scholarly journals MycoRed: Betalain pigments enable in vivo real-time visualisation of arbuscular mycorrhizal colonisation

PLoS Biology ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. e3001326
Author(s):  
Alfonso Timoneda ◽  
Temur Yunusov ◽  
Clement Quan ◽  
Aleksandr Gavrin ◽  
Samuel F. Brockington ◽  
...  
Keyword(s):  
Crop Yields ◽  
Arbuscular Mycorrhizal ◽  
Crop Species ◽  
Fungal Colonisation ◽  
Visual Markers ◽  
Mycorrhizal Colonisation ◽  
Am Symbiosis ◽  
Colonisation Dynamics ◽  
Root Tissues

Arbuscular mycorrhiza (AM) are mutualistic interactions formed between soil fungi and plant roots. AM symbiosis is a fundamental and widespread trait in plants with the potential to sustainably enhance future crop yields. However, improving AM fungal association in crop species requires a fundamental understanding of host colonisation dynamics across varying agronomic and ecological contexts. To this end, we demonstrate the use of betalain pigments as in vivo visual markers for the occurrence and distribution of AM fungal colonisation by Rhizophagus irregularis in Medicago truncatula and Nicotiana benthamiana roots. Using established and novel AM-responsive promoters, we assembled multigene reporter constructs that enable the AM-controlled expression of the core betalain synthesis genes. We show that betalain colouration is specifically induced in root tissues and cells where fungal colonisation has occurred. In a rhizotron setup, we also demonstrate that betalain staining allows for the noninvasive tracing of fungal colonisation along the root system over time. We present MycoRed, a useful innovative method that will expand and complement currently used fungal visualisation techniques to advance knowledge in the field of AM symbiosis.

scholarly journals Silencing MdGH3-2/12 in apple reduces drought resistance by regulating AM colonization

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Dong Huang ◽  
Qian Wang ◽  
Zhijun Zhang ◽  
Guangquan Jing ◽  
Mengnan Ma ◽  
...  
Keyword(s):  
Drought Stress ◽  
Mycorrhizal Fungi ◽  
Crop Yields ◽  
Negative Impact ◽  
Arbuscular Mycorrhizal ◽  
Ros Scavenging ◽  
Crop Species ◽  
Relative Water ◽  
Am Symbiosis ◽  
Water Contents

AbstractDrought leads to reductions in plant growth and crop yields. Arbuscular mycorrhizal fungi (AMF), which form symbioses with the roots of the most important crop species, alleviate drought stress in plants. In the present work, we identified 14 GH3 genes in apple (Malus domestica) and provided evidence that MdGH3-2 and MdGH3-12 play important roles during AM symbiosis. The expression of both MdGH3-2 and MdGH3-12 was upregulated during mycorrhization, and the silencing of MdGH3-2/12 had a negative impact on AM colonization. MdGH3-2/12 silencing resulted in the downregulation of five genes involved in strigolactone synthesis, and there was a corresponding change in root strigolactone content. Furthermore, we observed lower root dry weights in RNAi lines under AM inoculation conditions. Mycorrhizal transgenic plants showed greater sensitivity to drought stress than WT, as indicated by their higher relative electrolytic leakage and lower relative water contents, osmotic adjustment ability, ROS scavenging ability, photosynthetic capacity, chlorophyll fluorescence values, and abscisic acid contents. Taken together, these data demonstrate that MdGH3-2/12 plays an important role in AM symbiosis and drought stress tolerance in apple.

Strigolactones: a cry for help in the rhizosphere

Botany ◽  
2011 ◽  
Vol 89 (8) ◽  
pp. 513-522 ◽  
Author(s):  
Juan A. López-Ráez ◽  
María J. Pozo ◽  
José M. García-Garrido
Keyword(s):  
Host Plant ◽  
Control Strategies ◽  
Arbuscular Mycorrhizal ◽  
Terrestrial Plants ◽  
Crop Species ◽  
Signalling Molecules ◽  
Fungal Partner ◽  
Cry For Help ◽  
Am Symbiosis

Arbuscular mycorrhizal (AM) symbiosis is a beneficial symbiosis established between fungi of the phylum Glomeromycota and over 80% of terrestrial plants, including most agricultural and horticultural crop species. AM symbiosis improves the nutritional status and fitness of the host plant and enables the plant to perform better under stressful conditions. As a result, when plants are growing under unfavourable conditions, they try to recruit their AM fungal partner in the soil. Symbiosis establishment requires a complex chemical dialogue between the two partners, in which signalling molecules such as the strigolactones play a key role. Under deficient nutrient conditions, the host plant increases the production of strigolactones to promote fungal development and symbiosis establishment (a “cry for help”). As a clue to host presence in the rhizosphere, strigolactones are also detected by other organisms, particularly root parasitic plants, and therefore promote a parasitic interaction. We review here the role of strigolactones and their interaction with other phytohormones during AM symbiosis, paying special attention to the implications of the chemical communication that takes place in the rhizosphere. Finally, we point out the potential use of this molecular dialogue as a target for developing new biological control strategies against deleterious organisms such as root parasitic weeds.

scholarly journals Transcriptomic analysis of field-droughted sorghum from seedling to maturity reveals biotic and metabolic responses

2019 ◽  
Vol 116 (52) ◽  
pp. 27124-27132 ◽  
Author(s):  
Nelle Varoquaux ◽  
Benjamin Cole ◽  
Cheng Gao ◽  
Grady Pierroz ◽  
Christopher R. Baker ◽  
...  
Keyword(s):  
Large Scale ◽  
Crop Yields ◽  
Arbuscular Mycorrhizal ◽  
Genotypic Differences ◽  
Transcriptomic Response ◽  
Stay Green ◽  
Delayed Senescence ◽  
Expression Of Genes ◽  
Large Scale Field ◽  
Root Tissues

Drought is the most important environmental stress limiting crop yields. The C4 cereal sorghum [Sorghum bicolor(L.) Moench] is a critical food, forage, and emerging bioenergy crop that is notably drought-tolerant. We conducted a large-scale field experiment, imposing preflowering and postflowering drought stress on 2 genotypes of sorghum across a tightly resolved time series, from plant emergence to postanthesis, resulting in a dataset of nearly 400 transcriptomes. We observed a fast and global transcriptomic response in leaf and root tissues with clear temporal patterns, including modulation of well-known drought pathways. We also identified genotypic differences in core photosynthesis and reactive oxygen species scavenging pathways, highlighting possible mechanisms of drought tolerance and of the delayed senescence, characteristic of the stay-green phenotype. Finally, we discovered a large-scale depletion in the expression of genes critical to arbuscular mycorrhizal (AM) symbiosis, with a corresponding drop in AM fungal mass in the plants’ roots.

Does mycorrhizal colonisation vary between maize and sunflower under limitations to radiation source or carbohydrate sink?

2018 ◽  
Vol 69 (10) ◽  
pp. 974
Author(s):  
Fernanda Covacevich ◽  
Julieta Martínez Verneri ◽  
Guillermo A. A. Dosio
Keyword(s):  
Radiation Source ◽  
Field Experiments ◽  
Arbuscular Mycorrhizal ◽  
Grain Filling ◽  
Reproductive Organs ◽  
Soluble Carbohydrates ◽  
Crop Species ◽  
Mycorrhizal Colonisation ◽  
Grain Filling Period ◽  
The Relationship

The aim of this work was to analyse and compare indigenous arbuscular mycorrhizal colonisation (AMC) in relation to growth and total soluble carbohydrates (TSC) in two major, physiologically contrasting crop species: maize (Zea mays L.) and sunflower (Helianthus annuus L.). In order to promote contrasting TSC concentrations, we modified the radiation source by shading and the carbohydrate sink by manipulating reproductive sinks at different phenological stages during the grain-filling period in two field experiments. We assessed plant dry matter, TSC in stems, and root AMC from flowering until final harvest. AMC during the grain-filling period decreased in maize and increased in sunflower. A sink limitation increased AMC in maize, and reduced it in sunflower. A source limitation decreased AMC in both species, especially in sunflower. AMC was positively related to TSC in maize, but negatively in sunflower. The relationship was affected by shading in sunflower, but not in maize. In both species, a different linear model described the relationship between AMC and TSC in plants submitted to the removal of the reproductive organs. The results highlight the role of carbohydrates in mediating mycorrhizal formation, and show for the first time the opposite AMC–TSC relationships in maize and sunflower.

Mechanisms Underlying Establishment of Arbuscular Mycorrhizal Symbioses

2018 ◽  
Vol 56 (1) ◽  
pp. 135-160 ◽  
Author(s):  
Jeongmin Choi ◽  
William Summers ◽  
Uta Paszkowski
Keyword(s):  
Lateral Root ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Land Plants ◽  
Fixed Carbon ◽  
Lateral Root Development ◽  
Sister Clade ◽  
Am Symbiosis ◽  
Root Tissues ◽  
Chitin Receptor

Most land plants engage in mutually beneficial interactions with arbuscular mycorrhizal (AM) fungi, the fungus providing phosphate and nitrogen in exchange for fixed carbon. During presymbiosis, both organisms communicate via oligosaccharides and butenolides. The requirement for a rice chitin receptor in symbiosis-induced lateral root development suggests that cell division programs operate in inner root tissues during both AM and nodule symbioses. Furthermore, the identification of transcription factors underpinning arbuscule development and degeneration reemphasized the plant's regulatory dominance in AM symbiosis. Finally, the finding that AM fungi, as lipid auxotrophs, depend on plant fatty acids (FAs) to complete their asexual life cycle revealed the basis for fungal biotrophy. Intriguingly, lipid metabolism is also central for asexual reproduction and interaction of the fungal sister clade, the Mucoromycotina, with endobacteria, indicative of an evolutionarily ancient role for lipids in fungal mutualism.

Improved Plant Diversity as a Strategy to Increase Available Soil Phosphorus

2019 ◽  
Vol 103 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Carlos Crusciol ◽  
João Rigon ◽  
Juliano Calonego ◽  
Rogério Soratto
Keyword(s):  
Crop Yields ◽  
Soil Phosphorus ◽  
Cropping System ◽  
P Availability ◽  
P Fractions ◽  
Crop Species ◽  
Soil P ◽  
Residue Decomposition ◽  
Available Soil Phosphorus ◽  
Crop Residue Decomposition

Some crop species could be used inside a cropping system as part of a strategy to increase soil P availability due to their capacity to recycle P and shift the equilibrium between soil P fractions to benefit the main crop. The release of P by crop residue decomposition, and mobilization and uptake of otherwise recalcitrant P are important mechanisms capable of increasing P availability and crop yields.

scholarly journals High probability of yield gain through conservation agriculture in dry regions for major staple crops

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Su ◽  
Benoit Gabrielle ◽  
Damien Beillouin ◽  
David Makowski
Keyword(s):  
Management Practices ◽  
Crop Yields ◽  
Positive Impact ◽  
Relative Yield ◽  
Conservation Agriculture ◽  
Conventional Tillage ◽  
Machine Learning Algorithms ◽  
Agricultural Practice ◽  
Crop Species ◽  
Yield Gain

AbstractConservation agriculture (CA) has been promoted to mitigate climate change, reduce soil erosion, and provide a variety of ecosystem services. Yet, its impacts on crop yields remains controversial. To gain further insight, we mapped the probability of yield gain when switching from conventional tillage systems (CT) to CA worldwide. Relative yield changes were estimated with machine learning algorithms trained by 4403 paired yield observations on 8 crop species extracted from 413 publications. CA has better productive performance than no-till system (NT), and it stands a more than 50% chance to outperform CT in dryer regions of the world, especially with proper agricultural management practices. Residue retention has the largest positive impact on CA productivity comparing to other management practices. The variations in the productivity of CA and NT across geographical and climatical regions were illustrated on global maps. CA appears as a sustainable agricultural practice if targeted at specific climatic regions and crop species.

scholarly journals Target of rapamycin, PvTOR, is a key regulator of arbuscule development during mycorrhizal symbiosis in Phaseolus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manoj-Kumar Arthikala ◽  
Kalpana Nanjareddy ◽  
Lourdes Blanco ◽  
Xóchitl Alvarado-Affantranger ◽  
Miguel Lara
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Target Of Rapamycin ◽  
Mycorrhizal Symbiosis ◽  
Energy Status ◽  
Symbiotic Associations ◽  
Expression Of Genes ◽  
Fungal Symbiosis ◽  
Am Fungus ◽  
Am Symbiosis

AbstractTarget of rapamycin (TOR) is a conserved central growth regulator in eukaryotes that has a key role in maintaining cellular nutrient and energy status. Arbuscular mycorrhizal (AM) fungi are mutualistic symbionts that assist the plant in increasing nutrient absorption from the rhizosphere. However, the role of legume TOR in AM fungal symbiosis development has not been investigated. In this study, we examined the function of legume TOR in the development and formation of AM fungal symbiosis. RNA-interference-mediated knockdown of TOR transcripts in common bean (Phaseolus vulgaris) hairy roots notably suppressed AM fungus-induced lateral root formation by altering the expression of root meristem regulatory genes, i.e., UPB1, RGFs, and sulfur assimilation and S-phase genes. Mycorrhized PvTOR-knockdown roots had significantly more extraradical hyphae and hyphopodia than the control (empty vector) roots. Strong promoter activity of PvTOR was observed at the site of hyphal penetration and colonization. Colonization along the root length was affected in mycorrhized PvTOR-knockdown roots and the arbuscules were stunted. Furthermore, the expression of genes induced by AM symbiosis such as SWEET1, VPY, VAMP713, and STR was repressed under mycorrhized conditions in PvTOR-knockdown roots. Based on these observations, we conclude that PvTOR is a key player in regulating arbuscule development during AM symbiosis in P. vulgaris. These results provide insight into legume TOR as a potential regulatory factor influencing the symbiotic associations of P. vulgaris and other legumes.

Integrating physiological, community, and evolutionary perspectives on the arbuscular mycorrhizal symbiosis

Botany ◽  
2014 ◽  
Vol 92 (4) ◽  
pp. 241-251 ◽  
Author(s):  
Ylva Lekberg ◽  
Roger T. Koide
Keyword(s):  
Evolutionary Biology ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Partner Choice ◽  
Mycorrhizal Symbiosis ◽  
Physiological Processes ◽  
Resource Transfers ◽  
Am Symbiosis ◽  
Controlled Environments ◽  
Natural Settings

Our knowledge of arbuscular mycorrhizal (AM) function is largely based on results from short-term studies in controlled environments. While these have provided many important insights into the potential effects of the symbiosis on the two symbionts and their communities, they may have also inadvertently led to faulty assumptions about the function of the symbiosis in natural settings. Here we highlight the consequences of failing to consider the AM symbiosis from the perspectives of community ecology and evolutionary biology. Also, we argue that by distinguishing between physiological and evolutionary viewpoints, we may be able to resolve controversies regarding the mutualistic vs. parasitic nature of the symbiosis. Further, while most AM research has emphasized resource transfers, primarily phosphate and carbohydrate, our perceptions of parasitism, cheating, bet-hedging, and partner choice would most likely change if we considered other services. Finally, to gain a fuller understanding of the role of the AM symbiosis in nature, we need to better integrate physiological processes of plants and their AM fungi with their naturally occurring temporal and spatial patterns. It is our hope that this article will generate some fruitful discussions and make a contribution toward this end.

Effects of temperature rise (+5°C) on millet growth and mycorrhization and soil microbial community of culture

2021 ◽  
Author(s):  
Sally Diatta ◽  
Hassna Mboup-Founoune ◽  
Sidy Diakhaté ◽  
Diégane Diouf
Keyword(s):  
Microbial Community ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Crop Yields ◽  
Pennisetum Glaucum ◽  
Agricultural Practices ◽  
Arbuscular Mycorrhizal ◽  
Sub Saharan Africa ◽  
Soil Fertility Management ◽  
Vegetation Growth

<p>Our planet is marked by significant climatic variations, particularly with the warming of temperatures and the variation in rainfall. In sub-Saharan Africa, the impacts of climate change are more pronounced because agriculture is highly dependent on climate, hence its vulnerability to climate variability (Vanluwe et al., 2011). In the context of changing environmental conditions, the use of innovative agricultural practices to contribute to plant adaptation is necessary to support food security challenges. Agroecological practices to improve crop yields and sustainable soil fertility management. Soil is the main reservoir of biodiversity as it hosts a very high diversity of interacting living species, which can be distinguished according to their size, macrofauna, mesofauna and microorganisms that constitute a particularly important component of soil (Brady and Weil, 2002), particularly for the provision of ecosystem services to humans. This work is therefore interested in studying the contribution of arbuscular mycorrhizal fungi (AMF) to the growth of millet (<em>Pennisetum glaucum</em>) under warmer temperature conditions and the behaviour of microbial community in soil of millet growing.</p><p>Millet is grown in a plant climate chamber and inoculated with a selected mycorrhizal strain.  These millet growing conditions were carried out in two different temperatures: 32°C (normal temperature) and 37°C (warmer temperature).</p><p>The results showed that in conditions of warmer temperature the inoculation induced a significant vegetative growth of millet even with a low intensity of mycorrhization and so it improves microbial nutrient mineralization mediate vegetation growth.</p><p>In soil of millet growing, a significant increase in microbial biomass with 42.7 in warmer temperature condition compared to control temperature 16.7. Results of DGGE shows also a soil abundance and SMB diversity of the total fungal community was noted under warmer temperature condition.</p><p>This study showed that climate variation may affect soil symbiosis but not the potential for promoting plant growth of fungi. The use of arbuscular mycorrhizal fungi on the one hand as a biofertilizer can be an alternative in the context of reducing chemical inputs in agriculture and developing ecologically intensive agriculture (EIA) and on the other hand an adaptive practice  to apprehend the predicted climate changes.</p>

Sign in / Sign up

Export Citation Format

Share Document