Faculty Opinions recommendation of The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis.

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.

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The Diversity of Root-Associated Endophytic Fungi from Four Epiphytic Orchids in China

Diversity ◽

10.3390/d13050197 ◽

2021 ◽

Vol 13 (5) ◽

pp. 197

Author(s):

Tao Wang ◽

Miao Chi ◽

Ling Guo ◽

Donghuan Liu ◽

Yu Yang ◽

...

Keyword(s):

Endophytic Fungi ◽

Southern China ◽

Culture Method ◽

Amplicon Sequencing ◽

Community Diversity ◽

Mycorrhizal Symbiosis ◽

Epiphytic Orchids ◽

Culture Independent ◽

Almost All

Root-associated endophytic fungi (RAF) are found asymptomatically in almost all plant groups. However, little is known about the compositions and potential functions of RAF communities associated with most Orchidaceae species. In this study, the diversity of RAF was examined in four wild epiphytic orchids, Acampe rigida, Doritis pulcherrima, Renanthera coccinea, and Robiquetia succisa, that occur in southern China. A culture-independent method involving Illumina amplicon sequencing, and an in vitro culture method, were used to identify culturable fungi. The RAF community diversity differed among the orchid roots, and some fungal taxa were clearly concentrated in a certain orchid species, with more OTUs being detected. By investigating mycorrhizal associations, the results showed that 28 (about 0.8%) of the 3527 operational taxonomic units (OTUs) could be assigned as OMF, while the OTUs of non-mycorrhizal fungal were about 99.2%. Among the OMFs, Ceratobasidiaceae OTUs were the most abundant with different richness, followed by Thelephoraceae. In addition, five Ceratobasidium sp. strains were isolated from D. pulcherrima, R. succisa, and R. coccinea roots with high separation rates. These culturable Ceratobasidium strains will provide materials for host orchid conservation and for studying the mechanisms underlying mycorrhizal symbiosis.

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Extraction of short chain chitooligosaccharides from fungal biomass and their use as promoters of arbuscular mycorrhizal symbiosis

Scientific Reports ◽

10.1038/s41598-021-83299-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Andrea Crosino ◽

Elisa Moscato ◽

Marco Blangetti ◽

Gennaro Carotenuto ◽

Federica Spina ◽

...

Keyword(s):

Fungal Biomass ◽

Large Scale ◽

Low Cost ◽

Trichoderma Viride ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Production Costs ◽

Short Chain ◽

Mycorrhizal Symbiosis ◽

Major Interest

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.

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Conditioning plants for arbuscular mycorrhizal symbiosis through DWARF14-LIKE signalling

Current Opinion in Plant Biology ◽

10.1016/j.pbi.2021.102071 ◽

2021 ◽

Vol 62 ◽

pp. 102071

Author(s):

Raphaella Hull ◽

Jeongmin Choi ◽

Uta Paszkowski

Keyword(s):

Arbuscular Mycorrhizal ◽

Arbuscular Mycorrhizal Symbiosis ◽

Mycorrhizal Symbiosis

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Metabolomics and transcriptomics to decipher molecular mechanisms underlying ectomycorrhizal root colonization of an oak tree

Scientific Reports ◽

10.1038/s41598-021-87886-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

M. Sebastiana ◽

A. Gargallo-Garriga ◽

J. Sardans ◽

M. Pérez-Trujillo ◽

F. Monteiro ◽

...

Keyword(s):

Molecular Mechanisms ◽

Positive Impact ◽

Ectomycorrhizal Fungus ◽

Cork Oak ◽

Mycorrhizal Symbiosis ◽

Gamma Aminobutyric Acid ◽

Ectomycorrhizal Symbiosis ◽

Ectomycorrhizal Roots ◽

Oak Tree ◽

Mycorrhizal Roots

AbstractMycorrhizas are known to have a positive impact on plant growth and ability to resist major biotic and abiotic stresses. However, the metabolic alterations underlying mycorrhizal symbiosis are still understudied. By using metabolomics and transcriptomics approaches, cork oak roots colonized by the ectomycorrhizal fungus Pisolithus tinctorius were compared with non-colonized roots. Results show that compounds putatively corresponding to carbohydrates, organic acids, tannins, long-chain fatty acids and monoacylglycerols, were depleted in ectomycorrhizal cork oak colonized roots. Conversely, non-proteogenic amino acids, such as gamma-aminobutyric acid (GABA), and several putative defense-related compounds, including oxylipin-family compounds, terpenoids and B6 vitamers were induced in mycorrhizal roots. Transcriptomic analysis suggests the involvement of GABA in ectomycorrhizal symbiosis through increased synthesis and inhibition of degradation in mycorrhizal roots. Results from this global metabolomics analysis suggest decreases in root metabolites which are common components of exudates, and in compounds related to root external protective layers which could facilitate plant-fungal contact and enhance symbiosis. Root metabolic pathways involved in defense against stress were induced in ectomycorrhizal roots that could be involved in a plant mechanism to avoid uncontrolled growth of the fungal symbiont in the root apoplast. Several of the identified symbiosis-specific metabolites, such as GABA, may help to understand how ectomycorrhizal fungi such as P. tinctorius benefit their host plants.

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