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The arbuscular mycorrhizal fungi (AMFs) are obligate root symbionts in the subphylum Glomeromycotina that can benefit land plants by increasing their soil nutrient uptake in exchange for photosynthetically fixed carbon sources. To date, annotated genome data from representatives of the AMF orders Glomerales, Diversisporales and Archaeosporales have shown that these organisms have large and highly repeated genomes, and no genes to produce sugars and fatty acids. This led to the hypothesis that the most recent common ancestor (MRCA) of Glomeromycotina was fully dependent on plants for nutrition. Here, we aimed to further test this hypothesis by obtaining annotated genome data from a member of the early diverging order Paraglomerales ( Paraglomus occultum ). Genome analyses showed this species carries a 39.6 Mb genome and considerably fewer genes and repeats compared to most AMF relatives with annotated genomes. Consistent with phylogenies based on ribosomal genes, our phylogenetic analyses suggest P. occultum as the earliest diverged branch within Glomeromycotina. Overall, our analyses support the view that the MRCA of Glomeromycotina carried hallmarks of obligate plant biotrophy. The small genome size and content of P. occultum could either reflect adaptive reductive processes affecting some early AMF lineages, or indicate that the high gene and repeat family diversity thought to drive AMF adaptability to host and environmental change was not an ancestral feature of these prominent plant symbionts.
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Arbuscular mycorrhizal Fungi as Inspiration for Sustainable Technology
This review illuminates established knowledge of root–arbuscular mycorrhizal fungi (AMF)–plant mutualism to study the uptake of phosphorus (P) as a critical element for plant nutrition. We focus on P cycling, underscoring the role of AMF in enhancing P acquisition and plant resilience in the rhizosphere. The role(s) of plant roots, root exudates, and biomolecules in relevant soil processes is emphasized in this manuscript. Enhancing P uptake efficiency through AMF interaction presents a promising avenue for sustainable agriculture, with future research opportunities focusing on understanding underlying mechanisms and developing innovative technologies as a need to transition from the use of AMF as a biofertilizer or as an inoculation alternative for seeds to being an inspiration for the development of technology adapted to different crops. This is important to promote responsible agricultural practices and improve crop yields. We provide definitions of key terms and concepts for one of the best-known natural sustainable phosphorus systems. This manuscript illuminates and aims to inspire technology development to overcome the challenge of plant nutrition under P scarcity conditions.
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- Award ID(s):
- 2019435
- PAR ID:
- 10611714
- Publisher / Repository:
- MDPI
- Date Published:
- Journal Name:
- Encyclopedia
- Volume:
- 4
- Issue:
- 3
- ISSN:
- 2673-8392
- Page Range / eLocation ID:
- 1188 to 1200
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract The presence of Arbuscular Mycorrhizal Fungi (AMF) in vascular land plant roots is one of the most ancient of symbioses supporting nitrogen and phosphorus exchange for photosynthetically derived carbon. Here we provide a multi-scale modeling approach to predict AMF colonization of a worldwide crop from a Recombinant Inbred Line (RIL) population derived fromSorghum bicolorandS. propinquum. The high-throughput phenotyping methods of fungal structures here rely on a Mask Region-based Convolutional Neural Network (Mask R-CNN) in computer vision for pixel-wise fungal structure segmentations and mixed linear models to explore the relations of AMF colonization, root niche, and fungal structure allocation. Models proposed capture over 95% of the variation in AMF colonization as a function of root niche and relative abundance of fungal structures in each plant. Arbuscule allocation is a significant predictor of AMF colonization among sibling plants. Arbuscules and extraradical hyphae implicated in nutrient exchange predict highest AMF colonization in the top root section. Our work demonstrates that deep learning can be used by the community for the high-throughput phenotyping of AMF in plant roots. Mixed linear modeling provides a framework for testing hypotheses about AMF colonization phenotypes as a function of root niche and fungal structure allocations.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/encyclopedia4030077
