Endophytic entomopathogenic fungi such as Beauveria bassiana can serve as effective biostimulants and sustainable alternatives to chemical fertilizers. The interaction between endophytic microorganisms and garden strawberry plants is of particular interest due to the crop’s high sensitivity to abiotic and biotic stresses. This study evaluated the effects of endophytic colonization by B. bassiana on the growth, development, and acclimatization of strawberry plantlets under controlled ex vitro conditions. Inoculation was performed either by pre-soaking plantlet roots or by a single root watering with a B. bassiana conidial suspension (1 × 108 conidia/mL). Colonization rates ranged from 11.3 to 77.5
Pathogenesis-related (PR) proteins represent one of the mechanisms of plant defense under biotic stress. When a plant interacts with a pathogen, PR proteins amount increases, serving as the plant’s first line of defense. PR proteins possess a broad spectrum of enzymatic activity, and can reduce the negative effects caused by phytopathogens. In this study, we investigated the effect of nanocomposites (NCs)—substances consisting of nanoparticles (NPs) of Se or Mn chemically immersed into a polymer matrix of the natural polysaccharide arabinogalactan (AG)—on the PR genes expression in the in vitro grown potato plants infected with the phytopathogen Pectobacterium carotovorum (Pc). It was found that the POX, PR1, PR2, PR3, PR-5-18, PR6, PR9, and PR10 genes are induced twice and more in response to the Pc infection. Treatment of healthy plants with Se/AG NC induced the expression of PR3 and POX and suppressed the expression of the PR6 and PR9 genes. Treatment with Mn/AG NC increased the expression of the PR6 gene and decreased the expression of the PR9 gene. When Pc-infected potato plants were exposed to the NCs, a decrease in the expression of the following genes was noted: Se/AG NC—PR3 and PR6, Mn/AG NC—PR1, PR6, and PR9. Increased expression of the PR3 and PR9 genes was noted in the infected plants under the influence of Mn/AG NC. Thus, the NCs are capable to influence the expression of the potato PR genes.
Introgression from wild cereals is widely used to transfer disease resistance genes into the common wheat genome, but information on its impact on other important traits under unfavorable climatic conditions is limited. We studied stability of photosynthesis under different water supply in two wheat lines with introgression from Aegilops speltoides. The plants were grown in a climate chamber under optimal water supply and simulated soil drought. Gas exchange and chlorophyll fluorescence were measured using a portable GFS-3000 system. Activity of four enzymes of antioxidant protection and lipoxygenase, as well as the content of photosynthetic pigments, free proline, and soluble sugars were measured spectrophotometrically. It was shown that translocations from Ae. speltoides in chromosomes 1, 5, and 6 of the B genome in the drought-sensitive cv. Rodina (line 73/00i) positively impacted photosynthetic process, increasing the maximum quantum yield of PSII photochemistry under drought. The introgression from Ae. speltoides into the 5BL chromosome of the drought-resistant cv. Saratovskaya 29 (line S29(73/00i 5B)) induced adaptive responses associated with the regulation of the redox balance and non-photochemical quenching of chlorophyll. However, they did not have a significant negative impact on the processes of photosynthesis during drought. Lines 73/00i and S29(73/00i 5B), which are known for their resistance to fungal diseases, can also be useful in breeding to improve wheat’s adaptability to water scarcity.
Bread wheat Triticum aestivum L. (BBAADD) is one of the main agricultural crops. The genetic potential of its wild relatives and marker-assisted breeding technologies are actively used to improve tolerance to abiotic stress factors of bread wheat. Introgressive hybridization using Aegilops tauschii Coss. is considered to be one of the main approaches to increasing bread wheat drought tolerance. In this study, we have analyzed the effects of soil water deficit on physiological state of flag leaf tissues of six lines of cultivar Chinese Spring with introgressions from Ae. tauschii in 2D chromosome marked with microsatellite (SSR) markers. We determined the activity of superoxide dismutase, lipoxygenase, ascorbate-glutathione cycle enzymes, the content of free proline and soluble sugars in the leaves at the flowering stage. Considering our phenotyping data and the information on the positions of SSR marker and genes from GrainGene and EnsemblePlants databases, we concluded that the marker Xgwm296 on 2DS chromosome, as well as the markers Xgwm157, Xgwm1419 and Xgwm539 on chromosome 2DL are in a different way associated with drought tolerance. The introgression from Ae. tauschi into the area of marker Xgwm539 worsened the tolerance, while the same into the area of marker Xgwm1419 was neutral, and the introgressions into the area of markers Xgwm296 and Xgwm157 were favorable for tolerance to water deficit. Apparently, the key factors for drought tolerance of bread wheat in 2D chromosome are the genes of transcription factor of Myb and GTF superfamilies, as well as the glutathione-S-transferase and chaperonin Cpn60/GroEL/TCP-1 genes.
The Kunitz protease inhibitor-like protein (KPILP) of Nicotiana benthamiana is a stress-responsive glycoprotein that positively regulates intercellular transport of macromolecules and enhances host susceptibility to tobamoviruses. Its biological activity depends on three N-glycosylation sites, yet its subcellular localization and intracellular trafficking have remained uncharacterized. In this study, we demonstrate that KPILP follows the conventional secretory pathway, associating with trans-Golgi network (TGN)/early endosome compartments and dynamically shuttling to the plasma membrane (PM) via clathrin-mediated endocytosis. KPILP is not secreted into the apoplast but instead undergoes continuous TGN/PM/endosome cycling. Mutational analysis revealed that N-glycosylation at positions N60 and N86 is essential for proper vesicular targeting and PM recycling, whereas the N136 site is dispensable for intracellular trafficking despite being critical for KPILP regulatory function. Notably, absence of these glycosylation sites did not impair KPILP capacity to facilitate the local spread of tobamoviruses, suggesting that KPILP acts through distinct mechanisms to promote viral spread and to stimulate macromolecular transport. Collectively, our findings indicate that KPILP is a TGN/PM-associated protein the site-specific N-glycosylation of which defines its intracellular trafficking and localization.
The changes of the structural characteristics of mitochondrial membranes isolated from the pea (Pisum sativum L.) seedlings epicotyls under the influence of the nitric oxide donor (TNIC-thio) under water deficiency conditions were studied. Low-temperature structural rearrangements, which are associated with the “crystal–liquid crystal” transition, for the lipid and near-protein regions of the mitochondrial membranes of the pea seedlings epicotyls of the control group and under drought stress conditions were observed. The microviscosity of both regions of the mitochondrial membranes under water deficiency conditions was higher than for the control. Pre-treatment of seeds with the nitric oxide (II) donor caused a shift of the thermo-induced structural transition toward higher temperatures, indicating an increase a crystallinity of the pea seedlings epicotyls mitochondrial membranes. An increase in membrane crystallinity may suggest enhanced plant resistance to water deficiency. The increase in the microviscosity of mitochondrial membranes pre-treated with TNIC-thio under water deficiency was less pronounced compared to seeds not treated with the NO donor. However, the fluidity of the lipid bilayer of pea seedlings epicotyls mitochondria was restored only partially and did not reach control values.
This study examines the influence of soil and climate factors on the phytochemical composition of Trifolium pretense L. in the Republic of Tatarstan. A comparative analysis of six natural red clover populations was conducted in 2025 during the mass flowering period. The content of water-soluble phenolic compounds, flavonoids, carotenoids, ascorbic acid, and antioxidant activity (FRAP) were determined. A detailed polyphenolic profile was established using HPLC-UV. The maximum content of water-soluble phenolic compounds (14.249 ± 0.79 mg/g) and flavonoids (4.287 ± 0.34
Many strains of the genus Azospirillum are plant growth-promoting bacteria. Its beneficial effects on plants may be mediated by various mechanisms. Аzоsрirillа саn аssist in mitigаtiоn оf mаny kinds оf аbiоtiс strеss. Аzоsрirillum lесtins аrе glyсоprоtеins with diffеrеnt mоlеculаr mаssеs аnd сarbоhydrаtе sресifiсitiеs. Lесtins аrе роlyfunсtiоnаl mоlесulеs. This study examined the potential of lectins from two Azospirillum strains, Azospirillum brasilense Sp7 (epiphyte) and Azospirillum baldaniorum Sp245 (endophyte), to mitigate stress in wheat caused by simulated salinity. Pre-incubation of seeds with lectin solutions significantly improved germination energy and viability, and stimulated root growth in plant seedlings (root number and size). Along with improved growth and morphometric parameters, lectins also mitigated oxidative stress. Malondialdehyde (MDA) levels in lectin-treated plants were lower than in plants exposed to stress alone. Lectins can alter the ratio of photosynthetic pigments in plant cells under stress. The concentration of chlorophyll a and b, as well as the amount of carotenoids, increases. The lectin of the endophytic strain demonstrated higher functional activity, reaching the maximum effect earlier and at a lower concentration than the lectin of A. brasilense Sp7. The results indicate a positive effect of these glycoproteins on plant resistance.
The Siberian crab apple Malus baccata (L.) Borkh. is distinguished by an exceptionally high level of ascorbic acid (AsA) in its fruits relative to other members of the genus Malus. Yet, the fruit tissue metabolism of this species remains largely unexplored. To investigate the mechanisms underlying AsA accumulation, we performed a comparative analysis of fruits from M. baccata, its F1 hybrids, and M. domestica. Our experiments quantified endogenous AsA and the levels of metabolites of the main (galactose) and alternative (gulose, myo-inositol, and galacturonate) AsA biosynthetic pathways. For the first time, we assessed whether these pathways could contribute to AsA accumulation in the fruits of the aforementioned genotypes across different stages of development. To this end, the feeding method was employed. At all fruit developmental stages, endogenous AsA levels in the tissues of M. baccata and some of its F1 hybrids were significantly higher than the mean AsA content in M. domestica. While the galactose pathway (Smirnoff–Wheeler) was the dominant route of AsA biosynthesis in all genotypes examined, we also confirmed the potential involvement of alternative pathways, namely the galacturonate and myo-inositol pathways. Taken together, the findings indicate that alternative AsA biosynthesis pathways and the distinct pattern of AsA accumulation are responsible for the high ascorbate levels in M. baccata and its F1 hybrid fruits.
The need to find approaches to reduce the negative impact of temperature stress conditions on vineyards is driven by the increasing frequency of temperature fluctuations and the aggravation of damage. Therefore, the aim of this study was to investigate the effect of priming with physiologically active substances on mitigating freezing stress and the combined stress of drought and high temperature, as well as to identify the physiological basis for priming defense responses. The experiment was conducted on one-year-old vegetative seedlings of ‘Cabernet Sauvignon’ (freezing stress, −1.5°C) and ‘Kurchansky’ (combined drought and high-temperature stress, i.e., lack of irrigation and 40°C), which are sensitive to these types of temperature stress. Treatment of ‘Cabernet Sauvignon’ plants with combinations of methyl jasmonate and proline and salicylic acid and proline under freezing temperature conditions exhibited a protective effect. A reduction in electrolyte leakage in the treated variants indicated stabilization of cytoplasmic membranes and an increase in the adaptive potential of the plants. However, salicylic acid and proline treatment proved to be the most effective, as it was associated with coordinated changes across multiple facets of grape metabolism. Exogenous priming with salicylic acid and proline positively affected the expression of genes involved in abiotic stress protection, chlorophyll content in leaves, viniferin content, and soluble sugar levels, while reducing malondialdehyde content. Priming of ‘Kurchansky’ plants under combined drought and high-temperature conditions had a positive effect on the expression of some important protective genes. Priming also led to an increase in the chlorophyll stability index and soluble sugar content.
During pathologic process, plant physiology undergoes substantial changes, including altered biomass accumulation and synthesis of photosynthetic pigments and proteins. These processes can be modulated by resistance-inducing compounds with immunomodulatory activity. In the present study, we evaluated the effects of salicylic acid (SA; C7H6O3), chitosan (C6H11NO4)n, and silicon dioxide (SiO2) on disease development, morphometric traits, and the pigment system of lettuce plants, Lactuca sativa L., cv. Lalik, infected with Pseudomonas cichorii (Swingle 1925) Stapp 1928. Plants were grown in a non-circulating deep water culture hydroponic system under controlled conditions. Thirty-four days after germination, test compounds were applied by foliar spraying, followed by inoculation with Pseudomonas cichorii strain Pch12 (105 CFU/mL) via leaf petiole injection. Symptoms were recorded daily for 10 days, after which shoot weight, leaf length, and photosynthetic pigment content were determined. Delayed symptom development and better preservation of growth parameters in infected plants were observed after SiO2 treatment at 2 mg/plant. Compared with the infected control, SiO2-treated infected plants showed substantially higher shoot fresh weight (21.18 vs. 8.9 g) and leaf length (10.8 vs. 7.8 cm). In the samples treated with chitosan (3.1 mg/plant) and with SA (0.7 mg/plant), total chlorophyll content exceeded the infected control by 42.9 and 37.1
This study describes the creation of transgenic Berlin poplar (Populus × berolinensis K. Koch) expressing the Arabidopsis thaliana AtGA2ox2 gene, which encodes gibberellin 2-oxidase, and provides an initial evaluation of the resulting phenotypic effects. Genetic transformation of poplar was performed via an Agrobacterium-mediated technique using the pBI121 plasmid, where the AtGA2ox2 gene was placed under the control of the constitutive promoter of the cauliflower mosaic virus 35S RNA. The constitutive expression of AtGA2ox2 resulted in a distinct dwarf phenotype of poplar cultured in vitro. Compared to control plants, this transgenic poplar exhibited extremely reduced internode length and altered leaves morphology with a shape of inverted boat or spoon-shaped similar to those forming after satsuma dwarf virus infection in citrus trees. This dwarf phenotype precludes conventional microclonal vegetative propagation via apical and lateral buds. Furthermore, micropropagation via morphogenesis induction from callus is hindered by an altered hormonal balance within the transgenic cells, which exhibit low morphogenic capacity and tend to remain in a callus state. Regenerants derived from callus culture are difficult to root, and those that do root often fail to survive. The few successfully rooted plants exhibit extremely slow growth, with biomass accumulation restricted primarily to the formation of new rosette leaves. Furthermore, transferring these plantlets to ex vitro conditions is challenging due to the inherent fragility of both the shoots and the root systems. Consequently, the transgenic line is currently maintained in vitro as a callus culture and transferring of regenerated plants to ex vitro conditions requires further optimization to address their slow growth and poor vigor. Finally, while exogenous application of gibberellic acid to the shoot apices restores the wild-type phenotype, this effect is only transient.
Dehydrins (DHN) are protective proteins acting at the cellular level and increasing the resistance of plants to cold and water-deficient conditions. The DHN of gymnosperms remain poorly studied. Scots pine is adapted to cold conditions and moisture deficiency, which points to DHN importance for the stability of this species at the cellular level. To identify the DHN of Scots pine that are regulated by cold stress, callus lines were obtained on vegetative branches and buds of five Scots pine trees (Pinus sylvestris L.) and exposed to low positive temperatures. In response to cold treatment, there was an accumulation of superoxide anion, an increase in the level of lipid peroxidation and in the activity of peroxidase and superoxide dismutase enzymes, which indicates damage of membranes and the activation of protective mechanisms in the callus cells. When exposed to cold, there was an increase in the expression of six of the studied DHN genes, which had individual characteristics for each tree. Callus lines obtained on different Scots pine trees showed differences in the content and in the composition of DHN. In the calluses of the two lines a previously unidentified DHN with molecular weight 24 kDa appeared in response to cold. The content of DHN 70 kDa, which also accumulates in response to water deficiency, increased. The study indicates that P. sylvestris has DHN that are regulated with cold exposure, and DHN that can be regulated by both cold exposure and water deficiency.
The expression of dehydrin genes in crowns of winter wheat (Triticum aestivum L.) cultivars differing in frost resistance was studied according to the scheme: cold acclimation, freezing, and dehardening. It has been shown for the first time that, in addition to the previously described WCS120 dehydrins, some genes encoding proteins with the Y segment also play an equally important role in the frost resistance of winter wheat plants. The number of transcripts of these genes increased no less when exposed to negative temperatures after cold acclimation than in the case of WCS genes, and one of these genes, DHN3–B9 (wzy1-1), was activated 10 times more strongly than other highly inducible dehydrin genes. The dynamics of changes in the content of DHN mRNAs activated by cold and freezing were similar in winter wheat lines differing in frost resistance, but the number of transcripts of certain genes in the more resistant wheat cultivar increased more strongly. As shown by a comparative analysis of the profiles of changes in the mRNA content of dehydrin genes and their protein products, with the experimental scheme used in this work in the crowns of winter wheat during dehardening, the number of transcripts of dehydrin genes is significantly reduced to a level comparable to the level at the cold acclimation stage or even to the level of control values, and the degradation of protein products of genes is significantly suppressed—the content of proteins remains high at this stage.
Wheat (Triticum aestivum L.) is one of the world’s key grain crops. In cereals such as wheat, energy metabolism drives growth, development, and stress resistance, and is therefore central to crop productivity. The relevance of this work is due to the critical role of respiratory metabolism in ensuring wheat productivity during the reproductive period and the lack of data on the adult plant respiration during this period. The present study aimed to compare mitochondrial respiration and the associated parameters of redox metabolism in the vegetative and generative organs of winter (‘Irkutskaya’) and spring (‘Novosibirskaya 29’) wheat at the booting and anthesis stages. The study was conducted using vegetative (flag and sub-flag leaves, FL and SFL) and generative (spikes, Sp) organs. At the booting stage and compared to Sp, FL and SFL of both wheat varieties exhibited higher H2O2 and MDA levels and greater antioxidant enzyme activity, but lower water-soluble carbohydrate contents and mitochondrial respiration rates. Mitochondria from inflorescences were found to have higher respiration rates, a predominant contribution of the cytochrome pathway, and a high degree of coupling between oxidation and phosphorylation processes. The high activity of alternative oxidase in leaves, together with the high abundance of alternative NAD(P)H dehydrogenase (NDs-II) proteins, indicates an important role of mitochondrial energy-dissipating systems in green leaves during inflorescence development and anthesis. In general, wheat inflorescences are characterized by higher mitochondrial activity then wheat vegetative organs, especially during the booting stage. During the transition to anthesis, respiratory and redox metabolism parameters in inflorescences converge with those of leaves, possible due to a slowdown in growth processes and preparation for grain formation and filling.
Industrial emissions from aluminum production, containing a wide range of inorganic and organic pollutants, have a negative impact on trees. The expression and effectiveness of trees defense responses to technogenic stressors are largely determined by the functioning of their antioxidant system. Accordingly, the aim of this study was to investigate changes in the activity of main antioxidant enzymes in the needles of Scots pine (Pinus sylvestris L.) and Siberian larch (Larix sibirica Ledeb.)—dominant species in the boreal forests of the Irkutsk region—along a pollution gradient caused by aluminum smelter emissions, and to evaluate how these changes affect pollutant induced oxidative stress. The concentrations of fluorine, sulfur, heavy and light metals, as well as 16 priority polycyclic aromatic hydrocarbons (PAHs), were determined in the needles of both species. Based on cluster analysis, five pollution levels were identified: background, low, moderate, high, and critical. It was established that the accumulation capacity of L. sibirica for pollutants is higher than of P. sylvestris. The accumulation of pollutants in needles leads to oxidative stress, which is manifested by increased concentrations of H2O2 and malondialdehyde by 1.3–4.6 times. The most significant changes were observed in pine needles. Analysis of the enzymatic component of the antioxidant system revealed that its functioning has species-specific features. In P. sylvestris, peroxidase and catalase activity are higher than in L. sibirica, and pine peroxidase maintains activity over a wide pH range (3.0–11.0). Its activity remained high even under critical pollution, whereas catalase activity under the same load decreased by 1.5–2.0 times compared to background levels. Pine needles also showed greater diversity of peroxidase isoforms, which may indicate broader adaptive capabilities of its enzymatic system. Correlation analysis revealed a negative relationship between catalase activity and the content of fluorine, heavy metals and PAHs, and a positive relationship for peroxidase, which indicates different functions of these enzymes in the plant defense system activated by technogenic emissions. The obtained results confirm our hypothesis of significant differences in the defense systems of the two conifer species, manifested in the development of oxidative stress and the functioning of the antioxidant system. These differences should be taken into account when assessing the condition of forest ecosystems in industrial zones.
Climate change leads to specific hydrothermal conditions, which alter the health of plants and their associated microbial communities. Abiotic conditions have both positive and negative effects on pathogen development due to the specific physiological responses of grapevines to drought and heat stress. The aim of the study was to investigate the defense responses of grapevine and the development of phytopathogens under the influence of abiotic stressors of vegetation period. The study was conducted on two grape (Vitis vinifera L.) varieties—‘Riesling’ and ‘Bianca’—infected with compatible pathogens, Plasmopara viticola and Alternaria alternata, respectively. The abundance of epiphytic micromycetes increased with increasing adverse hydrothermal conditions, particularly, lack of precipitation and temperature above the long-term average. ‘Riesling’ susceptibility to P. viticola was associated with down-regulation of most defense genes upon infection under optimal and drought conditions at 24 hpi. Combined abiotic stress stimulated high level of defense genes expression, vinifirin production, high hydrogen peroxide levels and high peroxidase activity during P. viticola infection. This corresponded to minimal P. viticola infection rate. Low expression levels of PDF1 appeared to be responsible for decreased susceptibility of grapes to A. alternata. Expression patterns during the least efficient infection of A. alternata were similar in ‘Bianca’ and ‘Riesling’. This work contributes to our understanding of the impact of a combination of stress factors on grapevine plants during vegetation period. This new knowledge can be used to develop and refine plant protection systems.
Lamiaceae plants are valued for their organoleptic and biological properties, with extensive use in food, fragrance, and pharmaceutical sectors. The escalating spread of antibiotic resistance threatens global public health, stimulating the search for novel antimicrobial agents, particularly plant-derived essential oils. This study analyzes essential oils obtained by hydrodistillation from six Lamiaceae species native to the Republic of Tatarstan: Betonica officinalis L., Clinopodium vulgare L., Lamium maculatum L., Salvia tesquicola Klokov Pobed., Salvia verticillata L., and Stachys sylvatica L. Gas chromatography–mass spectrometry (GC–MS) revealed significant sesquiterpenoid diversity, with concentrations up to 45
The mechanisms underlying the development of extreme cold tolerance in woody plants involving lipids – including neutral lipids (NLs) and their fatty acids (FAs) in the adaptation to low sub-zero temperatures (down to −60°C) characteristic of the cryolithozone remain poorly understood. To elucidate the role of NLs in such adaptation, we investigated the patterns of seasonal changes in their composition and content in the shoots of Cajander larch (Larix cajanderi Mayr) growing in the natural conditions of Yakutia. Among NL, the focus was on 1,2,3-triacyl-sn-glycerols (TAG) as the dominant storage lipids, as well as sterol esters (SE) and waxes. Analysis of NL and their FAs was performed using HPTLC and GC-MS methods. It was found that in the annual cycle of L. cajanderi, the maximum accumulation of total lipids (TL) up to 83.2 mg/g dry weight and TAG up to 26.1
Photosynthetic apparatus in the chlorenchyma tissues of branches of perennial land plants has developed strategies that allow it to withstand significant temperature fluctuations throughout all seasons. In this study, we investigated the effect of freezing temperature treatment on the functional activity of the photosynthetic apparatus in the surface chlorenchyma of branches of the invasive maple Acer negundo L. We found that the maximum quantum yield of photosystem II in branches changed only slightly after freezing treatment, whereas the leaves inevitably died after this treatment. Analysis of fast chlorophyll fluorescence kinetics with high temporal resolution revealed that the operation of the water-oxidizing complex and the photosystem II reaction center remained unaffected by low-temperature treatment, whereas electron transfer beyond the primary electron acceptor QA was noticeably affected. Plastoquinone, which mediates electron transfer between photosystem II and I, was present at several-fold lower levels in branch chlorenchyma than in leaves, and its level was not affected by freezing. The levels of malondialdehyde, an indicator of oxidative membrane damage, significantly increased in leaves after freezing but remained low in the branch chlorenchyma. The total antioxidant capacity, assessed by ferric reducing/antioxidant power (FRAP) assay, was several times lower in the branch chlorenchyma compared to leaves. The obtained data demonstrate a marked difference between A. negundo L. leaves and branch chlorenchyma in the tolerance of the photosynthetic apparatus to low temperatures and contribute to our understanding of the physiological basis for the high freeze tolerance of the photosynthetic machinery.
