Root Tissues Research Articles

Efficacy of L-arabinose in managing cucumber Fusarium wilt and the underlying mechanism of action.

Cucumber Fusarium wilt (CFW), triggered by Fusarium oxysporum f. sp. cucumerinum, leads to substantial yield reductions in global cucumber (Cucumis sativus L.) production. Common management strategies for CFW include soil fumigation, grafting, and crop rotation. However, these methods have limitations regarding safety and efficacy stability, necessitating the development of new, cost-effective, and eco-friendly control strategies. Our prior research demonstrated that L-arabinose, an inexpensive and safe sugar commonly used in food and beverages, effectively suppressed bacterial wilt in tomatoes. This study explores the potential of L-arabinose in managing CFW and investigates its mechanism of action. Soil applications of L-arabinose, ranging from 0.00001 to 0.01%, effectively suppressed CFW. The most significant suppressive effect was observed at 0.01%, reducing the disease severity index by 67.5% compared to the control treatment. Microscopic examination of transverse root sections showed that pathogen hyphae colonized the epidermis but seldom penetrated the cortical layer of roots in L-arabinose-treated seedlings. In contrast, the entire root tissue of control seedlings was colonized by the pathogen. Quantitative real-time PCR revealed a significant increase in the expression of defense-related genes dependent on salicylic acid, jasmonic acid, and ethylene in L-arabinose-treated plants compared to control plants, 6 and 10 days post pathogen inoculation. This study demonstrated that soil application of L-arabinose can effectively suppress CFW by priming root tissues for multiple defense signaling pathways. Therefore, L-arabinose holds potential as a new fungicide for managing CFW. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Stilbene production as part of drought adaptation mechanisms in cultivated grapevine (Vitis vinifera L.) roots modulates antioxidant status.

Stilbenes, naturally occurring polyphenolic secondary metabolites, play a pivotal role in adaptation of various plant species to biotic and abiotic factors. Recently, increased attention has been directed toward their potential to enhance plant stress tolerance. We evaluated drought tolerance of three grapevine varieties grown with different levels of water deficit. Throughout, we studied physiological mechanisms associated with drought stress tolerance, particularly stilbene accumulation in root tissues, using HPLC. Additionally, we explored the possible relationship between antioxidant potential and stilbene accumulation in response to water deficit. The results underscore the detrimental impact of water deficit on grapevine growth, water status, and membrane stability index, while revealing varying tolerance among the studied genotypes. Notably, Syrah variety had superior drought tolerance, compared to Razegui and Muscat d'Italie grapes. Under severe water deficit, Syrah exhibited a substantial increase in levels of stilbenic compounds, such as t-resveratrol, t-piceatannol, t-ɛ-viniferin, and t-piceid, in root tissues compared to other genotypes. This increase was positively correlated with total antioxidant activity (TAA), emphasizing the active role of resveratrol and its derivatives in total antioxidant potential. This demonstratres the potential involvement of resveratrol and its derivatives in enhancing antioxidant status of the drought-tolerant Syrah grape variety. Our findings suggest that these stilbenes may function as valuable markers in grapevine breeding programs, offering novel insights for the sustainable cultivation of grapevines in water-limited environments.

Spatiotemporal diversity of bacterial endophyte microbiome of mandarin (Citrus reticulata) in the northern Persian Gulf and its HCN production and N2 fixation.

Endophytes are symbionts that live in healthy plants and potentially improve the health of plant holobionts. Here, we investigated the bacterial endophyte community of Citrus reticulata grown in the northern Persian Gulf. Bacteria were isolated seasonally from healthy trees (root, stem, bark, trunk, leaf, and crown tissues) in four regions of Hormozgan province (i.e., Ahmadi, Siyahoo, Sikhoran, Roudan), a subtropical hot region in Iran. A total of 742 strains from 17 taxa, 3 phyla, and 5 orders were found, most of which belonged to Actinobacteria (Actinobacteriales) as the dominant group, followed by Firmicutes (Bacillales), Proteobacteria (Sphingomonadales, Rhizobiales), and Cyanobacteria (Synechoccales). The genera included Altererythrobacter, Arthrobacter, Bacillus, Cellulosimicrobium, Curtobacterium, Kocuria, Kytococcus, Methylopila, Mycobacterium, Nocardioides, Okiabacterium, Paracraurococcus, and Psychrobacillus. The most frequently occurring species included Psychrobacillus psychrodurans, Kytococcus schroetri, and Bacillus cereus. In addition, the overall colonization frequency and variability of endophytes were higher on the trunks. The leaves showed the lowest species variability in all sampling periods. The frequency of endophyte colonization was also higher in summer. The Shannon-Wiener (H') and Simpson indices varied with all factors, i.e., region, season, and tissue type, with the maximum in Roudan. Furthermore, 52.9% of the strains were capable of nitrogen fixation, and 70% produced antagonistic hydrogen cyanide (HCN). Thus, C. reticulata harbors a variety of bioactive bacterial endophytes that could be beneficial for host fitness in such harsh environments.

A pearl millet plasma membrane protein, PgPM19, facilitates seed germination through the negative regulation of abscisic acid-associated genes under salinity stress in Arabidopsis thaliana.

The pearl millet gene PgPM19 inhibits seed dormancy by negatively regulating the ABA biosynthesis and ABA signaling pathways in response to salinity stress in Arabidopsis. Abscisic acid (ABA) plays a pivotal role in orchestrating plant stress responses and development. However, how the ABA signal is transmitted in response to stresses remains primarily uncertain, particularly in monocotyledonous plants. In this study, PgPM19, a gene whose expression is induced by drought, salinity, heat, and ABA in both leaf and root tissues, was isolated from pearl millet. The expression of PgPM19 in yeast cells did not influence their growth when subjected to mannitol, sorbitol, or NaCl stress. However, Arabidopsis plants overexpressing PgPM19 (PgPM19_OE plants) exhibited increased germination rates, greater fresh weights and longer roots under salinity stress during germination, compared to wild-type (WT) plants. Conversely, the pm19L1 (SALK_075435) mutant, featuring a transfer DNA insertion in a closely related PgPM19 homolog (AT1G04560) in Arabidopsis, demonstrated reduced germination rates and smaller fresh weights under salinity-stressed condition than did WT and PgPM19_OE plants. A pivotal ABA biosynthesis gene, NCED3, ABA signaling pathway genes, such as PYL6 and SnRK2.7, alongside downstream ABI genes and stress-responsive genes RAB28 and RD29, were downregulated in PgPM19_OE plants, as evidenced by both transcriptome analysis and quantitative reverse transcription-PCR. These findings raise the possibility that PgPM19 is involved in regulating seed germination by mediating ABA biosynthesis and signaling pathway in response to salinity stress in Arabidopsis. This study contributes to a better understanding of PgPM19 in response to salinity stress and establishes a foundation for unraveling the crosstalk of stress responses and ABA in Arabidopsis and other plant species.

Root physiological and morphology processes co-regulate the growth of Chinese-fir saplings in response to warming and precipitation reduction in the sub-tropical regions

Subtropical China is projected to experience elevated temperature greater than the mean global temperature increase and is accompanied by reduced precipitation. The plasticity of roots to changing environment strongly influences ecosystem feedbacks to climate change. However, knowledge gaps on the individual and combined effects of warming and precipitation reduction on root systems hinder our ability to accurately predict the growth and adaptability of forests under future climate change. To examine the effects of warming (W) and precipitation reduction (P) on roots physiology and morphology of Chinese-fir saplings, we used a randomized complete block design with factorial soil warming (ambient, ambient + 5℃) and precipitation reduction (ambient, ambient-50%) treatments. A full excavation method was adopted to obtain roots, then we measured the root physiology (osmoregulatory substances, oxidant substances, protective enzymes, endogenous hormones), morphology (specific root length, SRL; surface root area, SRA; root tissue density, RTD). The content of carbon and nitrogen, isotopes (δ13C and δ15N); soil temperature, soil moisture and sapling growth were also measured. We found that compared with the control, W decreased the abscisic acid (IAA) content; P increased the contents of hydrogen peroxide (H2O2) and proline (Pro), and decreased the contents of IAA and cytokinin (CTK); warming plus precipitation reduction (WP) increased the Pro content, and decreased the contents of IAA and CTK. In addition, the effects of W and P on root morphology varied with soil depth and root diameter class. W, P, and WP all increased fine root SRL and SRA in deep soil. Warming and precipitation reduction could affect physiological traits (e.g. non-enzymatic substances and antioxidant enzymes) and subsequently morphological traits via influencing soil environment and root tissue chemistry. Collectively, the results indicated that Chinese-fir saplings responded to warming and precipitation reduction by comprehensive regulation of the non-enzymatic substances (e.g., osmotic substances and endogenous hormones) of fine roots and changing root morphological characteristics in deep soil.

Comparative RNA-seq analysis reveals transposable element-mediated transcriptional reprogramming under phosphorus-starvation stress in rice (Oryza sativa L.)

Phosphorus (P) deficiency hinders crop productivity of 50 % of the rice grown in Asia, Africa, and South America. About 90 % of the phosphate in fertilizers applied to the crops gets fixed in the soil, reducing its availability to plants. This necessitates increased use of phosphatic fertilizers leading to higher cost of cultivation and environmental pollution. Although molecular mechanisms of P-deficiency tolerance in rice are being deciphered, the role of transposable elements (TEs) in transcriptional reprogramming under P-starvation/deficiency stress has not yet been reported. To investigate the role of Pup1 QTL in controlling TE-mediated reprogramming of gene expression, a pair of contrasting rice [Pusa-44 and its Near-Isogenic Line (NIL)-23] genotypes were grown hydroponically under control and stressed (0 ppm Pi) conditions. Comparative RNA-seq analysis of root and shoot tissues from 45-day-old plants of the rice genotypes revealed TE-mediated transcriptional reprogramming affecting biological processes and cellular components. Significantly up-regulated expression of several TEs under P-starvation stress, controlled by Pup1 QTL, particularly in shoots of NIL-23 indicates their crucial role in P homeostasis. Moreover, comparative physio-biochemical analyses confirmed the stress tolerance of NIL-23. Several biological processes including DNA replication/repair, metabolism, signaling, and phosphorylation were modulated through differential (mainly up-regulated) expression of TEs (controlled by Pup1 QTL) in shoots of NIL-23 under P-starvation. To the best of our knowledge, this is a pioneer study on the role of TEs in reprogramming biological processes/molecular functions/cellular components involved in P-use efficiency in rice under stress. The findings advance our understanding of the functions of Pup1 to improve the P-use efficiency/productivity of rice in P-deficient soils.

Impacts of root exudates on the toxic response of Chrysanthemum coronarium L. to the co-pollution of nanoplastic particles and tetracycline

Nano polystyrene (PS) particles and antibiotics universally co-exist, posing a threat to crop plants and hence human health, nevertheless, there is limited research on their combined toxic effects along with major influential factors, especially root exudates, on crop plants. This study aimed to investigate the response of Chrysanthemum coronarium L. to the co-pollution of nanoplastics and tetracycline (TC), as well as the effect of root exudates on this response. Based on a hydroponic experiment, the biochemical and physiological indices of Chrysanthemum coronarium L. were measured after 7 days of exposure. Results revealed that the co-pollution of TC and PS caused significant oxidative damage to the plants, resulting in reduced biomass. Amongst the two contaminants, TC played a more prominent role. PS could enter the root tissue, and the uptake of TC and PS by plant roots was synergetic. Malic acid, oxalic acid, and formic acid could explain 65.1% of the variation in biochemical parameters and biomass of the roots. These compounds affected the photosynthesis and biomass of Chrysanthemum coronarium L. by gradually lowering root reactive oxygen species (ROS) and leaf ROS. In contrast, the impact of rhizobacteria on the toxic response of the plants was relatively minor. These findings suggested that root exudates could alleviate the toxic response of plants to the co-pollution of TC and PS. This study enhances our understanding of the role of root exudates, providing insights for agricultural management and ensuring food safety.

The secreted protein FonCHRD is essential for vegetative growth, asexual reproduction, and pathogenicity in watermelon Fusarium wilt fungus

Fungal pathogens often secrete numerous effectors to interfere with and/or suppress plant immunity to promote their infection. Watermelon Fusarium wilt, caused by the soil-borne fungus Fusarium oxysporum f. sp. niveum (Fon), is one of the devastating diseases that severely affect the watermelon industry. Here, we report the function of a candidate effector protein, FonCHRD, in Fon. FonCHRD harbors a chordin (CHRD) domain of unknown function and has a signal peptide with secretion activity. FonCHRD shows a relatively high expression level in Fon marcoconidia and is inducible by watermelon root tissues. Phenotypic analysis of the targeted deletion mutant revealed that FonCHRD plays roles in vegetative growth, asexual reproduction, and conidial morphology of Fon, while it is not involved in spore germination as well as cell wall, oxidative and salt stress responses. Deletion of FonCHRD impaired the ability to colonize and spread within host plants, significantly reducing its virulence on watermelon. FonCHRD is distributed across multiple compartments of plant cells but can target to the apoplast space in plants. FonCHRD inhibits the INF1- and Bcl2-associated X protein-triggered cell death and defense gene expression in transiently expressed Nicotiana benthamiana leaves. These findings suggest that FonCHRD is essential for Fon pathogenicity by modulating invasive growth and spreading abilities as well as by suppressing plant immune responses.

Quantitative Proteomic Analysis of Brassica Napus Reveals Intersections Between Nutrient Deficiency Responses.

Macronutrients such as nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) are critical for plant growth and development. Field-grown canola (Brassica napus L.) is supplemented with fertilizers to maximize plant productivity, while deficiency in these nutrients can cause significant yield loss. A holistic understanding of the interplay between these nutrient deficiency responses in a single study and canola cultivar is thus far lacking, hindering efforts to increase the nutrient use efficiency of this important oil seed crop. To address this, we performed a comparative quantitative proteomic analysis of both shoot and root tissue harvested from soil-grown canola plants experiencing either nitrogen, phosphorus, potassium or sulphur deficiency. Our data provide critically needed insights into the shared and distinct molecular responses to macronutrient deficiencies in canola. Importantly, we find more conserved responses to the four different nutrient deficiencies in canola roots, with more distinct proteome changes in aboveground tissue. Our results establish a foundation for a more comprehensive understanding of the shared and distinct nutrient deficiency response mechanisms of canola plants and pave the way for future breeding efforts.

Invasive plants and their root traits are linked to the homogenization of soil microbial communities across the United States

Although the impacts of invasive plants on soil ecosystems are widespread, the role and impacts of invader root traits in structuring microbial communities remain poorly understood. Here, we present a macroecological study investigating how plant invaders and their root traits affect soil microbial communities, spanning data from 377 unique plots across the United States sampled multiple times, totaling 632 sampling events and 94 invasive plant species. We found that native and invasive plants harbor different root traits on average, with invasive plants possessing higher specific root lengths and native plants having higher root tissue density. We also show that soil microbial communities experiencing heavy plant invasions were more similar to each other in composition across ecosystem types and geographical regions than plots with higher proportions of native plants, which displayed highly variable microbial communities across the continent. Root traits of invasive plants in highly invaded plots explained two times more variation in microbial composition than native plants. This work represents an important step toward understanding macroscale and cross-scale patterns of the relationship between plant invasions, root traits, and soil microbial composition. Our findings provide insights into how invasive plants may impact ecosystem functioning at the macroscale via their homogenizing influence on microbial communities.

The effect of spermidine supplementation on polyamine metabolism and Fusarium infection in Linum usitatissimum

Flax (Linum usitatissimum) is a valuable industrial crop in temperate climate zones. However, the prevalence of fungal diseases, particularly those caused by Fusarium oxysporum sp. linii, poses a substantial threat, leading to significant crop losses and diminished interest in flax cultivation. In this study, flax plants were treated with spermidine and subsequently infected with Fusarium oxysporum to investigate multiple aspects: (1) the uptake of exogenous spermidine by the plants, (2) the impact of this uptake on the levels of other polyamines and the expression of polyamine biosynthesis genes, and (3) the effects of fungal infection on these parameters. The results demonstrated that flax plants effectively absorb spermidine, leading to substantial changes in the levels of polyamines and the expression of related genes in both roots and shoots. Notably, spermidine treatment resulted in significant alterations in the levels of putrescine and spermine, as well as in the transcript levels of key genes involved in polyamine biosynthesis. Moreover, Fusarium oxysporum infection itself induced changes in polyamine content and gene expression, which varied between root and shoot tissues. When spermidine-treated plants were infected with Fusarium oxysporum, a more complex response was observed, characterized by modifications in polyamine levels and gene expression that suggest an enhanced defense mechanism against the pathogen. These findings indicate that polyamine treatment not only affects the infection process but also modulates the plant's internal polyamine metabolism and gene expression, contributing to an improved resistance to fungal attack. This study highlights the potential of spermidine as a protective agent in flax and provides a foundation for further exploration of polyamine-related defense mechanisms.

Integrated stress responses in okra plants (cv. ‘’Meya’]: unravelling the mechanisms underlying drought and nematode co-occurrence

BackgroundClimate change threatens sub-Saharan Africa’s agricultural production, causing abiotic and biotic stressors. The study of plant responses to joint stressors is crucial for understanding molecular processes and identifying resilient crops for global food security. This study aimed to explore the shared and tailored responses of okra plants (cv. ‘’Meya’), at the biochemical and molecular levels, subjected to combined stresses of drought and Meloidogyne incognita infection.DesignThe study involved 240 okra plants in a completely randomized design, with six treatments replicated 20 times. Okra plants were adequately irrigated at the end of every 10-days water deficit that lasted for 66 days (D). Also, the plants were infected with M. incognita for 66 days and irrigated at 2-days intervals (R). The stresses were done independently, in sequential combination (D before R and R before D) and concurrently (R and D). All biochemical and antioxidant enzyme assays were carried out following standard procedures.ResultsSignificant reductions in leaf relative water content were recorded in all stressed plants, especially in leaves of plants under individual drought stress (D) (41.6%) and plants stressed with root-knot nematode infection before drought stress (RBD) (41.4%). Malondialdehyde contents in leaf tissues from plants in D, nematode-only stress (RKN), drought stress before root-knot nematode infection (DBR), RBD, and concurrent drought-nematode stress (RAD) significantly increased by 320.2%, 152.9%, 186.5%, 283.7%, and 109.6%, respectively. Plants in D exhibited the highest superoxide dismutase activities in leaf (147.1% increase) and root (105.8% increase) tissues. Catalase (CAT) activities were significantly increased only in leaves of plants in D (90.8%) and RBD (88.9%), while only roots of plants in D exhibited a substantially higher CAT activity (139.3% increase) in comparison to controlled plants. Okra plants over-expressed NCED3 and under-expressed Me3 genes in leaf tissues. The NCED3 gene was overexpressed in roots from all treatments, while CYP707A3 was under-expressed only in roots of plants in RBD and RKN. CYP707A3 and NCED3 were grouped as closely related genes, while members of the Me3 genes were clustered into a separate group.ConclusionThe biochemical and molecular responses observed in okra plants (cv. ‘’Meya’) subjected to combined stresses of drought and Meloidogyne incognita infection provide valuable insights into enhancing crop resilience under multifaceted stress conditions, particularly relevant for agricultural practices in sub-Saharan Africa facing increasing climatic challenges.

Exploring CDF gene family in wild potato under salinity stress unveils promising candidates for developing climate-resilient crops

The DNA-binding with one finger (Dof) gene family is a class of plant-specific transcription factors involved in diverse biological processes, including response to biotic and abiotic stresses. Members of this family have been reported in the cultivated potato Solanum tuberosum, but clues to the roles of several Dof genes are still lacking. Potato wild relatives represent a genetic reservoir for breeding as they could provide useful alleles for adaptation to the environment and tolerance to biotic and abiotic stresses. We performed an in silico analysis to identify genes belonging to the Dof family in the wild potato S. commersonii, confirming that the identified Dof genes can be grouped in four classes (A, B, C, D), as reported for cultivated potato. A special focus was dedicated to Cycling Dof Factors (CDFs), which play a crucial role in plant responses to abiotic stresses. Analysis of available RNA-seq data confirmed CDF genes as regulated by stresses and often in a tissue specific manner. To ascertain their involvement in the stress response, S. tuberosum and S. commersonii plantlets growing in vitro were subjected to salt stress (80mM NaCl) for short (2 days) and prolonged (7 days) times. Analysis of phenotypic traits and qRT-PCR expression profiles of target CDF genes in aerial and root tissues showed differences between the two species. In addition, after saline treatment, changes in total phenols, proline, and malondialdehyde suggested a diverse perception of saline stress in S. commersonii vs. S. tuberosum. Overall, this study provided useful clues to the involvement of CDF genes in salt response and promoted the identification of potential candidate genes for further functional studies.

Genome-Scale Identification of Wild Soybean Serine/Arginine-Rich Protein Family Genes and Their Responses to Abiotic Stresses.

Serine/arginine-rich (SR) proteins mostly function as splicing factors for pre-mRNA splicing in spliceosomes and play critical roles in plant development and adaptation to environments. However, detailed study about SR proteins in legume plants is still lacking. In this report, we performed a genome-wide investigation of SR protein genes in wild soybean (Glycine soja) and identified a total of 31 GsSR genes from the wild soybean genome. The analyses of chromosome location and synteny show that the GsSRs are unevenly distributed on 15 chromosomes and are mainly under the purifying selection. The GsSR proteins can be phylogenetically classified into six sub-families and are conserved in evolution. Prediction of protein phosphorylation sites indicates that GsSR proteins are highly phosphorylated proteins. The protein-protein interaction network implies that there exist numerous interactions between GsSR proteins. We experimentally confirmed their physical interactions with the representative SR proteins of spliceosome-associated components such as U1-70K or U2AF35 by yeast two-hybrid assays. In addition, we identified various stress-/hormone-responsive cis-acting elements in the promoter regions of these GsSR genes and verified their expression patterns by RT-qPCR analyses. The results show most GsSR genes are highly expressed in root and stem tissues and are responsive to salt and alkali stresses. Splicing analysis showed that the splicing patterns of GsSRs were in a tissue- and stress-dependent manner. Overall, these results will help us to further investigate the biological functions of leguminous plant SR proteins and shed new light on uncovering the regulatory mechanisms of plant SR proteins in growth, development, and stress responses.

Characterization of the gibberellic oxidase gene SdGA20ox1 in Sophora davidii (Franch.) skeels and interaction protein screening.

Gibberellin 20-oxidases (GA20oxs) are multifunctional enzymes involved in regulating gibberellin (GA) biosynthesis and controlling plant growth. We identified and characterized the GA20ox1 gene in a plant height mutant of Sophora davidii, referred to as SdGA20ox1. This gene was expressed in root, stem, and leaf tissues of the adult S. davidii plant height mutant, with the highest expression observed in the stem. The expression of SdGA20ox1 was regulated by various exogenous hormones. Overexpression of SdGA20ox1 in Arabidopsis resulted in significant elongation of hypocotyl and root length in seedlings, earlier flowering, smaller leaves, reduced leaf chlorophyll content, lighter leaf color, a significant increase in adult plant height, and other phenotypes. Additionally, transgenic plants exhibited a substantial increase in biologically active endogenous GAs (GA1, GA3, and GA4) content, indicating that overexpression of SdGA20ox1 accelerates plant growth and development. Using a yeast two-hybrid (Y2H) screen, we identified two SdGA20ox1-interacting proteins: the ethylene receptor EIN4 (11430582) and the rbcS (11416005) protein. These interactions suggest a potential regulatory mechanism for S. davidii growth. Our findings provide new insights into the role of SdGA20ox1 and its interacting proteins in regulating the growth and development of S. davidii.

Gene markers generating polygenic resistance in melon-Fusarium wilt-FOM1.2 interaction pathosystem.

Developing melon genotypes with resistance to Fusarium oxysporum f. sp. Melonis-(FOM) race1.2 is a major goal in any breeding program. In this study, we identified the role of 11 gene markers that contribute to polygenic resistance during the FOM1.2-melon interaction. qRT-PCR analysis elucidated upregulation of candidate marker genes AMT, DXPR, Fom-2, GLUC, GalS, GRF3, MLO, PRK, RuBlsCo, TLP and WRKY in resistant 'Shante-F1' and 'Khatouni', and susceptible 'Shante-T' and 'Shahabadi' at 7, 14 and 21 days post-inoculation (dpi). We also studied changes in defence-related enzyme activity: chitinase (CHI), β-1,3-glucanase (GLU) and peroxidase (POX) in melon roots. AMT, GLUC and DXPR transcripts were upregulatied in leaf and root tissues of the resistant 'Shante-F1' and 'Shahabadi'. Transcript levels for GalS and GRF3 increased 6.77- and 6.83-fold in roots of 'Shante-F1' at 7 dpi, whereas in PRK, TLP and WRKY theye increased by 7.84-, 5.15- and 12.26-fold at 14 dpi, respectively. However, transcript levels increased by 5.18-fold for Fom-2 and 8.46-fold for MLO at 21 dpi. Also, RBC transcript level peaked at 14 dpi with 4.9-fold increase in leaves of resistant genotypes, whereas AMT increased 2.94-fold at 21 dpi, and GLUC and DXPR increased 7.11- and 2.91-fold at 14 dpi in 'Shante-F', respectively. Defence-related-enzyme activity was also upregulated three-fold in resistant varieties. The dynamic shifts in the melon transcriptome induced by FOM1.2 emphasize that resistance mechanisms are predominantly regulated through signalling pathways involving CHI, GLU, and POX defence response. Surprisingly, the AMT gene, basically resistant to downy mildew, Pseudoperonospora cubensis; GLUC, MLO and PRK resistant to powdery mildew (Sphaerotheca fusca); TLP and WRKY resistant to Phytophthora blight (Phytophthora capsici); and GRF3 and RBC resistant to root knot nematodes (Meloidogyne spp.) were upregulated in resistant genotypes, indicating a dual role of these genes in resistance to more than one disease at a time.

Identification of cotton non-pathogenic fungal agent isolates based on morphological and MALDI-TOF mass spectrometry method

In this study, morphological and MALDI-TOF MS identification and comparison of non-pathogenic fungal species isolated from diseased root, leaf and boll tissues of cotton plants were carried out. For this purpose, surveys were conducted in Bağlar, Sur, Çınar, Bismil, Yenişehir, Ergani, Eğil, Kayapınar and Silvan districts of Diyarbakır province where cotton production is intensive between June and September 2020 and 2021. 209 samples of plants showing typical fungal disease symptoms were collected from 75 different cotton production areas. A total of 171 fungal isolates were obtained by isolation, culture and purification procedures from diseased plant tissues in the samples. The 20 isolates that were negative in the pathogenicity test in the main host were identified and compared by morphological (traditional) and MALDI-TOF MS methods. According to the results, Aspergillus niger, Aspergillus flavus, Aspergillus terreus, Aspergillus fumigatus, Aspergillus minisclerotigenes, Penicillium nalgıovense, Chaetomium globosum, Dichotomopilus funicola, Arthroderma gloria, Pseudogmnoacus pannorum, Tichophyton interdigitale, and Penicillium sp. Penicillium sp. were found to be intensively colonized in different parts of cotton such as leaves, bolls and roots. Again, it was determined that the most common species among the total saprophyte isolates was Aspergillus niger with a high similarity rate.

Single and combined applications of dopamine and 24-epibrassinolide in soybean seedlings under water deficiency: tolerance mechanisms essential to inhibit deleterious effects

Water limitations often cause plants’ physiological, biochemical and morphological disorders, restricting their growth and performance and negatively impacting agricultural yield and global food security. Dopamine (DOP) is an essential water-soluble antioxidant, representing an exciting alternative for use in agriculture, as it maximises plant tolerance under adverse stress conditions. The 24-epibrassionolide (EBR) has the most bioactive function on plant metabolomics, being biodegradable and environmentally friendly. EBR can promote plant tolerance under stress conditions, including water deficiency. Therefore, this study aimed to verify the possible contributions of pre-treatment with DOP and EBR in soybean seedlings subjected to water deficiency, evaluating the responses linked to root anatomy, germination, antioxidant system and biomass accumulation. The single and combined use of growth regulators (DOP and EBR) mitigated the harmful effects caused by water deficiency in seedlings. However, the single use of DOP under the conditions of this research had better results. DOP and EBR positively affected root anatomy, modulating plastic changes in the epidermis tissues, metaxylem and vascular cylinder tissues. Increments in biomass and growth of seedlings exposed to drought and treated with growth regulators can be explained by the intense activities of antioxidant enzymes, maximising redox metabolism and protecting root tissues from oxidative damage.

Effects of wheat-grain moxibustion on autophagy and endoplasmic reticulum stress in rats with cervical spondylotic radiculopathy

To observe the effects of wheat-grain moxibustion on autophagy and endoplasmic reticulum stress (ERS) in the spinal cord and nerve root tissues of rats with cervical spondylotic radiculopathy (CSR), and to explore the potential mechanisms by which wheat-grain moxibustion alleviates neuropathic pain in CSR. Forty-eight SPF-grade SD rats were randomly divided into a sham operation group, a model group, a wheat-grain moxibustion group, and a wheat-grain moxibustion + 3-methyladenine (3MA) group, with 12 rats in each group. The CSR model was established in the model group, the wheat-grain moxibustion group, and the wheat-grain moxibustion + 3MA group using the spinal canal insertion method. From the third day after successful modeling, the wheat-grain moxibustion group received wheat-grain moxibustion at "Dazhui" (GV 14), once daily, six cones each session. The wheat-grain moxibustion + 3MA group received intraperitoneal injection of 3MA (2.5 mg/kg), followed by the same wheat-grain moxibustion intervention as the wheat-grain moxibustion group. Interventions were performed once daily for seven consecutive days. The gait disturbance scores and peripheral nerve mechanical pain thresholds were observed before and after the intervention. Western blot was used to detect the expression of ERS apoptosis factors C/EBP-homologous protein (CHOP) and Caspase-12, as well as autophagy substrate P62 in spinal cord and nerve root tissues. Transmission electron microscopy was used to observe autophagosomes and cellular ultrastructure in spinal cord and nerve root tissues. After modeling, compared with the sham operation group, gait disturbance scores were increased (P<0.05) and peripheral nerve mechanical pain thresholds were decreased (P<0.05) in the model group, the wheat-grain moxibustion group, and the wheat-grain moxibustion + 3MA group. After intervention, compared with the sham operation group, gait disturbance scores were increased (P<0.05) and peripheral nerve mechanical pain thresholds were decreased (P<0.05) in the model group; compared with the model group, gait disturbance score was decreased (P<0.05) and peripheral nerve mechanical pain threshold was increased (P<0.05) in the wheat-grain moxibustion and the wheat-grain moxibustion + 3MA group; compared with the wheat-grain moxibustion + 3MA group, gait disturbance score was decreased (P<0.05) and peripheral nerve mechanical pain threshold was increased (P<0.05) in the wheat-grain moxibustion group. Compared with the sham operation group, the expression of CHOP and Caspase-12 proteins in spinal cord and nerve root tissues was increased in the model group (P<0.05); compared with the model group and the wheat-grain moxibustion + 3MA group, the expression of CHOP, Caspase-12, and P62 proteins in spinal cord and nerve root tissues was decreased in the wheat-grain moxibustion group (P<0.05). Compared with the model group and the wheat-grain moxibustion + 3MA group, the number of autophagosomes in spinal cord and nerve root tissues was increased in the wheat-grain moxibustion group, and the cellular ultrastructure was clear and intact, similar to the sham operation group. Wheat-grain moxibustion at "Dazhui" (GV 14) could effectively alleviate neuropathic pain in CSR model rats. The analgesic mechanism may be related to promoting autophagy, inhibiting ERS, reducing ERS-mediated apoptosis, and repairing damaged nerves.

Acremochlorin S and other prenylated chlorophenol antimicrobial metabolites from the fungus Acremonium sp. Strain MNA-F-1

Chemical prospection for the mycelial extract of the fungus Acremonium sp. Strain MNA-F-1, derived from the inner tissue of anise roots (Pimpnella anisum L., family Apiaceae), led to the isolation and characterization of one previously undescribed natural product, acremochlorin S (1), together with five related derivatives (2–6) and an alkaloidal metabolite, ilicicolin H (7). Structure elucidation of the isolated compounds was determined through comprehensive 1D/2D NMR spectroscopic analyses and HR-ESI-MS measurements. The absolute configuration of acremochlorin S (1) was concluded based on the comparison of its experimental and calculated electronic circular dichroism (ECD) spectra implementing Time-dependent density functional theory (TDDFT). All isolated compounds were assessed for their antibacterial activity against Staphylococcus aureus, Escherichia coli and Mycobacterium tuberculosis, where several compounds revealed potent activities against tested Gram-positive strains.