Fungal Plant Research Articles

Nitrogen deposition strengthens the relationship between plants and the soil fungal community in alpine steppe, North Tibet

The response of the relationship between plants and microbes to nitrogen (N) deposition has attracted considerable attention in the research community; however, results on how N deposition affects the relationship between plants and bacteria, fungi, or both, are inconsistent. In the present study, we estimated how the relationship between plants and the soil microbial community was affected by N deposition in a 5-year N addition experiment at an alpine steppe site in North Tibet. Nitrogen addition not only improved shoot biomass, the litter of shoot biomass, and root biomass, but also changed the composition of the plant community from one dominated by perennial forbs to perennial bunch-grasses. We found significant changes in the soil fungal community, but not in the soil bacterial community. Structural equation modeling revealed that N addition directly influenced the plant community, but not the soil microbial community. The changes in plant composition and biomass revealed that the plant community directly strengthened the abundance of soil fungi and altered its community composition, which is contrary to other research results. Therefore, our findings indicate up-regulating effects of high N availability on plant–fungi interactions in alpine steppe, which may strengthen the relationship between the plant and fungal communities and alter the ecosystem's functions and services.

Antifungal activity and resistance induction against Sclerotium cepivorum by plant growth-promoting fungi in onion plants

The influence of the inoculation with plant growth-promoting fungi (PGPF) isolates on growth enhancement of onion plants and progress of white rot disease in onions, caused by Sclerotium cepivorum, was evaluated. The tested PGPF isolates were Phoma sp. GS8-1, Phoma sp. GS 8-3, Trichoderma asperellum SKT-1, Fusarium equiseti GF18-3 and Penicillium simplicissmum GP17-2. Abnormal shape and lysis in the mycelia of the pathogen were reported in dual cultures of PGPF and S. cepivorum using scanning electron microscopy. The germination of sclerotia was reduced after soaking in culture filtrates of PGPF. The highest reduction was recorded in P. simplicissmum GP17-2 treatment (70.85%). The results demonstrated that the treatments with PGPF isolates significantly enhanced the plant height, root length, bulb perimeter and plant dry weight. Additionally, PGPF clearly reduced disease severity of white rot disease of onions. Among PGPF isolates, T. asperellum SKT-1 and P. simplicissmum GP17-2 showed the best effects in reducing the incidence and severity of white rot and enhancing onion growth. On the other hand, the levels of peroxidase and polyphenol oxidase were improved in the treated onion plants than in the untreated plants at 7 days after induction treatments. Similarly, early and strong expressions of defence genes, PR1 and PR2, were reported in plants treated with PGPF. Overall, this research suggested that PGPF treatments generated favourable effects on the suppression of white rot disease of onions.

FpDep1, a component of Rpd3L histone deacetylase complex, is important for vegetative development, ROS accumulation, and pathogenesis in Fusarium pseudograminearum

Histone deacetylases (HDACs) play essential roles in modulating chromatin structure to provide accessibility to gene regulators. Increasing evidence has linked HADCs to pathogenesis control in the filamentous plant fungi. However, its function remains unclear in Fusarium pseudograminearum, which has led to the emergence of the disease Fusarium crown rot in China. Here we identified the FpDEP1 gene, an orthologue of Saccharomyces cerevisiae DEP1 encoding a component of the Rpd3 histone deacetylase complex in F. pseudograminearum. The gene deletion mutant, ΔFpdep1, showed significantly retarded growth on PDA plates with reduced aerial hyphae formation. Pathogenicity tests displayed no typical leaf lesions and limited expansion capability of coleoptiles. Histopathological analysis indicated the ΔFpdep1 deletion mutant differentiated infectious hyphae and triggered massive reactive oxygen species (ROS) accumulation during the early infection stage, resulting in limited expansion to neighbor cells which was concurring with sensitivity to H2O2 and SDS tests in vitro. FM4-64 staining revealed that the ΔFpdep1 deletion mutant was delayed in endocytosis. The FpDEP1-GFP transgene complemented the mutant phenotypes and the fusion protein co-localized with DAPI staining, indicating that the FpDEP1 gene product is localized to the nucleus in spores and mycelia. Immunoprecipitation coupled with LC-MS/MS and yeast two-hybrid screening identified the Rpd3L-like HDAC complex containing at least FpDep1, FpSds3, FpSin3, FpRpd3, FpRxt3, FpCti6, FpRho23, and FpUme6. These results suggest that FpDep1 is involved in a HDAC complex functioning on fungal development and pathogenesis in F. pseudograminearum.

Analysis Of The Corticium Salmonicolor Mushroom That Grows On Rubber, Citrus And Coffee Plants Uses Fuzzy Methods

Indonesia is an agrarian country and makes agriculture as one of the economic sectors, rubber, oranges and coffee farming plants are many cultivated commodities. One of the problems in the agricultural sector today is the prevention of pests and diseases. Cortikium salmonicolor fungus is one of the many diseases that harm farmers, corticum mushroom salmonicolor is a disease that causes the death of twigs, stems and roots of plants. By applying fuzzy methods, the design rules are made that can detect corticium salmonicolor fungi in plants, rubber, oranges and coffee, which have three inputs and one output. Each object was analyzed with the same treatment so that three indicators were found in determining the detection of the corticium salmonicolor fungus. Fuzzy logic is defined as a multilevel logic that provides intermediaries the value to be determined between conventional evaluations such as right or wrong, yes or no, high or low, and so on. As a result, this rule is used to detect salmonium corticium fungi. This research can be developed by creating expert systems and screening tools.

Interrelations between Alien and Native Foliar Fungal Pathogens and Woody Plants in Siberia

This article presents the results of 15-year observations of alien and native foliar fungal pathogens and woody plants in Siberian arboreta and urban ecosystems and discusses the possibility of using these data to determine how the pathogenic mycobiota of woody species was formed under Siberian conditions. In total, 121 species of pathogenic micromycetes affecting the leaves of woody plants in botanical gardens and city and belonging to 2 divisions, 14 orders, and 46 genera have been revealed. Most of these species belong to the Ascomycota division (86.8%). The Basidiomycota division is represented by fungi from the order Pucciniales. Among all observed pathogens, 21 species belong to powdery mildew fungi, 15 species belong to rust fungi, and 84 species represent anamorphic fungi. A study of 108 woody plant species growing in Siberian cities has revealed 101 species of leaf pathogens, while 158 woody plant species growing in arboreta have been inhabited by 105 pathogen species. All fungal species revealed during this study, except for three species (Mycopappus alni, Venturia acerina, and Phyllosticta westendorpii), have been observed in Siberia earlier. However, some fungus–host plant associations are apparently new to science, suggesting that complexes of cryptic species differing in their host range and geographic range may occur. The main sources for tree mycobiota formation in Siberia include the invasion of pathogens together with alien plant species, the transition of pathogens from native to alien plant species, the enhancement of a pathogenicity of saprotrophic fungi, and the expansion of fungi onto new hosts. The majority of pathogens (65−75% of the total number of revealed fungi) locate on native plants. Alien plants are infected mainly by (native) pathogens. Only eight pathogen species have been introduced in Siberia with alien plants; three of them originate from the Far East (Cercospora gotoana, Phyllosticta phellodendricola, and Erysiphe palczewskii), while five are of European origin (Cladosporium syringae, Phyllosticta vincae-minoris, Erysiphe syringae, Erysiphe alphitoides, and Erysiphe berberidis). In Siberia, the lateness of phenological phases of plants originating from mild climatic zones, may be favorable for the development of fungal pathogens, such as Erysiphe alphitoides, causing the powdery mildew of oak trees.

Evolution and networks in ancient and widespread symbioses between Mucoromycotina and liverworts

Like the majority of land plants, liverworts regularly form intimate symbioses with arbuscular mycorrhizal fungi (Glomeromycotina). Recent phylogenetic and physiological studies report that they also form intimate symbioses with Mucoromycotina fungi and that some of these, like those involving Glomeromycotina, represent nutritional mutualisms. To compare these symbioses, we carried out a global analysis of Mucoromycotina fungi in liverworts and other plants using species delimitation, ancestral reconstruction, and network analyses. We found that Mucoromycotina are more common and diverse symbionts of liverworts than previously thought, globally distributed, ancestral, and often co-occur with Glomeromycotina within plants. However, our results also suggest that the associations formed by Mucoromycotina fungi are fundamentally different because, unlike Glomeromycotina, they may have evolved multiple times and their symbiotic networks are un-nested (i.e., not forming nested subsets of species). We infer that the global Mucoromycotina symbiosis is evolutionarily and ecologically distinctive.

Greener synthesis of chemical compounds and materials.

Modern trends in the greener synthesis and fabrication of inorganic, organic and coordination compounds, materials, nanomaterials, hybrids and nanocomposites are discussed. Green chemistry deals with synthesis procedures according to its classic 12 principles, contributing to the sustainability of chemical processes, energy savings, lesser toxicity of reagents and final products, lesser damage to the environment and human health, decreasing the risk of global overheating, and more rational use of natural resources and agricultural wastes. Greener techniques have been applied to synthesize both well-known chemical compounds by more sustainable routes and completely new materials. A range of nanosized materials and composites can be produced by greener routes, including nanoparticles of metals, non-metals, their oxides and salts, aerogels or quantum dots. At the same time, such classic materials as cement, ceramics, adsorbents, polymers, bioplastics and biocomposites can be improved or obtained by cleaner processes. Several non-contaminating physical methods, such as microwave heating, ultrasound-assisted and hydrothermal processes or ball milling, frequently in combination with the use of natural precursors, are of major importance in the greener synthesis, as well as solventless and biosynthesis techniques. Non-hazardous solvents including ionic liquids, use of plant extracts, fungi, yeasts, bacteria and viruses are also discussed in relation with materials fabrication. Availability, necessity and profitability of scaling up green processes are discussed.

Genetic evidence for Magnaporthe oryzae vitamin B3 acquisition from rice cells.

Following penetration, the devastating rice blast fungus Magnaporthe oryzae, like some other important eukaryotic phytopathogens, grows in intimate contact with living plant cells before causing disease. Cell-to-cell growth during this biotrophic growth stage must involve nutrient acquisition, but experimental evidence for the internalization and metabolism of host-derived compounds is exceedingly sparse. This striking gap in our knowledge of the infection process undermines accurate conceptualization of the plant-fungal interaction. Here, through our general interest in Magnaporthe metabolism and with a specific focus on the signalling and redox cofactor nicotinamide adenine dinucleotide (NAD), we deleted the M. oryzae QPT1 gene encoding quinolinate phosphoribosyltransferase, catalyst of the last step in de novo NAD biosynthesis from tryptophan. We show how QPT1 is essential for axenic growth on minimal media lacking nicotinic acid (NA, an importable NAD precursor). However, Δqpt1 mutant strains were fully pathogenic, indicating de novo NAD biosynthesis is dispensable for lesion expansion following invasive hyphal growth in leaf tissue. Because overcoming the loss of de novo NAD biosynthesis in planta can only occur if importable NAD precursors (which solely comprise the NA, nicotinamide and nicotinamide riboside forms of vitamin B3) are accessible, we unexpectedly but unequivocally demonstrate that vitamin B3 can be acquired from the host and assimilated into Magnaporthe metabolism during growth in rice cells. Our results furnish a rare, experimentally determined example of host nutrient acquisition by a fungal plant pathogen and are significant in expanding our knowledge of events at the plant-fungus metabolic interface.

Fungal-Induced Formation of Auxin Maxima in Arabidopsis thaliana Roots

Phytohormones are crucial molecules for plant development and the interaction with microbes. This study focused on the phytohormone auxin (indole-3-acetic acid, IAA) and its role in the interaction of Arabidopsis thaliana (L.) Heynh. roots with two beneficial (Piriformospora indica and Mortierella hyalina) and two pathogenic (Alternaria brassicicola and Verticillium dahliae) root-colonizing fungi. Arabidopsis plants expressing the dual reporter construct DR5::EGFP-DR5v2::tdTomato allow visualization of auxin maxima during early stages of the plant–fungus interaction. Fluorescence microscopy was used to monitor changes in auxin levels and distribution patterns. We hereby demonstrate that only the beneficial P. indica activates the IAA reporter system. M. hyalina- but not P. indica-colonized roots accumulate jasmonates which might prevent the activation of the IAA reporter system. Additionally, both the necrotrophic fungus A. brassicicola and the biotrophic fungus V. dahliae completely inhibit the fluorescence emission from the IAA reporter system within 3–6 h. The results indicate that the reporter system responds to IAA accumulation in symbiotic roots, but the activation process might be controlled by a crosstalk with other phytohormones, such as jasmonates.

Effectiveness of Green Synthesized Silver Nanoparticles (Ag-Nps) of Delonix Regia Pods in Water Disinfection

Particles of sizes between 1 and 100 nanometers are known as nanoparticles. The natural materials like plant leaf extract, bacteria and fungi for the synthesis of silver nanoparticles has numerous benefits. In this scenario, the main objective of this work is to utilize Delonix Regia pod extract for the synthesis of silver nanoparticles (NPs) and check its feasibility as disinfectant. Pod extract prepared was subjected to EDS analysis. Transformed silver NPs are coated onto GAC(1.5mm) and subjected to SEM analyses. Column study was carried to check the disinfecting action of silver NPs for varied contact time by monitoring MPN value. From this research work, it can be concluded as, for pod extract, peak absorbance was found at 360nm. Delonix Regia pod extract transforms into silver nanoparticles moderately to about 4.63-8.85%. Silver nanoparticles are coated onto Activated Carbon, dried and stored for extended period without loss of nanoparticles. At 30min contact time efficiency was found to be 63% and 71 for NP2.5 and NP5 respectively. Green synthesized silver nanoparticles are proved to be moderately effective in disinfecting contaminated water.

Evaluation of the Abundance of Fungi in Wastewater Treatment Plants Using Quantitative PCR (qPCR).

Assessment of the abundance of fungi in environmental samples by quantitative PCR (qPCR) of community DNA is often a difficult task due to biases introduced during PCR amplification, resulting from the differences associated with length polymorphism and the varying number of copies of the rRNA operon among fungal species, the lack of specificity of the primers targeting the different regions of the rRNA operon, or their insufficient coverage of the fungal lineages. To overcome those limitations, it is crucial to test and select the specific primers sets which provide the more accurate approximation to the quantification of the targeted fungal populations in a given set of samples. Fungi are a significant fraction of the microbiota in wastewater treatment plants (WWTPs), but the activated sludge microbial communities comprise many other eukaryotic microorganisms whose molecular markers are often coamplified by primers initially designed as fungal-specific. Here, the use of the FungiQuant primer set is recommended for the quantification of fungal molecular markers (18S rRNA genes) by qPCR in activated sludge samples and the full protocol is described.

Rice Husk Ash as an Adsorbent for Isolated the Celephthalides Compounds from Root of Apium Graveolens Linn for Inhibited Phytopathogenic Fungi in Plants

Rice Husk Ash as an Adsorbent for Isolated the Celephthalides Compounds from Root of Apium Graveolens Linn for Inhibited Phytopathogenic Fungi in Plants

Isolation of Natural Fungal Pathogens from Marchantia polymorpha Reveals Antagonism between Salicylic Acid and Jasmonate during Liverwort-Fungus Interactions.

The evolution of adaptive interactions with beneficial, neutral and detrimental microbes was one of the key features enabling plant terrestrialization. Extensive studies have revealed conserved and unique molecular mechanisms underlying plant-microbe interactions across different plant species; however, most insights gleaned to date have been limited to seed plants. The liverwort Marchantia polymorpha, a descendant of early diverging land plants, is gaining in popularity as an advantageous model system to understand land plant evolution. However, studying evolutionary molecular plant-microbe interactions in this model is hampered by the small number of pathogens known to infect M. polymorpha. Here, we describe four pathogenic fungal strains, Irpex lacteus Marchantia-infectious (MI)1, Phaeophlebiopsis peniophoroides MI2, Bjerkandera adusta MI3 and B. adusta MI4, isolated from diseased M. polymorpha. We demonstrate that salicylic acid (SA) treatment of M. polymorpha promotes infection of the I. lacteus MI1 that is likely to adopt a necrotrophic lifestyle, while this effect is suppressed by co-treatment with the bioactive jasmonate in M. polymorpha, dinor-cis-12-oxo-phytodienoic acid (dn-OPDA), suggesting that antagonistic interactions between SA and oxylipin pathways during plant-fungus interactions are ancient and were established already in liverworts.

Active Fungal Communities in Asymptomatic Eucalyptus grandis Stems Differ between a Susceptible and Resistant Clone.

Fungi represent a common and diverse part of the microbial communities that associate with plants. They also commonly colonise various plant parts asymptomatically. The molecular mechanisms of these interactions are, however, poorly understood. In this study we use transcriptomic data from Eucalyptus grandis, to demonstrate that RNA-seq data are a neglected source of information to study fungal–host interactions, by exploring the fungal transcripts they inevitably contain. We identified fungal transcripts from E. grandis data based on their sequence dissimilarity to the E. grandis genome and predicted biological functions. Taxonomic classifications identified, amongst other fungi, many well-known pathogenic fungal taxa in the asymptomatic tissue of E. grandis. The comparison of a clone of E. grandis resistant to Chrysoporthe austroafricana with a susceptible clone revealed a significant difference in the number of fungal transcripts, while the number of fungal taxa was not substantially affected. Classifications of transcripts based on their respective biological functions showed that the fungal communities of the two E. grandis clones associate with fundamental biological processes, with some notable differences. To shield the greater host defence machinery in the resistant E. grandis clone, fungi produce more secondary metabolites, whereas the environment for fungi associated with the susceptible E. grandis clone is more conducive for building fungal cellular structures and biomass growth. Secreted proteins included carbohydrate active enzymes that potentially are involved in fungal–plant and fungal–microbe interactions. While plant transcriptome datasets cannot replace the need for designed experiments to probe plant–microbe interactions at a molecular level, they clearly hold potential to add to the understanding of the diversity of plant–microbe interactions.

Design, synthesis and antifungal activity evaluation of isocryptolepine derivatives

In this paper, the nitrogen atom was inserted into the anthracycline system of the isocryptolepine nucleus to obtain the “Aza”-type structure benzo[4,5]imidazo[1,2-c] quinazoline. A series of “Aza”-type derivatives were designed, synthesized and evaluated for their antifungal activity against six plant fungi in vitro. Among all derivatives, compounds A-0, B-1 and B-2 showed significant antifungal activity against B. cinerea with the EC50 values of 2.72 μg/mL, 5.90 μg/mL and 4.00 μg/mL, respectively. Compound A-2 had the highest activity against M. oryzae with the EC50 values of 8.81 μg/mL, and compound A-1 demonstrated the most control efficacy against R. solani (EC50, 6.27 μg/mL). Moreover, compound A-0 was selected to investigate the in vivo tests against B. cinerea and the results indicated that the preventative efficacy of it up to 72.80% at 100 μg/mL. Preliminary mechanism studies revealed that after treatment with A-0 at 5 µg/mL, the B. cinerea mycelia appeared curved, collapsed and the cell membrane integrity may be damaged. The reactive oxygen species production, mitochondrial membrane potential and nuclear morphometry of mycelia have been changed, and the membrane function and cell proliferation of mycelia were destroyed. Compounds A-0, A-1, B-1 and B-2 presented weaker toxicities against two cells lines than isocryptolepine. This study lays the foundation for the future development of isocryptolepine derivatives as environmentally friendly and safe agricultural fungicides.

Threonine synthase CoTHR4 is involved in infection-related morphogenesis during the pre-penetration stage in Colletotrichum orbiculare

Upon recognition of host plants, Colletotrichum orbiculare, an anthracnose disease fungus of cucurbitaceous plants, initiates morphological differentiation, including conidial germination and appressorium formation on the cuticle layer. The series of infection processes of C. orbiculare requires enormous nutrient and energy, but the surface of the cucurbitaceous hosts is hardly nutrient-rich. Hence, C. orbiculare must exert tight management of its intracellular nutrients in order to properly induce infection-related morphogenesis. Here, we carried out a large-scale insertional mutagenesis screen using Agrobacterium tumefaciens-mediated transformation to identify novel genes involved in the pathogenicity of C. orbiculare and found that CoTHR4-encoded threonine synthase, a homolog of Saccharomyces cerevisiae THR4, is required for pathogenicity and conidiation in C. orbiculare. Threonine supplementation allowed the cothr4 mutant to produce conidia to a level equivalent to that of the wild-type. The conidia produced from the threonine-treated cothr4 mutant failed to germinate in the absence of threonine, but retained the ability to germinate and to form appressoria in the presence of threonine. However, the conidia produced from the threonine-treated cothr4 mutant remained attenuated in pathogenicity on cucumber cotyledons even in the presence of threonine. Cytorrhysis assays revealed that appressoria of the cothr4 mutant induced by exogenous threonine treatment showed low turgor generation. Taken together, these results showed that threonine synthase CoThr4 plays a pivotal role in infection-related morphogenesis during the pre-penetration stage of C. orbiculare.

Identification of Long Non-Coding RNAs and the Regulatory Network Responsive to Arbuscular Mycorrhizal Fungi Colonization in Maize Roots.

Recently, long noncoding RNAs (lncRNAs) have emerged as vital regulators of many biological processes in animals and plants. However, to our knowledge no investigations on plant lncRNAs which respond to arbuscular mycorrhizal (AM) fungi have been reported thus far. In this study, maize roots colonized with AM fungus were analyzed by strand-specific RNA-Seq to identify AM fungi-responsive lncRNAs and construct an associated regulatory network. A total of 1837 differentially expressed protein coding genes (DEGs) were identified from maize roots with Rhizophagus irregularis inoculation. Many AM fungi-responsive genes were homologs to MtPt4, STR, STR2, MtFatM, and enriched pathways such as fatty acid biosynthesis, response to phosphate starvation, and nitrogen metabolism are consistent with previous studies. In total, 5941 lncRNAs were identified, of which more than 3000 were new. Of those, 63 lncRNAs were differentially expressed. The putative target genes of differentially expressed lncRNAs (DELs) were mainly related to phosphate ion transmembrane transport, cellular response to potassium ion starvation, and lipid catabolic processes. Regulatory network analysis showed that DELs might be involved in the regulation of bidirectional nutrient exchange between plant and AM fungi as mimicry of microRNA targets. The results of this study can broaden our knowledge on the interaction between plant and AM fungi.

Nematode diversity in four crop types (pea, apple, lavender and rose) in southern Bulgaria

Nematodes represent one of the largest phyla in the animal kingdom and are a key component of the soil microfauna (organisms with body width <0.2 mm). Being a widespread and diverse group, they display a wide range of adaptations and lifestyle traits. Their functional role in soil food-webs is mostly related to their feeding type. The majority of terrestrial nematodes feed on plant roots, bacteria and fungi, while a small group of plant associated species spend part or their whole life cycle in roots. Some plant-feeding species are known as important pests that can parasitize various crops causing adverse effects on yield and production quality. Their effective management requires accurate detection and identification. In the frame of the National Research Program "Healthy Foods for a Strong Bio-Economy and Quality of Life", selected groups of soil nematodes are used as bioindicators for assessing soil and plant health, and ecosystem services in several agricultural ecosystems. Nematode communities from four crop types (pea, apple, lavender and rose) in southern Bulgaria managed by conventional and organic farming were sampled and investigated. Here we present some preliminary results on pea, lavender and rose associated nematode diversity. Multiple core samples from 18 sampling plots were collected in June 2019. Nematodes were isolated from 200 g of soil by decanting and sieving method, fixed, dehydrated and mounted on permanent slides. Overall, over 60 genera belonging to five trophic groups were identified. Approximately half of the nematode genera found are obligatory plant- and plant/fungus feeders. Parasitic nematodes were represented by 12 genera, some of which include important pests known to cause severe damages on crops e.g. Meloidogyne Goeldi, 1889, Pratylenchus Filipjev, 1934, Pratylenchoides Winslow, 1958 and Tylenchorhynchus Cobb, 1913.

Strengthening mycorrhizal research in South America.

Strengthening mycorrhizal research in South America.

Metabolic alterations in pea leaves during arbuscular mycorrhiza development.

Arbuscular mycorrhiza (AM) is known to be a mutually beneficial plant-fungal symbiosis; however, the effect of mycorrhization is heavily dependent on multiple biotic and abiotic factors. Therefore, for the proper employment of such plant-fungal symbiotic systems in agriculture, a detailed understanding of the molecular basis of the plant developmental response to mycorrhization is needed. The aim of this work was to uncover the physiological and metabolic alterations in pea (Pisum sativum L.) leaves associated with mycorrhization at key plant developmental stages. Plants of pea cv. Finale were grown in constant environmental conditions under phosphate deficiency. The plants were analyzed at six distinct time points, which corresponded to certain developmental stages of the pea: I: 7 days post inoculation (DPI) when the second leaf is fully unfolded with one pair of leaflets and a simple tendril; II: 21 DPI at first leaf with two pairs of leaflets and a complex tendril; III: 32 DPI when the floral bud is enclosed; IV: 42 DPI at the first open flower; V: 56 DPI when the pod is filled with green seeds; and VI: 90–110 DPI at the dry harvest stage. Inoculation with Rhizophagus irregularis had no effect on the fresh or dry shoot weight, the leaf photochemical activity, accumulation of chlorophyll a, b or carotenoids. However, at stage III (corresponding to the most active phase of mycorrhiza development), the number of internodes between cotyledons and the youngest completely developed leaf was lower in the inoculated plants than in those without inoculation. Moreover, inoculation extended the vegetation period of the host plants, and resulted in increase of the average dry weight per seed at stage VI. The leaf metabolome, as analyzed with GC-MS, included about three hundred distinct metabolites and showed a strong correlation with plant age, and, to a lesser extent, was influenced by mycorrhization. Metabolic shifts influenced the levels of sugars, amino acids and other intermediates of nitrogen and phosphorus metabolism. The use of unsupervised dimension reduction methods showed that (i) at stage II, the metabolite spectra of inoculated plants were similar to those of the control, and (ii) at stages IV and V, the leaf metabolic profiles of inoculated plants shifted towards the profiles of the control plants at earlier developmental stages. At stage IV the inoculated plants exhibited a higher level of metabolism of nitrogen, organic acids, and lipophilic compounds in comparison to control plants. Thus, mycorrhization led to the retardation of plant development, which was also associated with higher seed biomass accumulation in plants with an extended vegetation period. The symbiotic crosstalk between host plant and AM fungi leads to alterations in several biochemical pathways the details of which need to be elucidated in further studies.