scholarly journals Structure-specific regulation of nutrient absorption, metabolism and transfer in arbuscular mycorrhizal fungi

2018 ◽  
Author(s):  
Hiromu Kameoka ◽  
Taro Maeda ◽  
Nao Okuma ◽  
Masayoshi Kawaguchi

AbstractArbuscular mycorrhizal fungi (AMF) establish symbiotic relationships with most land plants, mainly for the purpose of nutrient exchange. Many studies have revealed the regulation of absorption, metabolism, and transfer of nutrients in AMF and the genes involved in these processes. However, the spatial regulation of the genes among the structures comprising each developmental stage are not well understood. Here, we demonstrate the structure-specific transcriptome of the model AMF species, Rhizophagus irregularis. We performed an ultra-low input RNA-seq analysis, SMART-seq2, comparing five extraradical structures, germ tubes, runner hyphae, branched absorbing structures, immature spores, and mature spores. In addition, we reanalyzed the recently reported RNA-seq data comparing intraradical hyphae and arbuscules. Our analyses captured the distinct features of each structure and revealed the structure-specific expression patterns of genes related to absorption, metabolism, and transfer of nutrients. Of note, the transcriptional profiles suggest the distinct functions of branched absorbing structures in nutrient absorption. These findings provide a comprehensive dataset to advance our understanding of the transcriptional dynamics of fungal nutrition in this symbiotic system.

2019 ◽  
Vol 60 (10) ◽  
pp. 2272-2281 ◽  
Author(s):  
Hiromu Kameoka ◽  
Taro Maeda ◽  
Nao Okuma ◽  
Masayoshi Kawaguchi

Abstract Arbuscular mycorrhizal fungi (AMF) establish symbiotic relationships with most land plants, mainly for the purpose of nutrient exchange. Many studies have revealed the regulation of processes in AMF, such as nutrient absorption from soil, metabolism and exchange with host plants, and the genes involved. However, the spatial regulation of the genes within the structures comprising each developmental stage is not well understood. Here, we demonstrate the structure-specific transcriptome of the model AMF species, Rhizophagus irregularis. We performed an ultra-low input RNA-seq analysis, SMART-seq2, comparing five extraradical structures, germ tubes, runner hyphae, branched absorbing structures (BAS), immature spores and mature spores. In addition, we reanalyzed the recently reported RNA-seq data comparing intraradical mycelium and arbuscule. Our analyses captured the distinct features of each structure and revealed the structure-specific expression patterns of genes related to nutrient transport and metabolism. Of note, the transcriptional profiles suggest distinct functions of BAS in nutrient absorption. These findings provide a comprehensive dataset to advance our understanding of the transcriptional dynamics of fungal nutrition in this symbiotic system.


Author(s):  
Bo Shu ◽  
YaChao Xie ◽  
Fei Zhang ◽  
Dejian Zhang ◽  
Chunyan Liu ◽  
...  

Calmodulin-like (CML) proteins represent a diverse family of protein in plants, and play significant roles in biotic and abiotic stress responses. However, the involvement of citrus CMLs in plant responses to drought stress (abiotic stress) and arbuscular mycorrhizal fungi (AMF) colonization remain relatively unknown. We characterized the citrus CML genes by analyzing the EF-hand domains and a genome-wide search, and identified a total of 38 such genes, distributed across at least nine chromosomes. Six tandem duplication clusters were observed in the CsCMLs, and 12 CsCMLs exhibited syntenic relationships with Arabidopsis thaliana CMLs. Gene expression analysis showed that 29 CsCMLs were expressed in the roots, and exhibited differential expression patterns. The regulation of CsCMLs expression was not consistent with the cis-elements identified in their promoters. CsCML2, 3, and 5 were upregulated in response to drought stress, and AMF colonization repressed the expression of CsCML7, 9, 12, 13,20, 27, 28, and 35,and induced that of CsCML1, 2, 3, 5, 8, 10, 11, 14, 15, 16, 18, 25, 30, 33, and 37. Furthermore, AMF colonization and drought stress exerted a synergistic effect, evident from the enhanced repression of CsCML7, 9, 12, 13, 27, 28, and 35 and enhanced expression of CsCML2, 3, and 5 under AMF colonization and drought stress. The present study provides valuable insights into the CsCML gene family and its responses to AMF colonization and drought stress.


2015 ◽  
Vol 28 (4) ◽  
pp. 408-419 ◽  
Author(s):  
Zhilei Liu ◽  
Yuanjing Li ◽  
Lina Ma ◽  
Haichao Wei ◽  
Jianfeng Zhang ◽  
...  

Mitogen-activated protein kinase (MAPK) cascades play important roles in the stress response in both plants and microorganisms. The mycorrhizal symbiosis established between arbuscular mycorrhizal fungi (AMF) and plants can enhance plant drought tolerance, which might be closely related to the fungal MAPK response and the molecular dialogue between fungal and soybean MAPK cascades. To verify the above hypothesis, germinal Glomus intraradices (syn. Rhizophagus irregularis) spores and potted experiments were conducted. The results showed that AMF GiMAPKs with high homology with MAPKs from Saccharomyces cerevisiae had different gene expression patterns under different conditions (nitrogen starvation, abscisic acid treatment, and drought). Drought stress upregulated the levels of fungi and soybean MAPK transcripts in mycorrhizal soybean roots, indicating the possibility of a molecular dialogue between the two symbiotic sides of symbiosis and suggesting that they might cooperate to regulate the mycorrhizal soybean drought-stress response. Meanwhile, the changes in hydrogen peroxide, soluble sugar, and proline levels in mycorrhizal soybean as well as in the accelerated exchange of carbon and nitrogen in the symbionts were contributable to drought adaptation of the host plants. Thus, it can be preliminarily inferred that the interactions of MAPK signals on both sides, symbiotic fungus and plant, might regulate the response of symbiosis and, thus, improve the resistance of mycorrhizal soybean to drought stress.


Author(s):  
Arpitha Shankar

AMF (Arbuscular Mychorhizal Fungi) are very well known due to their importance in promoting growth and developments of plants especially vegetables. These fungi can be grown easily, stored and multiplied with simple means, also the application of these fungi is generally on the layer of the soil or near the roots in the inner layers of the soils. The growth of the amf fungi is very easy and they are highly adjustable to any soil and environmental conditions. In this review our main focus is on the use of amf for production of vegetables and also the effect of amf against insects and pests. The amf is known to reduce several symptoms caused by different insect pests and also plant diseases thereby promoting healthy growth of the plants. Also use of this amf will increase the uptake of nutrient from the soils through symbiotic relationships between plants and fungi. The uptake of important minerals which are drawn from deeper layers of soils is observed with the help pf amf. This study reveals the benefits of the use of amf under severe disease and pest incidences thereby known as an alternate for harmful chemical pesticides and fungicides.


2021 ◽  
Author(s):  
Zhifang Ran ◽  
Xiaotong Yang ◽  
Yongqing Zhang ◽  
Jie Zhou

Abstract Panax quinquefolius L. has been considered as an important traditional Chinese medicine with a history of more than 300 years in China. Ginsenoside is the main bioactive component. Our research group has found that the accumulation of ginsenoside could be affected by arbuscular mycorrhizal fungi (AMF). However the underlying mechanism how AMF affected the biosynthesis of ginsenoside in P. quinquefolius is still unclear. In this study, the RNA-seq analysis was used to evaluate the effects of AMF (Rhizophagus intraradices, R. intraradices) on the expression of ginsenoside synthesis related genes in P. quinquefolius root. The results indicated that a symbiotic relationship between R. intraradices and P. quinquefolius was established. RNA-seq achieved approximately 48.62 G reads of all samples. Assembly of all the reads involved in all samples produced 63420 transcripts and 24137 unigenes. Differential expression analysis was performed between the control and AMF group. A total of 111 differentially expressed genes (DEGs) in response to AMF vs control were identified, 78 and 33 transcripts were upregulated and downregulated, respectively. Based on the functional analysis, Gene ontology (GO) analysis revealed that most DEGs were related to stress responses and cellular metabolic processes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified transduction, plant hormone signal transduction and terpenoids and polyketides biosynthesis pathways. Furthermore, the expression of glycolysis-related genes and ginsenoside synthesis related genes was largely induced by AMF. In conclusion, our results comprehensively elucidated the molecular mechanism how AMF affected the biosynthesis of ginsenoside in P.quinquefolius by transcriptome profiling.


2021 ◽  
Author(s):  
Jing Tao ◽  
Fengxin Dong ◽  
Yihan Wang ◽  
Hui Chen ◽  
Ming Tang

Abstract Background: Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with host plants, which can promote plants to absorb more water and nutrients, and thus improve the stress resistance of plants. Our study aimed to investigate the effects of Rhizophagus irregularis on Populus simonii × P. nigra seedlings under drought stress. Results: The experiment was a completely random design with two water conditions (well-watered or drought stress) and two AMF treatments (inoculated with or without R. irregularis). Our results showed that mycorrhizal seedlings performed less oxidative damage and stronger tolerance of drought, which recorded higher photosynthesis and less concentrations of Malondialdehyde (MDA), H2O2, and proline under drought stress versus non-mycorrhizal seedlings. Under drought stress, AMF inoculation reduced soluble sugar concentration in leaves but promoted its accumulation in roots. The superoxide dismutase (SOD) activity in leaves and roots, and catalase (CAT) activity in roots of mycorrhizal seedlings were lower than non-mycorrhizal seedlings, but CAT activity in leaves of mycorrhizal seedlings was higher than non-mycorrhizal seedlings under drought stress. Drought stress and AMF inoculation both induced the expressions of MAPKs of P. simonii × P. nigra, but the expression patterns of MAPKs under four treatments were obviously different.Conclusions: Overall, our results demonstrated that mycorrhizal seedlings had less oxidative damage and stronger tolerance to drought. MAPKs expressions of P. simonii×P. nigra (PsnMAPKs) were induced by drought stress and AMF inoculation, and the expression patterns of PsnMAPKs in response to drought stress were different between mycorrhizal and non-mycorrhizal seedlings. Non-mycorrhizal seedlings may be adapted to drought by up-regulating MAPKs expressions leading to stomatal closure. Drought stress decreased serval PsnMAPKs expressions induced by AMF inoculation, which may be associated with mycorrhizal colonization.


Author(s):  
Abdoulaye Fofana Fall ◽  
Grace Nakabonge ◽  
Joseph Ssekandi ◽  
Hassna Founoune-Mboup ◽  
Samuel Obeng Apori ◽  
...  

A single paragraph Arbuscular mycorrhizal fungi (AMF) establish symbiotic relationships with many crops. These soil microbiotas improve the soil fertility through the soil physical, chemical and biological properties. extending the root absorbing area. In return, the symbiont receives plant carbohydrates for the completion of its life cycle. AMF also helps plants to cope with biotic and abiotic stresses such as extreme temperature, heavy metal, diseases, and pathogens. For soil physical properties, the mechanisms used by AMF are the production of a glycoprotein, glomalin, which creates a high quality of soil macro-aggregations. These macro-aggregations control soil erosion, nutrients and organic matter losses. For soil chemical properties, AMF produce acids and an enzyme called phosphatase. This enzyme hydrolyzes the inorganic phosphorus and the rock phosphate (RP) hence making P available in the soil for plant uptake. AMF also are involved in soil nitrogen, carbon and trace element cycling. Regarding the biological component of the soil, AMF influence the composition, diversity and activity of microbial communities in the hydrosphere. They also work in synergy with others soil microorganisms to improve soil fertility, plant growth and resistance against some diseases. In this review, we present the contribution of AMF on soil fertility and importance in polluted soils.


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