Arbuscular mycorrhizal (AM) fungi: Potential role in sustainable agriculture

Author(s):  
Khirood Doley ◽  
Mahesh Borde
2011 ◽  
Vol 9 (2) ◽  
pp. 80-94
Author(s):  
Oksana Y Shtark ◽  
Aleksey U Borisov ◽  
Vladimir A Zhukov ◽  
Timofey A Nemankin ◽  
Igor A Tikhonovich

Leguminous plants have a genetic system that provides interaction with different beneficial soil microorganisms (BSM). The system has been formed on the basis of the genetic mechanisms that had arisen during the co-evolution of plants with arbuscular-mycorrhizal (AM) fungi and appeared to provide pre-adaptations for further evolution of interaction with various BSM. A concept of the use of BSM in sustainable agriculture is proposed, which postulates an establishment of the multi-component beneficial plant-microbe communities based on varieties of legumes with high potential for interaction with the BSM. 


2021 ◽  
Author(s):  
Lorenzo Borghi ◽  
Claudio Screpanti ◽  
Alexandre Lumbroso ◽  
Mathilde Lachia ◽  
Christian Gübeli ◽  
...  

Abstract Purpose Arbuscular mycorrhizal fungi (AMF) play important roles in agriculture because of their ability to improve plant resilience against abiotic and biotic stresses. AMF as a technology to promote a more sustainable agriculture holds great potential, yet many factors affect the efficiency of this plant-microbe symbiosis leading to inconsistency in performance. The beneficial symbiosis between plants and AM fungi, also-known-as the mycorrhiza is promoted by strigolactones (SLs), carotenoid derivatives active as phytohormones and rhizosphere signals. Natural SLs are effective at extremely low concentrations, however their bioavailability in soil is scarce because their biosynthesis and exudation are plant-regulated, their degradation is fast and their mobility in soil is limited. Methods Through a broad synthetic chemistry approach, we explored how structurally diverse SL derivatives could improve hyphal branching of Gigaspora spp AMF under laboratory conditions and thus possibly boost mycorrhization into soil. Results We tested twenty-six different derivatives and we could highlight structural enhancements to promote hyphal branching of in vitro germinated AMF spores at equal, and in some cases higher levels compared to natural SLs. A subset of these derivatives was tested for bioavailability, but no clear correlation was found with their activity on hyphal branching. Conclusion This study suggests that we could use a targeted, chemical-design approach to synthetize new SL derivatives to enable enhanced promotion of mycorrhization and potentially enhanced bioavailability compared to natural SLs. Due to the roles of AMF in crop production systems, these results highlight new innovative approaches to promote sustainable agriculture.


Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 583
Author(s):  
Reda E. Abdelhameed ◽  
Nagwa I. Abu-Elsaad ◽  
Arafat Abdel Hamed Abdel Latef ◽  
Rabab A. Metwally

Important gaps in knowledge remain regarding the potential of nanoparticles (NPs) for plants, particularly the existence of helpful microorganisms, for instance, arbuscular mycorrhizal (AM) fungi present in the soil. Hence, more profound studies are required to distinguish the impact of NPs on plant growth inoculated with AM fungi and their role in NP uptake to develop smart nanotechnology implementations in crop improvement. Zinc ferrite (ZnFe2O4) NPs are prepared via the citrate technique and defined by X-ray diffraction (XRD) as well as transmission electron microscopy for several physical properties. The analysis of the XRD pattern confirmed the creation of a nanocrystalline structure with a crystallite size equal to 25.4 nm. The effects of ZnFe2O4 NP on AM fungi, growth and pigment content as well as nutrient uptake of pea (Pisum sativum) plants were assessed. ZnFe2O4 NP application caused a slight decrease in root colonization. However, its application showed an augmentation of 74.36% and 91.89% in AM pea plant shoots and roots’ fresh weights, respectively, compared to the control. Moreover, the synthesized ZnFe2O4 NP uptake by plant roots and their contents were enhanced by AM fungi. These findings suggest the safe use of ZnFe2O4 NPs in nano-agricultural applications for plant development with AM fungi.


Author(s):  
Yinli Bi ◽  
Linlin Xie ◽  
Zhigang Wang ◽  
Kun Wang ◽  
Wenwen Liu ◽  
...  

AbstractArbuscular mycorrhizal (AM) fungi can successfully enhance photosynthesis (Pn) and plants growth in agricultural or grassland ecosystems. However, how the symbionts affect species restoration in sunlight-intensive areas remains largely unexplored. Therefore, this study’s objective was to assess the effect of AM fungi on apricot seedling physiology, within a specific time period, in northwest China. In 2010, an experimental field was established in Shaanxi Province, northwest China. The experimental treatments included two AM fungi inoculation levels (0 or 100 g of AM fungal inoculum per seedling), three shade levels (1900, 1100, and 550 µmol m−2 s−1), and three ages (1, 3, and 5 years) of transplantation. We examined growth, Pn, and morphological indicators of apricot (Prunus sibirica L.) seedling performances in 2011, 2013, and 2015. The colonization rate in mycorrhizal seedlings with similar amounts of shade is higher than the corresponding controls. The mycorrhizal seedling biomass is significantly higher than the corresponding non-mycorrhizal seedling biomass. Generally, Pn, stomatal conductance (Gs), transpiration rate (Tr), and water use efficiency are also significantly higher in the mycorrhizal seedlings. Moreover, mycorrhizal seedlings with light shade (LS) have the highest Pn. WUE is increased in non-mycorrhizal seedlings because of the reduction in Tr, while Tr is increased in mycorrhizal seedlings with shade. There is a significant increase in the N, P, and K fractions detected in roots compared with shoots. This means that LS had apparent benefits for mycorrhizal seedlings. Our results also indicate that AM fungi, combined with LS, exert a positive effect on apricot behavior.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Crosino ◽  
Elisa Moscato ◽  
Marco Blangetti ◽  
Gennaro Carotenuto ◽  
Federica Spina ◽  
...  

AbstractShort chain chitooligosaccharides (COs) are chitin derivative molecules involved in plant-fungus signaling during arbuscular mycorrhizal (AM) interactions. In host plants, COs activate a symbiotic signalling pathway that regulates AM-related gene expression. Furthermore, exogenous CO application was shown to promote AM establishment, with a major interest for agricultural applications of AM fungi as biofertilizers. Currently, the main source of commercial COs is from the shrimp processing industry, but purification costs and environmental concerns limit the convenience of this approach. In an attempt to find a low cost and low impact alternative, this work aimed to isolate, characterize and test the bioactivity of COs from selected strains of phylogenetically distant filamentous fungi: Pleurotus ostreatus, Cunninghamella bertholletiae and Trichoderma viride. Our optimized protocol successfully isolated short chain COs from lyophilized fungal biomass. Fungal COs were more acetylated and displayed a higher biological activity compared to shrimp-derived COs, a feature that—alongside low production costs—opens promising perspectives for the large scale use of COs in agriculture.


2021 ◽  
Vol 9 (2) ◽  
pp. 229
Author(s):  
Martti Vasar ◽  
John Davison ◽  
Siim-Kaarel Sepp ◽  
Maarja Öpik ◽  
Mari Moora ◽  
...  

Deserts cover a significant proportion of the Earth’s surface and continue to expand as a consequence of climate change. Mutualistic arbuscular mycorrhizal (AM) fungi are functionally important plant root symbionts, and may be particularly important in drought stressed systems such as deserts. Here we provide a first molecular characterization of the AM fungi occurring in several desert ecosystems worldwide. We sequenced AM fungal DNA from soil samples collected from deserts in six different regions of the globe using the primer pair WANDA-AML2 with Illumina MiSeq. We recorded altogether 50 AM fungal phylotypes. Glomeraceae was the most common family, while Claroideoglomeraceae, Diversisporaceae and Acaulosporaceae were represented with lower frequency and abundance. The most diverse site, with 35 virtual taxa (VT), was in the Israeli Negev desert. Sites representing harsh conditions yielded relatively few reads and low richness estimates, for example, a Saudi Arabian desert site where only three Diversispora VT were recorded. The AM fungal taxa recorded in the desert soils are mostly geographically and ecologically widespread. However, in four sites out of six, communities comprised more desert-affiliated taxa (according to the MaarjAM database) than expected at random. AM fungal VT present in samples were phylogenetically clustered compared with the global taxon pool, suggesting that nonrandom assembly processes, notably habitat filtering, may have shaped desert fungal assemblages.


2021 ◽  
Vol 22 (2) ◽  
pp. 711
Author(s):  
Irina V. Leppyanen ◽  
Olga A. Pavlova ◽  
Maria A. Vashurina ◽  
Andrey D. Bovin ◽  
Alexandra V. Dolgikh ◽  
...  

This study focused on the interactions of pea (Pisum sativum L.) plants with phytopathogenic and beneficial fungi. Here, we examined whether the lysin-motif (LysM) receptor-like kinase PsLYK9 is directly involved in the perception of long- and short-chain chitooligosaccharides (COs) released after hydrolysis of the cell walls of phytopathogenic fungi and identified in arbuscular mycorrhizal (AM) fungal exudates. The identification and analysis of pea mutants impaired in the lyk9 gene confirmed the involvement of PsLYK9 in symbiosis development with AM fungi. Additionally, PsLYK9 regulated the immune response and resistance to phytopathogenic fungi, suggesting its bifunctional role. The existence of co-receptors may provide explanations for the potential dual role of PsLYK9 in the regulation of interactions with pathogenic and AM fungi. Co-immunoprecipitation assay revealed that PsLYK9 and two proposed co-receptors, PsLYR4 and PsLYR3, can form complexes. Analysis of binding capacity showed that PsLYK9 and PsLYR4, synthesized as extracellular domains in insect cells, were able to bind the deacetylated (DA) oligomers CO5-DA–CO8-DA. Our results suggest that the receptor complex consisting of PsLYK9 and PsLYR4 can trigger a signal pathway that stimulates the immune response in peas. However, PsLYR3 seems not to be involved in the perception of CO4-5, as a possible co-receptor of PsLYK9.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manoj-Kumar Arthikala ◽  
Kalpana Nanjareddy ◽  
Lourdes Blanco ◽  
Xóchitl Alvarado-Affantranger ◽  
Miguel Lara

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Christopher Ngosong ◽  
Elke Gabriel ◽  
Liliane Ruess

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.


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