| 1. |
- Aleklett, Kristin, et al.
(författare)
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Build your own soil : exploring microfluidics to create microbial habitat structures
- 2018
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Ingår i: ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 12:2, s. 312-319
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Forskningsöversikt (refereegranskat)abstract
- Soil is likely the most complex ecosystem on earth. Despite the global importance and extraordinary diversity of soils, they have been notoriously challenging to study. We show how pioneering microfluidic techniques provide new ways of studying soil microbial ecology by allowing simulation and manipulation of chemical conditions and physical structures at the microscale in soil model habitats.The ISME Journal advance online publication, 14 November 2017; doi:10.1038/ismej.2017.184.
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| 2. |
- Aleklett, Kristin, et al.
(författare)
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Effects of organic amendments with various nitrogen levels on arbuscular mycorrhizal fungal growth
- 2012
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Ingår i: Applied Soil Ecology. - : Elsevier BV. - 0929-1393. ; 60, s. 71-76
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Tidskriftsartikel (refereegranskat)abstract
- Arbuscular mycorrhizal fungi (AMF) are plant symbionts capable of enhancing nutrient uptake and improving soil structure. These features have brought AMF into focus as a component of soil restoration practices in ecosystems with degraded or highly eroded soils. It has been suggested that increasing the levels of organic material in the soil will enhance the production of AMF biomass, and that organic amendments with high concentrations of nitrogen (N) generate the largest increases in AMF growth. We tested the effects of different organic amendments and N sources on AMF responses in a natural sand dune system and pot cultures of Zea Mays L. The in-growth of AMF was measured as relative biomass through analyses of signature phospholipid fatty acids (PLFA) and neutral lipid fatty acids (NLFA) from mesh bags with different treatments. In the field, results showed a significant positive effect in AMF growth from adding a naturally N-rich organic amendment (alfalfa). Amendments of the low-N organic amendment (barley straw) produced no positive effect, and the effect was negative when ammonium nitrate (NH4NO3) was added to the barley straw to simulate the N concentrations of alfalfa. Saprophytic fungi, on the other hand, were stimulated by additions of NH4NO3. In greenhouse conditions, alfalfa and yeast extract were found to have a similar effect on AMF growth when added proportionally to their N content, even though their mass and texture are distinct. These results suggest the N content in organic amendments does play a role in its effect on AMF growth. There are also indications that the organic or inorganic nature of the N could determine its effect on AMF growth, possibly through interactions with the surrounding microbial community. This aspect requires further investigation. (C) 2012 Elsevier B.V. All rights reserved.
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| 3. |
- Aleklett, Kristin, et al.
(författare)
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Fungal foraging behaviour and hyphal space exploration in micro-structured Soil Chips
- 2021
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Ingår i: The Isme Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370.
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Tidskriftsartikel (refereegranskat)abstract
- How do fungi navigate through the complex microscopic maze-like structures found in the soil? Fungal behaviour, especially at the hyphal scale, is largely unknown and challenging to study in natural habitats such as the opaque soil matrix. We monitored hyphal growth behaviour and strategies of seven Basidiomycete litter decomposing species in a micro-fabricated "Soil Chip" system that simulates principal aspects of the soil pore space and its micro-spatial heterogeneity. The hyphae were faced with micrometre constrictions, sharp turns and protruding obstacles, and the species examined were found to have profoundly different responses in terms of foraging range and persistence, spatial exploration and ability to pass obstacles. Hyphal behaviour was not predictable solely based on ecological assumptions, and our results obtained a level of trait information at the hyphal scale that cannot be fully explained using classical concepts of space exploration and exploitation such as the phalanx/guerrilla strategies. Instead, we propose a multivariate trait analysis, acknowledging the complex trade-offs and microscale strategies that fungal mycelia exhibit. Our results provide novel insights about hyphal behaviour, as well as an additional understanding of fungal habitat colonisation, their foraging strategies and niche partitioning in the soil environment.
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| 4. |
- Aleklett Kadish, Kristin
(författare)
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Community assembly and stability in the root microbiota during early plant development
- 2022
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Little is known about how community composition in the plant microbiome is affected by events in the life of a plant. For example, when the plant is exposed to soil, microbial communities may be an important factor in root community assembly. We conducted two experiments asking whether the composition of the root microbiota in mature plants could be determined by either the timing of root exposure to microbial communities or priority effects by early colonizing microbes. Timing of microbial exposure was manipulated through an inoculation experiment, where plants of different ages were exposed to a common soil inoculum. Priority effects were manipulated by challenging roots with established microbiota with an exogenous microbial community. Results show that even plants with existing microbial root communities were able to acquire new microbial associates, but that timing of soil exposure affected root microbiota composition for both bacterial and fungal communities in mature plants. Plants already colonized were only receptive to colonizers at 1 week post-germination. Our study shows that the timing of soil exposure in the early life stages of a plant is important for the development of the root microbiota in mature plants.
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| 5. |
- Aleklett Kadish, Kristin
(författare)
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Fungal behaviour: a new frontier in behavioural ecology
- 2021
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Ingår i: Trends in ecology & evolution. - : Elsevier BV. - 0169-5347 .- 1872-8383. ; 36, s. 787-796
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Forskningsöversikt (refereegranskat)abstract
- As human beings, behaviours make up our everyday lives. What we do from the moment we wake up to the moment we go back to sleep at night can all be classified and studied through the concepts of behavioural ecology. The same applies to all vertebrates and, to some extent, invertebrates. Fungi are, in most people's eyes perhaps, the eukaryotic multicellular organisms with which we humans share the least commonalities. However, they still express behaviours, and we argue that we could obtain a better understanding of their lives - although they are very different from ours - through the lens of behavioural ecology. Moreover, insights from fungal behaviour may drive a better understanding of behavioural ecology in general.
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| 6. |
- Andersen, Christian B., et al.
(författare)
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Pythium oligandrum induces growth promotion in starch potato without significantly altering the rhizosphere microbiome
- 2024
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Ingår i: Applied Soil Ecology. - 0929-1393. ; 199
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Tidskriftsartikel (refereegranskat)abstract
- Plant health promoting organisms, including microbial biological control agents, are of increasing importance for the development of more sustainable agriculture. To understand the function of these microbes as biological control agents under field conditions and their overall impact on soil and plant health, we need to learn more about the impact of plant beneficial microbes on the rhizosphere microbiome of crops such as potato. The plant beneficial oomycete Pythium oligandrum has previously been reported both as a biocontrol agent and as a plant growth promoter, or biostimulant, in several crop species. To investigate the potential of P. oligandrum as a biostimulant in potato, we performed a series of controlled-environment bioassays in three cultivars. We showed that biostimulation of potato by P. oligandrum is plant genotype-specific. We confirmed the biostimulation by P. oligandrum in the starch potato cultivar Kuras under field conditions. We further investigated the effects of P. oligandrum on the potato rhizosphere microbiome, sampling individual potato plants at three time points over the growing season (representing the vegetative growth phase, flowering, and the onset of senescence). Metabarcoding using ITS and 16S amplicon sequencing revealed no significant overall effect of P. oligandrum application on the bacterial and fungal rhizosphere communities. However, some genera were significantly differentially abundant after P. oligandrum application, including some classified as plant-beneficial microbes. We conclude that P. oligandrum has a cultivar-dependent growth-promoting effect in potato and only minor effects on the rhizosphere microbiome.
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| 7. |
- Hammer, Edith C., et al.
(författare)
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Hyphal exploration strategies and habitat modification of an arbuscular mycorrhizal fungus in microengineered soil chips
- 2024
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Ingår i: Fungal Ecology. - 1754-5048. ; 67
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Tidskriftsartikel (refereegranskat)abstract
- Arbuscular mycorrhizal fungi (AMF) are considered ecosystem engineers, but the interactions of their mycelium with their immediate surroundings are largely unknown. In this study, we used microfluidic chips, simulating artificial soil structures, to study foraging strategies and habitat modification of Rhizophagus irregularis symbiotically associated to carrot roots. AMF hyphae foraged over long distances in nutrient-void spaces, preferred straight over tortuous passages, anastomosed and showed strong inducement of branching when encountering obstacles. We measured bi-directional transport of cellular content inside active hyphae and documented strategic allocation of biomass within the mycelium via cytoplasm retraction from inefficient paths. R. irregularis modified pore-spaces in the chips by clogging pores with irregularly shaped spores. We suggest that studying AMF hyphal behaviour in spatial settings can explain phenomena reported at bulk scale such as AMF modification of water retention in soils. The use of microfluidic soil chips in AMF research opens up novel opportunities to study their ecophysiology and interactions with both biotic and abiotic factors.
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| 8. |
- Hammer, Edith C., et al.
(författare)
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The secret life of fungi : how they use ingenious strategies to forage underground
- 2021
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Ingår i: The Conversation. - 2201-5639.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- When you think of fungi, you’ll probably picture a huddle of chubby brown mushrooms, or the large, red-capped toadstools you stumble across in the woods. In doing so, you’re reducing fungi to their reproductive organs – tasty or striking as they may often be.
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| 9. |
- Lankinen, Åsa, et al.
(författare)
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Challenges and opportunities for increasing the use of low-risk plant protection products in sustainable production. A review
- 2024
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Ingår i: Agronomy for Sustainable Development. - : Springer. - 1774-0746 .- 1773-0155. ; 44:2
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Forskningsöversikt (refereegranskat)abstract
- Plant production systems worldwide are struggling to meet the diverse and increasing needs of humankind while also facing challenges such as climate change and biodiversity loss. This, combined with the desirable transition from the use of conventional pesticides to more sustainable plant protection solutions, has led to an urgent, and increasing, need for low-risk plant protection products (PPPs) to be developed, applied, and integrated into management practices across all types of plant production systems. Despite a high demand from end users and consumers together with joint political goals at the EU level to replace conventional pesticides, the number of low-risk PPPs on the European market remains low, in comparison to synthetic agrochemicals. In this review, we summarize knowledge about the policy, technical, and administrative issues hampering the process of bringing new low-risk PPPs to the European market. We present an overview of the challenges in using the low-risk PPPs that are currently available within the EU agricultural, horticultural, and forestry sectors. We describe the variation in modes of action and the limitations associated with different application techniques and give concrete examples of problems and solutions from Swedish plant production sectors, in contrast to global perspectives as demonstrated by examples from African agriculture. Finally, we conclude that trans-sectoral, multi-actor approaches are required and provide suggestions on how to address the remaining knowledge gaps related to efficiency, application, and economics of low-risk PPP use in Integrated Pest Management (IPM) solutions for plant protection to improve future food security in Europe.
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| 10. |
- Mafla-Endara, Paola Micaela, et al.
(författare)
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Microfluidic chips provide visual access to in situ soil ecology
- 2021
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- Microbes govern most soil functions, but investigation of these processes at the scale of their cells has been difficult to accomplish. Here we incubate microfabricated, transparent ‘soil chips’ with soil, or bury them directly in the field. Both soil microbes and minerals enter the chips, which enables us to investigate diverse community interdependences, such as inter-kingdom and food-web interactions, and feedbacks between microbes and the pore space microstructures. The presence of hyphae (‘fungal highways’) strongly and frequently increases the dispersal range and abundance of water-dwelling organisms such as bacteria and protists across air pockets. Physical forces such as water movements, but also organisms and especially fungi form new microhabitats by altering the pore space architecture and distribution of soil minerals in the chip. We show that soil chips hold a large potential for studying in-situ microbial interactions and soil functions, and to interconnect field microbial ecology with laboratory experiments.
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