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The relevance of the Arctic regions' study is rapidly increasing due to the sensitive response of fragile ecosystems to climate change and anthropogenic pressure. The microbiome is an important component that determines the soils' functioning and an indicator of changes occurring in ecosystems. Rybachy Peninsula is the northernmost part of the continental European Russia and is almost completely surrounded by Barents Sea water. For the first time, the microbial communities of the Entic Podzol, Albic Podzol, Rheic Histosol and Folic Histosol as well as anthropogenically disturbed soils (chemical pollution and human impact, growing crops) on the Rybachy Peninsula were characterized using plating and fluorescence microscopy methods, in parallel with the enzymatic activity of soils. The amount and structure of soil microbial biomass, such as the total biomass of fungi and prokaryote, the length and diameter of fungal and actinomycete mycelium, the proportion of spores and mycelium in the fungal biomass, the number of spores and prokaryotic cells, the proportion of small and large fungal spores and their morphology were determined. In the soils of the peninsula, the fungal biomass varied from 0.121 to 0.669 mg/g soil. The biomass of prokaryotes in soils ranged from 9.22 to 55.45 μg/g of soil. Fungi predominated, the proportion of which in the total microbial biomass varied from 78.5 to 97.7%. The number of culturable microfungi ranged from 0.53 to 13.93 × 10 3 CFU/g in the topsoil horizons, with a maximum in Entic Podzol and Albic Podzol soils and a minimum in anthropogenically disturbed soil. The number of culturable copiotrophic bacteria varied from 41.8 × 10 3 cells/g in a cryogenic spot to 5551.3 × 10 3 cells /g in anthropogenically disturbed soils. The number of culturable oligotrophic bacteria ranged from 77.9 to 12,059.6 × 10 3 cells/g. Changes in natural soils because of anthropogenic impact and a change in vegetation types have led to a change in the structure of the community of soil microorganisms. Investigated tundra soils had high enzymatic activity in native and anthropogenic conditions. The β-glucosidase and urease activity were comparable or even higher than in the soils of more southern natural zone, and the activity of dehydrogenase was 2-5 times lower. Thus, despite the subarctic climatic conditions, local soils have a significant biological activity upon which the productivity of ecosystems largely depends. The soils of the Rybachy Peninsula have a powerful enzyme pool due to the high adaptive potential of soil microorganisms to the extreme conditions of the Arctic, which allows them to perform their functions even under conditions of anthropogenic interference.

Since chitooligosaccharides (COs) are water-soluble, biodegradable and nontoxic compounds, their application may be considered as a promising plant-protecting agent. However, the molecular and cellular modes of action of COs are not yet understood. In this study, transcriptional changes in pea roots treated with COs were investigated via RNA sequencing. Pea roots treated with the deacetylated CO8-DA at low concentration (10 -5 М) were harvested 24 h after treatment and their expression profiles were compared against medium-treated control plants. We observed 886 differentially expressed genes (fold change ≥ 1; p-value < 0.05) 24 h after treatment with CO8-DA. Gene Ontology term over-representation analysis allowed us to identify the molecular functions of the genes activated in response to CO8-DA treatment and their relation to biological processes. Our findings suggest that calcium signaling regulators and MAPK cascade play a key role in pea plant responses to treatment. Here we found two MAPKKKs, the PsMAPKKK5 and PsMAPKKK20, which might function redundantly in the CO8-DA-activated signaling pathway. In accordance with this suggestion, we showed that PsMAPKKK knockdown decreases resistance to pathogenic Fusarium culmorum fungi. Therefore, analysis showed that typical regulators of intracellular signal transduction pathways involved in triggering of plant responses via CERK1 receptors to chitin/COs in Arabidopsis and rice may also be recruited in legume pea plants., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Kozyulina, Pavlova, Kantsurova (Rudaya), Bovin, Shirobokova, Dolgikh, Dymo and Dolgikh.)

Traditional sanitation practices remain the main strategy for controlling Bombyx mori infections caused by microsporidia Nosema bombycis . This actualizes the development of new approaches to increase the silkworm resistance to this parasite. Here, we constructed a mouse scFv library against the outer loops of N. bombycis ATP/ADP carriers and selected nine scFv fragments to the transporter, highly expressed in the early stages of the parasite intracellular growth. Expression of selected scFv genes in Sf9 cells, their infection with different ratios of microsporidia spores per insect cell, qPCR analysis of N. bombycis PTP2 and Spodoptera frugiperda COXI transcripts in 100 infected cultures made it possible to select the scFv fragment most effectively inhibiting the parasite growth. Western blot analysis of 42 infected cultures with Abs against the parasite β-tubulin confirmed its inhibitory efficiency. Since the VL part of this scFv fragment was identified as a human IgG domain retained from the pSEX81 phagemid during library construction, its VH sequence should be a key antigen-recognizing determinant. Along with the further selection of new recombinant Abs, this suggests the searching for its natural mouse VL domain or "camelization" of the VH fragment by introducing cysteine and hydrophilic residues, as well as the randomization of its CDRs.

Heterotrimeric G-proteins regulate plant growth and development as master regulators of signaling pathways. In legumes with indeterminate nodules (e.g., Medicago truncatula and Pisum sativum ), the role of heterotrimeric G-proteins in symbiosis development has not been investigated extensively. Here, the involvement of heterotrimeric G-proteins in M. truncatula and P. sativum nodulation was evaluated. A genome-based search for G-protein subunit-coding genes revealed that M. truncatula and P. sativum harbored only one gene each for encoding the canonical heterotrimeric G-protein beta subunits, MtG beta 1 and PsG beta 1, respectively. RNAi-based suppression of MtGbeta1 and PsGbeta1 significantly decreased the number of nodules formed, suggesting the involvement of G-protein beta subunits in symbiosis in both legumes. Analysis of composite M. truncatula plants carrying the pMtGbeta1:GUS construct showed β-glucuronidase (GUS) staining in developing nodule primordia and young nodules, consistent with data on the role of G-proteins in controlling organ development and cell proliferation. In mature nodules, GUS staining was the most intense in the meristem and invasion zone (II), while it was less prominent in the apical part of the nitrogen-fixing zone (III). Thus, MtG beta 1 may be involved in the maintenance of meristem development and regulation of the infection process during symbiosis. Protein-protein interaction studies using co-immunoprecipitation revealed the possible composition of G-protein complexes and interaction of G-protein subunits with phospholipase C (PLC), suggesting a cross-talk between G-protein- and PLC-mediated signaling pathways in these legumes. Our findings provide direct evidence regarding the role of MtG beta 1 and PsG beta 1 in symbiosis development regulation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Bovin, Pavlova, Dolgikh, Leppyanen and Dolgikh.)

The IPD3/CYCLOPS transcription factor was shown to be involved in the regulation of nodule primordia development and subsequent stages of nodule differentiation. In contrast to early stages, the stages related to nodule differentiation remain less studied. Recently, we have shown that the accumulation of cytokinin at later stages may significantly impact nodule development. This conclusion was based on a comparative analysis of cytokinin localization between pea wild type and ipd3/cyclops mutants. However, the role of cytokinin at these later stages of nodulation is still far from understood. To determine a set of genes involved in the regulation of later stages of nodule development connected with infection progress, intracellular accommodation, as well as plant tissue and bacteroid differentiation, the RNA-seq analysis of pea mutant SGEFix - -2 ( sym33 ) nodules impaired in these processes compared to wild type SGE nodules was performed. To verify cytokinin's influence on late nodule development stages, the comparative RNA-seq analysis of SGEFix - -2 ( sym33 ) mutant plants treated with cytokinin was also conducted. Findings suggest a significant role of cytokinin in the regulation of later stages of nodule development.

Urbanization in the Arctic results in considerable and still poorly known environmental consequences. The effect of urbanization on soil microbiome-an ecosystem component highly sensitive to anthropogenic disturbance-remains overlooked for the Arctic region. The research compared chemical and microbial properties of the natural Podzol soils and urban soils of Murmansk-the largest Arctic city. Particular attention was given to the profile distribution, which is almost completely ignored by most microbial studies. Soil microbiome was investigated by the quantitative indicators based on fluorescence microscopy (microbial biomass) and PCR real-time methods (amount of rRNA genes copies of archaea, bacteria, and fungi). The principal changes in urban soils' properties compared to the natural references included a shift in pH and an increase in C and nutrients' contents, especially remarkable for the subsoil. The numbers of rRNA genes copies of archaea, bacteria, and fungi in urban topsoils (10 6 -10 10 , 10 9 -10 10 , and 10 7 -10 9 , respectively) were lower than in Podzol; however, the opposite pattern was shown for the subsoil. Similarly, the total microbial biomass in urban topsoils (0.55-0.75 mg g -1 ) was lower compared to the 1.02 mg g -1 in Podzols, while urban subsoil microbial biomass was 2-2.5 times higher than in the natural conditions. Both for urban and natural soils and throughout the profiles, fungi were dominated by mycelium forms; however, the ratios of mycelium-spores were lower, and the amount of thin mycelium was higher in urban soils than in natural Podzols. Urbanization in the Arctic altered soil morphological and chemical properties and created a new niche for microbial development in urban subsoils; its contribution to biodiversity and nutrient cycling promises to become increasingly important under projected climate change.

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 Ps LYK9 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 Ps LYK9 in symbiosis development with AM fungi. Additionally, Ps LYK9 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 Ps LYK9 in the regulation of interactions with pathogenic and AM fungi. Co-immunoprecipitation assay revealed that Ps LYK9 and two proposed co-receptors, Ps LYR4 and Ps LYR3, can form complexes. Analysis of binding capacity showed that Ps LYK9 and Ps LYR4, 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 Ps LYK9 and Ps LYR4 can trigger a signal pathway that stimulates the immune response in peas. However, Ps LYR3 seems not to be involved in the perception of CO4-5, as a possible co-receptor of Ps LYK9.

Single three-amino acid loop extension (TALE) homeodomain proteins, including the KNOTTED-like (KNOX) and BEL-like (BELL) families in plants, usually work as heterodimeric transcription factor complexes to regulate different developmental processes, often via effects on phytohormonal pathways. Nitrogen-fixing nodule formation in legumes is regulated by different families of homeodomain transcription factors. Whereas the role of KNOX transcription factors in the control of symbiosis was studied early, BELL transcription factors have received less attention. Here, we report the identification and expression analysis of BELL genes in the legume plants Medicago truncatula and Pisum sativum , which are involved in regulating symbiosis initiation and development. A more precise analysis was performed for the most significantly upregulated PsBELL1-2 gene in pea. We found that the PsBELL1-2 transcription factor could be a potential partner of PsKNOX9. In addition, we showed that PsBELL1-2 can interact with the PsDELLA1 (LA) protein-regulator of the gibberellin pathway, which has a previously demonstrated important role in symbiosis development.

Background and Aims: Recent findings indicate that Nod factor signalling is tightly interconnected with phytohormonal regulation that affects the development of nodules. Since the mechanisms of this interaction are still far from understood, here the distribution of cytokinin and auxin in pea (Pisum sativum) nodules was investigated. In addition, the effect of certain mutations blocking rhizobial infection and subsequent plant cell and bacteroid differentiation on cytokinin distribution in nodules was analysed., Methods: Patterns of cytokinin and auxin in pea nodules were profiled using both responsive genetic constructs and antibodies., Key Results: In wild-type nodules, cytokinins were found in the meristem, infection zone and apical part of the nitrogen fixation zone, whereas auxin localization was restricted to the meristem and peripheral tissues. We found significantly altered cytokinin distribution in sym33 and sym40 pea mutants defective in IPD3/CYCLOPS and EFD transcription factors, respectively. In the sym33 mutants impaired in bacterial accommodation and subsequent nodule differentiation, cytokinin localization was mostly limited to the meristem. In addition, we found significantly decreased expression of LOG1 and A-type RR11 as well as KNOX3 and NIN genes in the sym33 mutants, which correlated with low cellular cytokinin levels. In the sym40 mutant, cytokinins were detected in the nodule infection zone but, in contrast to the wild type, they were absent in infection droplets., Conclusions: In conclusion, our findings suggest that enhanced cytokinin accumulation during the late stages of symbiosis development may be associated with bacterial penetration into the plant cells and subsequent plant cell and bacteroid differentiation., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The key event that initiates nodule organogenesis is the perception of bacterial signal molecules, the Nod factors, triggering a complex of responses in epidermal and cortical cells of the root. The Nod factor signaling pathway interacts with plant hormones, including cytokinins and gibberellins. Activation of cytokinin signaling through the homeodomain-containing transcription factors KNOX is essential for nodule formation. The main regulators of gibberellin signaling, the DELLA proteins are also involved in regulation of nodule formation. However, the interaction between the cytokinin and gibberellin signaling pathways is not fully understood. Here, we show in Pisum sativum L. that the DELLA proteins can activate the expression of KNOX and BELL transcription factors involved in regulation of cytokinin metabolic and response genes. Consistently, pea la cry-s ( della1 della2 ) mutant showed reduced ability to upregulate expression of some cytokinin metabolic genes during nodulation. Our results suggest that DELLA proteins may regulate cytokinin metabolism upon nodulation.

For the first time were the results of studies on influence of main kinds of local anthropogenic factors on soil emission of biogenic greenhouse gases (CO2, CH4, and N2O) in permafrost ecosystems of Arctic and North-Boreal zones of the Russian Federation, and also of the Spitsbergen Archipelag summarized. Different types of land use can, depending on their manner, lead to significant enhancing or suppression of soil CO2 emission. On average, anthropogenic factors (AFs), acting in concert, favor the enhancement of local CO2 soil emission, promoting, at the same time, an increase in its dispersion. AFs directly influence the microbial-root respiration in soil, modify the soil itself, and indirectly affect important natural respiration regulators, phytomass reserves in particular, which makes them primary factors with relation to respiration pattern. AFs influence also the emission of other biogenic greenhouse gases (CH4 and N2O), though this influence can be exercised in different ways. Methane emission is mediated by degree of the territory drainage. However, in all studied cases, AFs have led to source reduction or sink intensification of this gas from the atmosphere. Unlike methane emission, N2O emission increased under the influence of AFs considered. As for the whole complex of AFs that impacts the carbon balance and fluxes of CO2 in cryogenic ecosystems, its role is expressed through the enhancement of soil respiration at the beginning of the cold season, when AFs are capable of soil emission increasing, at the level of meso-landscape, almost by 50%.

We consider a chain of one-dimensional dipole moments connected to two thermal baths with different temperatures. The system is in nonequilibrium steady state and heat flows through it. Assuming that fluctuation of the dipole moment is a small parameter, we develop an analytically solvable model for the problem. The effect of disorder is introduced by randomizing the positions of the dipole moments. We show that the disorder leads to Anderson-like transition from conducting to a thermal insulating state of the chain. It is shown that considered chain supports both ballistic and diffusive heat transports depending on the strength of the disorder. We demonstrate that nonequilibrium leads to the emergence of the long-range order between dipoles along the chain and make the conjecture that the interplay between nonequilibrium and next-to-nearest-neighbor interactions results in the emergence of long-range correlations in low-dimensional classical systems.

A nonlinear theory of nanometer capillary waves is developed that takes curvature dependence of the surface tension coefficient (Tolman's nonlinearity) into account. Estimations are given that indicate the importance of Tolman's nonlinearity for thermocapillary waves.