in carbohydrate or protein breakdown and phosphorus solubilization. In addition, the rates and porcentages of nitrogen mineralization, as well as the final total biomass were significantly higher in C. quitensis and D. antarctica individuals with root endophytes relative to those without endophytes. Our findings suggest that root endophytes exert a pivotal ecological role based not only on their capability to breakdown different nutrient sources but also accelerating nitrogen mineralization, improving nutrient acquisition and promoting plant growth in limited nutrient soils in Antarctic terrestrial ecosystems |
|---|