Control Of Plant Diseases Research Articles

Edeine B1 produced by Brevibacillus brevis reduces the virulence of a plant pathogenic fungus by inhibiting mitochondrial respiration.

Plant pathogenic fungi cause serious diseases, which result in the loss of crop yields and reduce the quality of crops worldwide. To counteract the escalating risks of chemical fungicides, interest in biological control agents to manage plant diseases has significantly increased. In this study, we comprehensively screened microbial culture filtrates using a yeast screening system to find microbes exhibiting respiratory inhibition activity. Consequently, we found a soil-borne microbe Brevibacillus brevis HK544 strain exhibiting a respiration inhibitory activity and identified edeine B1 (EB1) from the culture filtrate of HK544 as the active compound of the respiration inhibition activity. Furthermore, against a plant pathogenic fungus Fusarium graminearum, our results showed that EB1 has effects on multiple aspects of respiration with the downregulation of most of the mitochondrial-related genes based on transcriptome analysis, differential EB1-sensitivity from targeted mutagenesis, and the synergistic effects of EB1 with electron transport chain complex inhibitors. With the promising plant disease control efficacy of B. brevis HK544 producing EB1, our results suggest that B. brevis HK544 has potential as a biocontrol agent for Fusarium head blight.IMPORTANCEAs a necrotrophic fungus, Fusarium graminearum is a highly destructive pathogen causing severe diseases in cereal crops and mycotoxin contamination in grains. Although chemical control is considered the primary approach to control plant disease caused by F. graminearum, fungicide-resistant strains have been detected in the field after long-term continuous application of fungicides. Moreover, applying chemical fungicides that trigger mycotoxin biosynthesis is a great concern for many researchers. Biocontrol of Fusarium head blight (FHB) by biological control agents (BCAs) represents an alternative approach and could be used as part of the integrated management of FHB and mycotoxin production. The most extensive studies on bacterial BCAs-fungal communications in agroecosystems have focused on antibiosis. Although many BCAs in agricultural ecology have already been used for fungal disease control, the molecular mechanisms of antibiotics produced by BCAs remain to be elucidated. Here, we found a potential BCA (Brevibacillus brevis HK544) with a strong antifungal activity based on the respiration inhibition activity with its active compound edeine B1 (EB1). Furthermore, our results showed that EB1 secreted by HK544 suppresses the expression of the mitochondria-related genes of F. graminearum, subsequently suppressing fungal development and the virulence of F. graminearum. In addition, EB1 exhibited a synergism with complex I inhibitors such as rotenone and fenazaquin. Our work extends our understanding of how B. brevis HK544 exhibits antifungal activity and suggests that the B. brevis HK544 strain could be a valuable source for developing new crop protectants to control F. graminearum.

Hormesis in Pathogenic and Biocontrol Fungi: From Inhibition to Stimulation

Hormesis, a biphasic response where low doses of stressors stimulate growth and high doses inhibit it, has significant implications for agricultural chemical use. This review explores the impact of low-dose fungicides or pesticides on pathogenic and biocontrol fungi. This study highlights how sublethal dose exposure can enhance growth and virulence of fungal pathogens, while also potentially increasing their stress tolerance at higher doses. This phenomenon complicates fungicide resistance management strategies. The review focuses on specific fungicides such as dimethachlone, prochloraz, carbendazim, and others, and their hormetic effects on fungal pathogens. Furthermore, the effects of low-dose pesticides and fungicides on beneficial fungi like entomopathogenic and arbuscular mycorrhizal fungi (AMF) are discussed. Here, low-dose exposure can stimulate the germination of entomopathogenic fungal conidia and enhance AMF root colonization and phosphorus uptake. However, hormesis can have trade-offs, potentially leading to unforeseen consequences for the organism. A thorough understanding of hormesis and dose-dependent fungicide effects is crucial for optimizing disease management and agricultural practices. This knowledge can inform strategies to minimize pathogen resistance and promote sustainable approaches. Implementing integrated disease management that combines fungicides with different modes of action alongside other control methods can be effective. Careful consideration of fungicide doses and potential hormesis effects is paramount for ensuring sustainable plant disease control and food security.

Quick Plant Sample Preparation Methods Using a Micro-Homogenizer for the Detection of Multiple Citrus Pathogens

Effective pathogen detection is essential for plant disease control. However, plant sample preparation for downstream assays, such as quantitative polymerase chain reaction (qPCR), is challenging to perform outside of a laboratory. This paper reports two sample preparation methods featuring chemical and mechanical lysis and nucleic acid extraction using a micro-homogenizer, followed by serial dilution or nucleic acid purification with a paper disk before assay. Five minutes of lysis and extraction resulted in DNA and RNA yields of up to 76.5% and 63.3%, respectively, compared to mortar and pestle controls. Crude lysates were unsuitable for direct use in qPCR assays; however, serial dilution or quick wash using chromatography paper rendered samples ready for such assays. Additionally, the nucleic acids stored on paper disks under various storage conditions remained stable for one month. These methods can facilitate the in-field preparation of citrus samples and allow for both onsite and mail-in diagnostics for growers.

Biological Control of Root Rot of Strawberry by Bacillus amyloliquefaciens Strains CMS5 and CMR12.

Strawberry root rot caused by Fusarium solani is one of the main diseases of strawberries and significantly impacts the yield and quality of strawberry fruit. Biological control is becoming an alternative method for the control of plant diseases to replace or decrease the application of traditional chemical fungicides. To obtain antagonistic bacteria with a high biocontrol effect on strawberry root rot, over 72 rhizosphere bacteria were isolated from the strawberry rhizosphere soil and screened for their antifungal activity against F. solani by dual culture assay. Among them, strains CMS5 and CMR12 showed the strongest inhibitory activity against F. solani (inhibition rate 57.78% and 65.93%, respectively) and exhibited broad-spectrum antifungal activity. According to the phylogenetic tree based on 16S rDNA and gyrB genes, CMS5 and CMR12 were identified as Bacillus amyloliquefaciens. Lipopeptide genes involved in surfactin, iturin, and fengycin biosynthesis were detected in the DNA genomes of CMS5 and CMR12 by PCR amplification. The genes related to the three major lipopeptide metabolites existed in the DNA genome of strains CMS5 and CMR12, and the lipopeptides could inhibit the mycelial growth of F. solani and resulted in distorted hyphae. The inhibitory rates of lipopeptides of CMS5 and CMR12 on the spore germination of F. solani were 61.00% and 42.67%, respectively. The plant-growth-promoting (PGP) traits in vitro screening showed that CMS5 and CMR12 have the ability to fix nitrogen and secreted indoleacetic acid (IAA). In the potting test, the control efficiency of CMS5, CMR12 and CMS5+CMR12 against strawberry root rot were 65.3%, 67.94% and 88.00%, respectively. Furthermore, CMS5 and CMR12 enhanced the resistance of strawberry to F. solani by increasing the activities of defense enzymes MDA, CAT and SOD. Moreover, CMS5 and CMR12 significantly promoted the growth of strawberry seedlings such as root length, seedling length and seedling fresh weight. This study revealed that B. amyloliquefaciens CMS5 and CMR12 have high potential to be used as biocontrol agents to control strawberry root rot.

Application of coffee pulp-derived pectins as a novel coating spray to mitigate Paramyrothecium breviseta, an etiological agent inducing leaf spot disease in coffee

Coffee pulp is a significant byproduct of wet processing and poses ecological risks by contributing to soil acidification and diminished fertility in local ecosystems. Despite its potential environmental impact, coffee pulp is rich in various components, including valuable polysaccharides. This study focuses on extracting pectin from coffee pulp using HCl/KCl and ammonium oxalate. The total yield achieved was approximately 11 %, encompassing distinct types of pectins: Acidic coffee pulp pectin (ACPP) and basidic coffee pulp pectin (BCPP), which represent high and low methoxylate forms, respectively. The fabrication of the pectin (1 %) coating agent was accomplished by combining it with chitosan to form a polyelectrolyte complex (1 %) in a ratio of 10:1. The coffee pulp polyphenols fraction (CPPF), was embedded in the agent at 0.5 g/mL and characterised for inhibiting Paramyrothecium breviseta, a pathogen causing leaf spot in coffee. Experimental results demonstrated that the coating spray, derived from coated ACPP and coated CPPF exhibited the highest efficacy in inhibiting P. breviseta at distances of 0.00 and 1.70 cm on day 16, respectively. This efficacy was significantly different from both the negative control (7.40 cm) and the positive control (4.30 cm). This research highlights the potential of utilising coffee pulp as a valuable resource for pectin extraction and underscores the effectiveness of a formulated coating spray in mitigating the impact of the leaf spot-causing pathogen. The findings contribute to sustainable practices in coffee waste management while presenting a promising approach for plant disease control in coffee cultivation.

Improving the quality of organic fertilizer by utilizing local microorganisms (LMO) of cassava tapai

Local Micro Organism Solution (LMO Solution) is a fermentation solution made from various locally available resources, both plants and animals. The LMO solution contains micro and macronutrients and bacteria that have the potential to decompose organic matter in the soil, stimulate plant growth, and act as a pest and plant disease control agent. It is easy to obtain and makes it possible to increase farmers’ desire to process agricultural waste. This research aims to determine the quality of organic fertilizer from livestock manure by utilizing local microorganisms (LMO) in cassava. This research was carried out from March 2023 to December 2023. The research was carried out at the Soil Laboratory of Hasanuddin University and the Greenhouse of the Faculty of Agriculture and Forestry, West Sulawesi University. The experimental design used in this planting test was a Completely Randomized Design (CRD), consisting of four LMO dose treatments, with each treatment carried out three times. The results of the research showed that the planting media provided by LMO tapai cassava had a significant effect on increasing the availability of the nutrients Nitrogen (N) and Phosphorus (P). The treatment regimen involving a dose of 240 ml (M3) showed the highest average values ​​for nutrient content, specifically 0.25% for Nitrogen (N) and 13.75 ppm for Phosphorus (P2O5). Providing cassava tapai LMO in the planting medium had a significant effect on the average height of spinach plants at the observation time of 10 day after planting (DAT) and the average leaf weight. The M3 treatment showed the highest average value of plant height at 10 DAT of 7.17 cm and leaf weight of 0.73 g.

Characterization of Two Novel Single-Stranded RNA Viruses from Agroathelia rolfsii, the Causal Agent of Peanut Stem Rot.

Peanut stem rot is a soil-borne disease caused by Agroathelia rolfsii. It occurs widely and seriously affects the peanut yield in most peanut-producing areas. The mycoviruses that induce the hypovirulence of some plant pathogenic fungi are potential resources for the biological control of fungal diseases in plants. Thus far, few mycoviruses have been found in A. rolfsii. In this study, two mitoviruses, namely, Agroathelia rolfsii mitovirus 1 (ArMV1) and Agroathelia rolfsii mitovirus 2 (ArMV2), were identified from the weakly virulent A. rolfsii strain GP3-1, and they were also found in other A. rolfsii isolates. High amounts of ArMV1 and ArMV2in the mycelium could reduce the virulence of A. rolfsii strains. This is the first report on the existence of mitoviruses in A. rolfsii. The results of this study may provide insights into the classification and evolution of mitoviruses in A. rolfsii and enable the exploration of the use of mycoviruses as biocontrol agents for the control of peanut stem rot.

The Growth-Promoting and Colonization of the Pine Endophytic Pseudomonas abietaniphila for Pine Wilt Disease Control.

In this study, we focused on evaluating the impact of Pseudomonas abietaniphila BHJ04 on the growth of Pinus massoniana seedlings and its biocontrol efficacy against pine wilt disease (PWD). Additionally, the colonization dynamics of P. abietaniphila BHJ04 on P. massoniana were examined. The growth promotion experiment showed that P. abietaniphila BHJ04 significantly promoted the growth of the branches and roots of P. massoniana. Pot control experiments indicated that strain BHJ04 significantly inhibited the spread of PWD. There were significant changes in the expression of several genes related to pine wood nematode defense in P. massoniana, including chitinase, nicotinamide synthetase, and triangular tetrapeptide-like superfamily protein isoform 9. Furthermore, our results revealed significant upregulation of genes associated with the water stress response (dehydration-responsive proteins), genetic material replication (DNA/RNA polymerase superfamily proteins), cell wall hydrolase, and detoxification (cytochrome P450 and cytochrome P450 monooxygenase superfamily genes) in the self-regulation of P. massoniana. Colonization experiments demonstrated that strain BHJ04 can colonize the roots, shoots, and leaves of P. massoniana, and the colonization amount on the leaves was the greatest, reaching 160,000 on the 15th day. However, colonization of the stems lasted longer, with the highest level of colonization observed after 45 d. This study provides a preliminary exploration of the growth-promoting and disease-preventing mechanisms of P. abietaniphila BHJ04 and its ability to colonize pines, thus providing a new biocontrol microbial resource for the biological control of plant diseases.

Essential Oils for Managing Anthracnose in Mango (Mangifera indica): Laboratory Results Do Not Translate into Field Efficacy.

Essential oil-based products with broad plant disease control claims are commercially available and may be a practical alternative to copper fungicides for crop protection in organic mango orchards. We evaluated the disease control efficacy and crop safety of thyme oil, savory oil, and tree tea oil through replicated in vitro, in vivo (detached leaf and potted trees), and field assays. Three Colletotrichum species associated with mango anthracnose were tested in vitro, whereas only C. siamense was used for in vivo assays. Within the range of concentrations tested in vitro (62.5 to 2,000 μl active ingredient [a.i.]/liter), thyme and savory oil displayed fungicidal activity, whereas no fungistatic or fungicidal activity was observed with tea tree oil. In the in vivo assays, none of the treatments based on a preventive application rate of thyme (1,150 μl a.i./liter), savory (2,000 μl a.i./liter), or tea tree oil (342 μl a.i./liter) were effective in preventing the development of anthracnose on wounded and artificially inoculated leaves. Although field applications of thyme or tea tree oil did not result in phytotoxicity or negative impacts on fruit yield, they were ineffective in reducing the incidence and severity of naturally occurring anthracnose. Applications of copper hydroxide approved for organic agriculture were effective in controlling anthracnose in the field, and no added benefits were found by premixing this compound with thyme oil. Results indicate that essential oil products based on thyme or tea tree oil are inefficient at controlling anthracnose in mangoes.

The rice E3 ubiquitin ligase-transcription factor module targets two trypsin inhibitors to enhance broad-spectrum disease resistance

Broad-spectrum disease resistance (BSR) is crucial for controlling plant diseases and relies on immune signals that are subject to transcriptional and post-translational regulation. How plants integrate and coordinate these signals remains unclear. We show here that the rice really interesting new gene (RING)-type E3 ubiquitin ligase OsRING113 targets APIP5, a negative regulator of plant immunity and programmed cell death (PCD), for 26S proteasomal degradation. The osring113 mutants in Nipponbare exhibited decreased BSR, while the overexpressing OsRING113 plants showed enhanced BSR against Magnaporthe oryzae (M.oryzae) and Xanthomonas oryzae pv. oryzae (Xoo). Furthermore, APIP5 directly suppressed the transcription of the Bowman-Birk trypsin inhibitor genes OsBBTI5 and AvrPiz-t-interacting protein 4 (APIP4). Overexpression of these two genes, which are partially required for APIP5-mediated PCD and disease resistance, conferred BSR. OsBBTI5 and APIP4 associated with and stabilized the pathogenesis-related protein OsPR1aL, which promotes M.oryzae resistance. Our results identify an immune module with integrated and coordinated hierarchical regulations that confer BSR in plants.

Study on droplet deposition characteristics and application of small and medium crown garden plants sprayed by UAV sprayer.

The Unmanned Aerial Vehicle (UAV) sprayer has the advantages of high work efficiency, simple operation, and high safety factor, and has broad application prospects UAV sprayer are widely used in the agricultural field, and the application of UAV sprayer spraying technology in agriculture has provided convenience and increased profits for farmers, and has also become a research hotspot in the field of agriculture. In recent years, although research has been conducted on the feasibility and application effects of UAV sprayer spraying crown shaped plants, there have been no experiments or studies in the field of garden plants. This experiment conducted a droplet deposition experiment of UAV sprayer spraying garden plants, exploring the droplet deposition effect of UAV sprayer in the field of garden plants, and conducting experiments on the influence of spray volume and nozzle type on droplet deposition. The experimental results showed that the canopy performance of small and medium-sized garden plants was better at a flight altitude of 1.5m, a spray volume of 180L/hm2, and a flight speed of 2m/s. Reducing flight altitude, increasing spray volume, and reducing flight speed can improve the distribution of droplets in the canopy. This experiment lays the foundation for the application of UAV sprayer for the prevention and control of pests and diseases in garden plants, as well as for the application of growth regulators, and provides a basis for further innovative research in the field of garden plant application technology.

Combined control of plant diseases by Bacillus subtilis SL44 and Enterobacter hormaechei Wu15

Co-incubation of plant growth promoting rhizobacteria (PGPRs) have been proposed as a potential alternative to pesticides for controlling fungal pathogens in crops, but their synergism mechanisms are not yet fully understood. In this study, combined use of Bacillus subtilis SL44 and Enterobacter hormaechei Wu15 could decrease the density of Colletotrichum gloeosporioides and Rhizoctonia solani and enhance the growth of beneficial bacteria on the mycelial surface, thereby mitigating disease severity. Meanwhile, PGPR application led to a reorganization of the rhizosphere microbial community through modulating its metabolites, such as extracellular polymeric substances and chitinase. These metabolites demonstrated positive effects on attracting and enhancing conventional periphery bacteria, inhibiting fungal pathogens and promoting soil health effectively. The improvement in the microbial community structure altered the trophic mode of soil fungal communities, effectively decreasing the proportion of saprotrophic soil and reducing fungal plant diseases. Certain combinations of PGPR have the potential to serve as precise instruments for managing plant pathogens.

Boscalid + Pyraclotrobin Resistance and Expression of Succinate Dehyrogenase Genes (sdhA and sdhB) in Chestnut Blight Fungus Cryphonectria parasitica

Sweet chestnut, Castanea sativa Mill., is a significant species in Türkiye. The tree has been encountered with numerous diseases. Chestnut blight, caused by Cryphonectria parasitica (Murrill) M. E. Barr, is one of the most common diseases having spread to every chestnut-growing region. In this study, the effects of Bellis® (25.2% Boscalid + 12.8% Pyraclotrobin), a fungicide commonly used in plant disease control, were evaluated at different doses (10 ppm and 50 ppm) against the chestnut blight agent C. parasitica, which had not been previously studied for its effects in vitro. The isolates included two virulent strains (Cp1_2023, Cp2_2023) and two hypovirulent strains (Cp7_2023, Cp9_2023). The effects of Boscalid + Pyraclotrobin on the mycelial growth of the pathogenic fungus were determined for the first time in vitro, and these effects were detected at the sdhA and sdhB genes expression level. The results showed that the mycelial growth and pathogenicity of C. parasitica isolates in the fungicide-treated medium were consistent with the gene expression profile. Specifically, the virulent Cp1_2023 isolate exhibited higher mycelial growth, pathogenicity, and gene expression levels compared to the other isolate. In conclusion, it is recommended to conduct more detailed studies before using fungicides and to employ them in controlled environments.

Breeding for Resistance against Pest and Diseases in Tomatoes: A Review

Diseases and pests have a substantial effect on tomato production, greatly affecting both the quantity and quality of this crucial vegetable crop. Although fungicides and insecticides have been important in controlling plant diseases and pests, their excessive usage raises significant environmental issues. Vegetable breeders are increasingly concentrating on developing cultivars with natural tolerance to biotic stresses to promote sustainability and environmental friendliness. The change in focus is intended to cultivate tomato cultivars with inherent resistance to diseases and pests, hence decreasing the need for chemical treatments. Advancements in creating high-yielding genetically resistant tomato cultivars are a result of detailed study on the genetic basis of pest and disease resistance in tomato crops, as well as the complex interactions between the host plant and pathogens. For effective breeding programs and pre-breeding activities, scientists and breeders must have access to sources of resistance and a thorough grasp of the genetic complexities involved. This requires examining the genetic composition of both the tomato plants and the different infections that are impacting them. Breeders may generate tomato cultivars with strong resistance to common diseases and pests by using the inherent defensive mechanisms found in certain tomato types via selective crossing. Continuing to study how hosts and pathogens interact and the molecular processes involved in resistance is crucial. This information offers vital insights on how to improve and expand resistance, leading to the creation of cultivars with long-lasting and wide-ranging resistance. Currently, the emphasis on breeding is a proactive and sustainable strategy for transfer of resistances in high yielding tomato cultivars. Researchers aim to develop tomato cultivars that provide high yield and demonstrate tolerance to changing disease and pest stresses by integrating genetic knowledge with sophisticated breeding methods. This comprehensive method protects tomato crops and encourages environmental sustainability by decreasing the need on chemical inputs in agriculture.

Antibacterial activity of high surface area zinc oxide nanoparticles for controlling black rot disease of Chinese kale

AbstractZinc oxide nanoparticles (ZnO NPs) are inorganic compounds listed as “generally recognized as safe” (GRAS) materials and have been used in plant production as well as for plant disease control. This study investigated the antibacterial efficacy of ZnO NPs with various surface areas against Xanthomonas campestris pv. campestris, assessed the effectiveness of ZnO NPs in controlling black rot disease in Chinese kale, and examined the influence of ZnO NPs application on soil bacterial communities. The results showed that ZnO NPs with high surface area effectively inhibited X. campestris pv. campestris by restraining growth and causing cell damage. Seed treatment and foliar spray application of high surface area ZnO NPs at 250 μg/mL significantly reduced the disease severity of black rot. Furthermore, in the greenhouse experiment, the soil bacterial communities in the treatment of plants applied with ZnO NPs did not differ from those in soil of nontreated plants. Therefore, ZnO NPs have the potential to serve as an alternative substance for plant disease management.

Pan-Genome Analysis and Secondary Metabolic Pathway Mining of Biocontrol Bacterium Brevibacillus brevis

Brevibacillus brevis is one of the most common biocontrol strains with broad applications in the prevention and control of plant diseases and insect pests. In order to deepen our understanding of B. brevis genomes, describe their characteristics comprehensively, and mine secondary metabolites, we retrieved the genomic sequences of nine B. brevis strains that had been assembled into complete genomes from the NCBI database. These genomic sequences were analyzed using phylogenetic analysis software, pan-genome analysis software, and secondary metabolite mining software. Results revealed that the genome size of B. brevis strains ranged from 6.16 to 6.73 Mb, with GC content ranging from 47.0% to 54.0%. Phylogenetic analysis classified the nine B. brevis strains into three branches. The analyses of ANI and dDDH showed that B. brevis NEB573 had the potential to become a new species of Brevibacillus and needed further research in the future. The pan-genome analysis identified 10032 gene families, including 3257 core gene families, 3112 accessory gene families, and 3663 unique gene families. In addition, 123 secondary metabolite biosynthetic gene clusters of 20 classes were identified in the genomes of nine B. brevis strains. The major types of biosynthetic gene clusters were non-ribosomal peptide synthase (NRPS) and transAT polyketide synthase (transAT-PKS). Furthermore, a large number of untapped secondary metabolites were identified in B. brevis. In summary, this study elucidated the pan-genome characteristics of the biocontrol bacterium B. brevis and identified its secondary metabolites, providing valuable insights for its further development and utilization.

Alternaria in berry: Effects on its quality, pathogenic mechanisms and potential control strategies

AbstractIn recent years, the production and demand of berries in the world have gradually increased, but the infection of fungal pathogens has become one of the important factors restricting the production and sales of fresh berries. It has been found that Alternaria can cause a variety of plant diseases and fruit rot worldwide. This review introduces the effect of Alternaria infection on berry quality, including physical, chemical and physiological aspects, and discusses the possible infection mechanisms. In addition, Alternaria produces toxins during infections and seriously threatens the safety of berries and consumer health. Therefore, the prevention and control measures of Alternaria are systematically summarized. This review provides the basis for further optimization of postharvest preservation technology and fruit quality, to prolong the shelf life of berries. We can realistically expect to control plant diseases with increasing efficiency, which is conducive to improving the quality and safety of postharvest berry fruits.

Calcium signaling: Unveiling its role in disease control in plants

<p>Calcium signaling is a fundamental regulatory mechanism in plants, governing a myriad of physiological processes crucial for growth, development, and responses to environmental stimuli, including biotic stresses such as pathogen attack. Over the past decades, research into the intricate network of calcium signaling pathways has revealed its pivotal role in orchestrating plant defense mechanisms against a diverse array of pathogens. This review comprehensively examines the multifaceted roles of calcium ions in modulating plant immune responses, elucidating the molecular mechanisms underlying calcium-mediated signal transduction and its integration with other defense signaling pathways. We delve into the intricate crosstalk between calcium signaling and various hormonal pathways, reactive oxygen species (ROS) signaling, and secondary metabolite biosynthesis, highlighting the interconnectedness of these regulatory networks in shaping plant defense strategies. Furthermore, we explore the potential applications of calcium-based strategies for sustainable disease management in agriculture, including the use of calcium channel blockers, calcium chelators, and calcium-rich compounds as novel antimicrobial agents and priming agents for enhancing plant immunity. Challenges and future directions in the field are also discussed, aiming to advance our understanding of calcium signaling in plant-pathogen interactions and harness its potential for developing innovative approaches to combat plant diseases and ensure global food security. This review provides a comprehensive overview of the current state of knowledge regarding calcium signaling in plant disease control, offering valuable insights and perspectives for future research endeavors in this rapidly evolving field.<strong></strong></p>

Synthesis and Antifungal Activity of Coumarin Derivatives Containing Hydrazone Moiety.

Plant disease control mainly relies on pesticides. In this study, a series of coumarin derivatives containing hydrazone moiety were designed and synthesized. The synthesized compounds were characterized and used to evaluate the antifungal activity against four pathogens, Botrytis cinerea, Alternaria solani, Fusarium oxysporum, and Alternaria alternata. The results showed that the inhibition rate of some compounds at 100 μg/mL in 96 hours reached around 70 % against A. alternata, higher than that of the positive control. The corresponding EC50 values were found at around 30 μg/mL. Finally, the compound 3 b was screened out with the lowest EC50 value (19.49 μg/mL). The analysis of SEM and TEM confirmed that the compound 3 b can obviously damage the morphological structure of hyphae, resulting in the depletion of the cells by the destruction of morphological matrix and leakage of contents. RNA sequencing showed that compounds 3 b mainly affected the pentose phosphate pathway, which caused to destroy the layer of mitochondrial structure. Molecular docking showed that compounds 3 b fitted the binding pocket of yeast transketolase and interacted with lysine at the hydrazone structure. Our results suggested that the introduction of hydrazone was an effective strategy for the design of novel bioactive compounds.

Liebig review: The role of mineral nutrients in the development of Pseudomonas syringae diseases—Lessons learned and implications for disease control in woody plants

AbstractBackgroundThe plant pathogen Pseudomonas syringae (Ps) causes diseases in a broad range of hosts including important cash crops from several climate zones. In particular for woody crops, effective and environmentally friendly disease control strategies are not available. Although there is increasing evidence of a link between plant nutritional status and disease susceptibility, optimization of plant nutrition is often neglected in efforts to control Ps diseases. This review brings current knowledge on this topic together with the aim of facilitating the development of treatment recommendations in specific contexts.Literature reviewThe article consists of three parts. First, we compiled data on the impact of mineral nutrients on Ps disease severity in woody and herbaceous species. Next, we discuss how nutrients may be related to plant defense and/or Ps virulence. Last, we consider these findings in the context of woody hosts and give suggestions for future research.ConclusionsWe encourage a research focus on typical nutrient imbalances (deficiencies and surpluses) in specific orchard regions; testing the role of foliar fertilizers in spring (the period of highest infection risk); analyses of the interaction between nutrient supply and the microbiome in the phyllosphere; investigating the interaction between nutrient supply and other control measures, and the impact of nutrient supply on Ps diseases in the presence of other stress factors.