Enhance Plant Health Research Articles

Application of Internet of Things (IoT) on Monitoring EC and pH Values for Fertigation System

This paper introduces a novel Internet of Things (IoT) based fertigation control system designed to enhance traditional agricultural practices in Malaysia, particularly in rural areas. The system integrates a fertigation approach, combining fertilization and irrigation, with smart devices and a NodeMCU ESP32 microcontroller to automate the tracking of data from liquid fertilizer mixtures. By utilizing EC and pH sensors, the system accurately monitors the nutrient concentration and pH levels of the fertilizer mix, with data displayed on an IoT platform for real-time observation and control. This approach mitigates common issues such as overfertilization and inefficient nutrient use, offering significant improvements over manual data collection methods. The system's performance was validated, showing successful monitoring and control of the fertilization process, leading to enhanced plant health and crop quality. Key findings indicate that the system's integration with IoT technology provides a more efficient, automated solution for managing fertilizer applications, reducing labor and time while ensuring optimal plant nutrient levels. The study also highlights the potential for future development, including the integration of additional sensors and advanced data analytics to optimize fertigation practices further. The implementation of this IoT-based system represents a significant advancement towards sustainable agriculture, offering practical benefits for Malaysian farmers and setting a foundation for further innovation in fertigation technology.

Exploring nonanol from Bacillus velezensis (YEBBR6) for root-knot nematode management in bananas: Integrating experimental and computational approaches

Nematode infestations pose a severe threat to global banana production, leading to substantial yield losses and economic damage. Among these, the root-knot nematode Meloidogyne incognita is particularly detrimental, causing root galls that severely impair water and nutrient uptake, leading to stunted growth, reduced fruit quality, and significant economic losses for farmers. In the face of increasing agricultural challenges, bacterial endophytes have emerged as essential tools for sustainable agriculture, offering ecofriendly solutions to enhance plant health and manage pests. The present study aims to identify and characterise biomolecules from bacterial endophyte Bacillus velezensis (YEBBR6) with potential nematicidal properties against root-knot nematode Meloidogyne incognita infecting banana. The analysis of volatile and non-volatile organic compounds (VOCs/NVOCs) from the inhibition zone during the ditrophic interaction between B. velezensis (YEBBR6) and Fusarium oxysporum f.sp. cubense (Foc) revealed the presence of several distinctive biomolecules with antifungal and antimicrobial properties. These compounds included linoelaedic acid, nonanol, acetylvaleryl, 5–hydroxyl methyl furfural, clindamycin, allobarbital, 3-thiazolidine carboxamide, azulene, aminomorpholine, procyclidine, campholic acid, 3 amino-4 hydroxy phenyl sulfone, 3–deoxy mannoic lactone, hexadecanoic acid, oleic acid, and dihydroacridine. The in-silico analysis revealed that nonanol, exhibited strong binding efficacy against M. incognita protein targets, including cytochrome C oxidase subunit 1, calreticulin, neuropeptide G-protein coupled receptor, chorismate mutase 1, venom allergen-like proteins, and β-1,4-endoglucanase. Notably, nonanol proved more effective than the commercially used nematicide carbofuran 3G. Molecular dynamics studies further supported the potential of nonanol, and its nematicidal properties were validated through in vitro and pot culture studies. Moreover, nonanol was found to induce the expression of defense-related genes, such as MAPK10, WRKY22, ascorbate peroxidase, catalase, and NADPH oxidase, in banana seedlings, thus enhancing the plant's immune response. These findings highlight the potential of nonanol, derived from B. velezensis (YEBBR6), as a potent and environmentally friendly alternative for controlling nematode infestations in banana cultivation.

An overview of symbiotic and pathogenic interactions at the fungi-plant interface under environmental constraints

The complex and dynamic interactions between fungi and plants constitute a critical arena in ecological science. In this comprehensive review paper, we explore the multifaceted relationships at the fungi-plant interface, encompassing both mutualistic and antagonistic interactions, and the environmental factors influencing these associations. Mutualistic associations, notably mycorrhizal relationships, play a pivotal role in enhancing plant health and ecological balance. On the contrary, fungal diseases pose a significant threat to plant health, agriculture, and natural ecosystems, such as rusts, smuts, powdery mildews, downy mildews, and wilts, which can cause extensive damage and lead to substantial economic losses. Environmental constraints encompassing abiotic and biotic factors are elucidated to understand their role in shaping the fungi-plant interface. Temperature, moisture, and soil conditions, along with the presence of other microbes, herbivores, and competing plants, significantly influence the outcome of these interactions. The interplay between mutualism and antagonism is emphasised as a key determinant of ecosystem health and stability. The implications of these interactions extend to overall ecosystem productivity, agriculture, and conservation efforts. The potential applications of this knowledge in bioremediation, biotechnology, and biocontrol strategies emphasise the importance of adapting to climate change. However, challenges and future directions in this field include the impacts of climate change, emerging fungal pathogens, genomic insights, and the role of the fungi-plant interface in restoration ecology. Hence, this review paper provides a comprehensive overview of fungi-plant interactions, their environmental influences, and their applications in agriculture, conservation, and ecological restoration.

Streptomyces fradiae Mitigates the Impact of Potato Virus Y by Inducing Systemic Resistance in Two Egyptian Potato (Solanum tuberosum L.) Cultivars

In this study, the impact of culture media filtrate of QD3 actinobacterial isolate on two potato cultivars, Spunta and Diamond, infected with potato virus Y (PVY) was investigated. Various parameters, including infection percentage, PVY virus infectivity, disease severity scoring, PVY optical density, photosynthetic and defense-related biochemical markers, enzymatic profiling, phenolic compounds, proline content, salicylic acid levels, and growth and yield parameters, were assessed to elucidate the potential of the QD3 actinobacterial isolate culture filtrate in mitigating PVY-induced damage. The physiological and biochemical characteristics of the QD3 actinobacterial isolate, including its salinity tolerance, pH preferences, and metabolic traits, were investigated. Molecular identification via 16S rRNA gene sequencing confirmed its classification as Streptomyces fradiae QD3, and it was deposited in GenBank with the gene accession number MN160630. Distinct responses between Spunta and Diamond cultivars, with Spunta displaying greater resistance to PVY infection. Notably, pre-infection foliar application of the QD3 filtrate significantly reduced disease symptoms and virus infection in both cultivars. For post-PVY infection, the QD3 filtrate effectively mitigated disease severity and the PVY optical density. Furthermore, the QD3 filtrate positively influenced photosynthetic pigments, enzymatic antioxidant activities, and key biochemical components associated with plant defense mechanisms. Gas chromatography‒mass spectrometry (GC‒MS) analysis revealed palmitic acid (hexadecanoic acid, methyl ester) and oleic acid (9-octadecanoic acid, methyl ester) as the most prominent compounds, with retention times of 23.23 min and 26.41 min, representing 53.27% and 23.25%, respectively, of the total peak area as primary unsaturated fatty acids and demonstrating antiviral effects against plant viruses. Cytotoxicity assays on normal human skin fibroblasts (HSFs) revealed the safety of QD3 metabolites, with low discernible toxicity at high concentrations, reinforcing their potential as safe and effective interventions. The phytotoxicity results indicate that all the seeds presented high germination rates of approximately 95–98%, suggesting that the treatment conditions had no phytotoxic effect on the Brassica oleracea (broccoli) seeds, Lactuca sativa (lettuce) seeds, and Eruca sativa (arugula or rocket) seeds. Overall, the results of this study suggest that the S. fradiae filtrate has promising anti-PVY properties, influencing various physiological, biochemical, and molecular aspects in potato cultivars. These findings provide valuable insights into potential strategies for managing PVY infections in potato crops, emphasizing the importance of Streptomyces-derived interventions in enhancing plant health and crop protection.

Natural Defense: The Inhibitory Effects of Endophytic Bacillus and Xylaria sp. against Rice Pathogens

Aim: Endophytes living inside the plant tissues are known to play a crucial role in the physiology and developmental functioning of host plants. Rice is the major food crop that feeds half of the world population. But pest and diseases lead to drastic yield reduction in rice. Sustainable and eco-friendly disease management strategies are urgently needed to reduce the reliance on chemical pesticides and mitigate the environmental impact of intensive agriculture.The aim of the study was the selection of natural suppressors of the brown spot and sheath blight diseases in rice. In this study, three bacterial endophytes viz., Bacillus subtilis isolate PAL 11, B. altitudins isolate TSL-4 and B. altitudinis isolate KAM-11 and one endophytic fungal isolate Xylaria sp. isolate KTD-2 were tested for their potential to inhibit Bipolaris oryzae and Rhizoctonia solani under in vitro conditions. Methodology: In vitro evaluation of endophytes against two major rice pathogens viz., Rhizoctonia solani and Bipolaris oryzae causing sheath blight and brown leaf spot respectively were tested by dual culture technique. Results: All the tested bacterial and fungal endophytes significantly inhibited both the pathogens under in vitro conditions. Among the bacterial endophytes, B. subtilis isolate PAL-11 exhibited highest inhibition of both the pathogens. The mycelial inhibition of B. oryzae was 56.04 and 74.48 per cent respectively at 5 and 8 days after dual culturing whereas the inhibition of R. solani was 80.31 and 80.22 per cent respectively at 3 and 5 days after dual culturing. The fungal endophyte Xylaria sp. isolate KTD-2 exhibited 63.2 and 67.95 per cent inhibition of mycelial growth of B. oryzae at 5 and 8 days respectively after the pathogen inoculation. The mycelial growth of R. solani was also significantly inhibited (54.95 %) by the fungal endophyte at 5 days after pathogen inoculation. Conclusion: This research highlights the potential role of endophytes in sustainable agriculture and suggests that integrating beneficial microbes into rice disease management strategies could help enhance plant health, increase crop yields, and contribute to global food security.

Production of genetically stable and Odontoglossum ringspot virus-free Cymbidium orchid ‘New True’ plants via meristem-derived protocorm-like body (PLB) subcultures

BackgroundThis study aimed to produce Odontoglossum ringspot virus (ORSV)-free Cymbidium orchid ‘New True’ plants from ORSV-infected mother plants by culturing their meristems and successively repeating subcultures of protocorm-like bodies (PLBs) derived from the meristems.ResultsInitially, ORSV was confirmed as the causative agent of viral symptoms in orchid leaves via reverse transcription-polymerase chain reaction (RT-PCR) analysis. Meristems from infected plants were cultured to generate PLBs, which in sequence were repeatedly subcultured up to four times. RT-PCR and quantitative RT-PCR analyses revealed that while ORSV was undetectable in shoots derived from the first subculture, complete elimination of the virus required at least a second subculture. Genetic analysis using inter-simple sequence repeat markers indicated no somaclonal variation between regenerated plants and the mother plant, suggesting that genetic consistency was maintained.ConclusionOverall, our findings demonstrate that subculturing PLBs for a second time is ideal for producing genetically stable, ORSV-free Cymbidium orchids, thus offering a practical means of generating genetically stable, virus-free plants and enhancing plant health and quality in the orchid industry.

Management of Rhizoctonia blight of groundnut using antagonistic effects of bioagents and organic amendments

Rhizoctonia blight disease caused by Rhizoctonia solani in groundnut crop is one of the most devastating diseases occurring worldwide. The disease affects the morphological and physiological parameters of the crop leading to reduction in pod yield as well as oil yield. The pathogen was isolated locally and identified as Rhizoctonia solani based on molecular characterization. The efficacy of different bioagents in reducing the radial growth of pathogen was tested in vitro and highest mycelia growth inhibition was recorded by Trichoderma asperellum (89.07 %). Among the fungicides tested, 100 % mycelial growth inhibition was observed by use of Carbendazim 50 WP, Tebuconazole 25.9 % EC, Hexaconazole 5 % suspension concentrate (SC) and Tebuconazole 50 % + Trifloxystrobin 25 % water-dispersible granule (WG). Among different organic substances tested in vitro, neem seed cake achieved maximum mycelial growth inhibition of 50.74 % and 54.08 % at 10 % and 20 % concentrations respectively. In the field experiment, treatment with application of neem seed cake to the soil at 500 kg/ha + application of mustard seed cake to the soil at 500 kg/ha + treatment of seeds with Tebuconazole at 1.5 g/kg of seed + treatment of seeds with T. asperellum at 10 g/kg of seed was found to be the best in enhancing plant health, growth promotion and oil yield. The combined treatment of bioagent, fungicide and organic amendment recorded maximum number of branches (14.00), number of leaves (668.33), plant dry weight (64.17 g), 100 pod weight (65.00 g) and oil yield (47.33 %) compared to the control and other treatments along with reduction of the disease (59.61 %). In the physiological parameters study, the same treatment also recorded maximum pigment contents viz. Chlorophyll a (1.843 mg/g), Chlorophyll b (0.555 mg/g), total chlorophyll (2.397 mg/g) and carotenoid content (0.084 mg/g) but with minimum phenol content (1.693 mg/g). Thus, it can be concluded that integration of selective inputs in the combined treatment of Neem seed cake, Mustard seed cake, Tebuconazole and T. asperellum could enhance the plant health, morphological growth and physiological parameters and increased the oil yield in groundnut along with reduction of the disease.

The effects of Pinus sylvestris L. geographical origin on the community and co-occurrence of fungal and bacterial endophytes in a common garden experiment.

This study advances our understanding of how plant ecotype and seasonal changes influence root endophytic communities in Scots pine (Pinus sylvestris). By examining trees from various origins grown in a common garden, it highlights the role of tree origin and season in shaping fungal and bacterial community and co-occurrence networks. Importantly, this research demonstrates that tree origin impacts the composition and interaction networks of root endophytes and depends on the season. The study's findings suggest that root biochemical traits and climatic conditions (e.g., temperature, precipitation) associated with tree origin are crucial in determining the assembly of endophytic communities. This understanding could lead to innovative strategies for enhancing plant health and adaptability across different environments, contributing to forestry and conservation efforts. The research underscores the complexity of plant-microbe interactions and the need for a comprehensive approach to studying them, highlighting the interplay between tree origin and microbial ecology in forest ecosystems.

Coordinated influence of Funneliformis mosseae and different plant growth-promoting bacteria on growth, root functional traits, and nutrient acquisition by maize.

Rhizospheric interactions among plant roots, arbuscular mycorrhizal fungi, and plant growth-promoting bacteria (PGPB) can enhance plant health by promoting nutrient acquisition and stimulating the plant immune system. This pot experiment, conducted in autoclaved soil, explored the synergistic impacts of the arbuscular mycorrhizal fungus Funneliformis mosseae with four individual bacterial strains, viz.: Cronobacter sp. Rz-7, Serratia sp. 5-D, Pseudomonas sp. ER-20 and Stenotrophomonas sp. RI-4A on maize growth, root functional traits, root exudates, root colonization, and nutrient uptake. The comprehensive biochemical characterization of these bacterial strains includes assessments of mineral nutrient solubilization, plant hormone production, and drought tolerance. The results showed that all single and interactive treatments of the mycorrhizal fungus and bacterial strains improved maize growth, as compared with the control (no fungus or PGPB). Among single treatments, the application of the mycorrhizal fungus was more effective than the bacterial strains in stimulating maize growth. Within the bacterial treatments, Serratia sp. 5-D and Pseudomonas sp. ER-20 were more effective in enhancing maize growth than Cronobacter sp. Rz-7 and Stenotrophomonas sp. RI-4A. All bacterial strains were compatible with Funneliformis mosseae to improve root colonization and maize growth. However, the interaction of mycorrhiza and Serratia sp. 5-D (M + 5-D) was the most prominent for maize growth improvement comparatively to all other treatments. We observed that bacterial strains directly enhanced maize growth while indirectly promoting biomass accumulation by facilitating increased mycorrhizal colonization, indicating that these bacteria acted as mycorrhizal helper bacteria.

A Novel Plant-Derived Biopesticide Mitigates Fusarium Root Rot of Angelica sinensis by Modulating the Rhizosphere Microbiome and Root Metabolome.

Fusarium root rot caused by the Fusarium species complex significantly affects the yield and quality of Angelica sinensis, a valuable medicinal herb. Traditional management primarily relies on chemical fungicides, which have led to pathogen resistance, environmental hazards, and concerns regarding public health and the active components in A. sinensis. This study explores the efficacy of a novel plant-derived biopesticide Shi Chuang Zhi Feng Ning (T1; SCZFN), alongside Bacillus subtilis wettable powder (T2) and a chemical fungicide (T3), in controlling root rot and understanding their impacts on the rhizosphere microbial community and root metabolome. Results of the field experiment demonstrated that treatments T1 and T3 achieved control efficiencies of 73.17% and 75.45%, respectively, significantly outperforming T2 (39.99%) and the control. High-throughput sequencing revealed that all treatments altered the diversity and structure of microbial communities, with T1 and T2 reducing the abundance of taxa linked to root rot, such as Muribaculaceae spp., Humicola spp., Fusarium spp., and Mycochlamys spp. Treatment T1 notably enhanced beneficial bacterial taxa, including Acidobacteria spp., Nitrospira spp., and Pedosphaeraceae spp., involved in carbon cycling and plant growth promotion. Metabolomic analysis identified 39, 105, and 45 differentially expressed metabolites (DEMs) across the treatments, demonstrating T1's potential to modulate the root metabolome effectively. Further, a correlation analysis demonstrated a stronger correlation between distinct microorganisms with significant influence and DEMs of T1 treatment compared to other treatments. These findings underscore biopesticide SCZFN's role in enhancing plant health and disease suppression in A. sinensis, providing insights into its biocontrol mechanisms and supporting the development of sustainable disease management strategies in its cultivation.

Rhizobacterial consortium differently affects black leaf spot, physiological, morphological, and productive components in two generations of banana plants

Rhizobacteria's effects on commercial banana plants in different generations remain unclear. In the present field-level investigation, we evaluated the effect of three types (injection, edaphic, and foliar) of applications of a local rhizobacterial consortium on Black leaf spot (BLS), chlorophyll content, morphological components, and fruit production in two generations of commercial banana plants cv. Williams. The rhizobacteria-treated mother and daughter plants received one and two applications, respectively, while the untreated plants constituted the control group. Results of the present investigation indicated that the rhizobacteria differently affect the aerial tissues of different generations of banana plants. Regardless of how the rhizobacteria were applied, they reduced an average of 40 % the BLS incidence on leaves (P ≤ 0.0001) and increased an average 9 % the plant height and pseudostem circumference (P ≤ 0.0001 – P = 0.0475) of mother and daughter plants were observed. However, both morphological variables improved even more in daughter plants edaphically treated with rhizobacteria. Leaf pigments like chlorophyll B (P = 0.0262) and the total content (P = 0.0230) only increased an average of 40 % in daughter plants treated with rhizobacteria. Rhizobacteria edaphic application and injection improved bunch weight (P = 0.0048) and hands per bunch (P ≤ 0.0001) in mother plants. Meanwhile, the edaphic application significantly increased the bunch weight (P = 0.0031), hands per bunch (P = 0.0074), and rachis weight (P = 0.023) by 17% on average in edaphically and foliar-treated mother plants, while the finger length (P = 0.0064) increased by 5% on average. Generally, the morphological and productive components increased much more in daughter plants than in mother. These findings demonstrate the potential of edaphically and foliar rhizobacterial applications to enhance plant health and productivity, providing a sustainable management strategy for banana cultivation.

Field study on the integration of a hydrogen-producing microbiome in restoring Phellinus noxius-affected rhizosphere

At National Kaohsiung University of Science and Technology (NKUST), a mesophilic anaerobic bioreactor system produces a hydrogen-producing microbiome (HMb) containing beneficial bacteria such as Bacillus sp. This HMb, known for degrading cellulose and remediating soil, is being tested in Kaohsiung City, Taiwan, to treat tree root rot caused by Phellinus noxius (P. noxius). The study aims to evaluate HMb's effectiveness in restoring the rhizosphere, enhancing soil health, and increasing tree resistance by assessing soil bioactivity and microbial diversity.Field experiments showed that HMb treatment improved tree health by 24 % at the highest health level but reduced it by 20 % at the next level. Post-treatment soil organic matter (SOM) and total Kjeldahl nitrogen (TKN) levels remained stable, indicating minimal impact on soil fertility. HMb also lowered soil pH in some plots, potentially suppressing pathogens and enhancing nutrient absorption. The study found that HMb increased microbial diversity in the rhizosphere, particularly Acidobacteria and Proteobacteria, which inhibited fungal growth. However, HMb had no significant impact on P. noxius populations. Overall, HMb treatment shows promise in enhancing plant health by improving microbial diversity and soil conditions, but further research is needed to understand its full impact on pathogen suppression and soil health restoration.

Combination of irradiated chitosan and microbial agent to reduce downy mildew on grapevine cv. Thompson seedless.

Globally sustainable disease management ensuring high quality in grapes is in demand as it holds significant importance as a versatile fruit for consumption, winemaking, and production of various products such as grape juice, raisin, and grape-seed oil. The present paper reports a combination of nano-biotechnology as a promising strategy for enhancing plant health and fruit productivity in grapes combining Irradiated chitosan nanoparticles and bio-control agents. The Irradiated Chitosan with Bacillus subtilis and Trichoderma viridae and pesticides were evaluated for disease management. Percent disease index, percent disease control, and percent yield enhancement in Cymoxanil 8% + Mamcozeb 64% WP @ 0.2% treatment were as 17. 24%, 67.97% and 33.91% in 150 ppm Irradiated chitosan+B. subtilis were 19.83, 63.16, 30.41 and in Trichoderma 150 ppm Irradiated chitosan were 24.58, 54.33, and 27.40, respectively as compared to untreated crop with disease severity 53.84% PDI. Thus, irradiated chitosan and Bacillus subtilis elucidated a synergistic combination for residue-free efficient phytosanitary measures, which harnessed the strength of chitosan and bio-control agents for sustainable grape productivity. These findings will also pave the way for a deeper understanding of the synergistic interaction between Irradiated nanochitosan and bio-control agents for an eco-friendly and economically viable disease management strategy. The minimum temperature and morning relative humidity (RH I) had positive significance, with correlation coefficients of 0.484 and 0.485, respectively. The evening relative humidity (RH II) had a positive highly significant positive correlation coefficient of 0.664. Chitosan merits as a multiple stress tolerance enhancing agent that will further help in mitigating climate change adaptations in grapevines reducing reliance on chemical agro-inputs.

Association of soil bacterial diversity and composition with Fusarium wilt disease of bananas in Yogyakarta Province, Indonesia

Abstract. Kurniasari I, Wibowo A, Subandiyah S, Pattison AB. 2024. Association of soil bacterial diversity and composition with Fusarium wilt disease of bananas in Yogyakarta Province, Indonesia. Biodiversitas 25: 2264-2275. Infection of banana plants with Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc-TR4) leads to a cascade of changes in the rhizosphere, resulting in changes to the soil physicochemical properties and bacterial community composition. This study aimed to determine the core taxa associated with different soil physicochemical properties and disease statuses and to identify the factors exerting the greatest influence on the soil bacterial community composition of bananas in Special Region of Yogyakarta Province, Indonesia. Rhizospheric soil from healthy and infected plants was collected from four banana locations, including Kulon Progo, Gunungkidul, Bantul, and Sleman districts, at 10-30 cm depth between May and September 2021. Laboratory analysis was conducted for soil physicochemical properties, and the abundance of Foc-TR4 was undertaken. Additionally, 16S rRNA gene-based metagenomics analysis was used to quantify bacterial diversity in all samples. Soil type significantly influenced the abundance and composition of the bacterial community more than disease status did. Contrarily, disease status groups influenced the complexity of bacterial network interaction more than soil type. Actinobacteriota, Proteobacteria, Chloroflexi, Acidobacteriota, and Bacteriodota are the major phyla associated with all soils. This study identified 60 bacterial genera as core members of the banana rhizosphere. These core bacterial genera include various plant growth-promoting bacteria involved in nitrogen fixation, phytohormone production, siderophore production, and biocontrol mechanisms for producing antifungal compounds. Our work provides a basis for future research on the soil bacterial composition associated with banana plants to enhance plant health against Fusarium wilt disease.

Synthetic community derived from grafted watermelon rhizosphere provides protection for ungrafted watermelon against Fusarium oxysporum via microbial synergistic effects

BackgroundPlant microbiota contributes to plant growth and health, including enhancing plant resistance to various diseases. Despite remarkable progress in understanding diseases resistance in plants, the precise role of rhizosphere microbiota in enhancing watermelon resistance against soil-borne diseases remains unclear. Here, we constructed a synthetic community (SynCom) of 16 core bacterial strains obtained from the rhizosphere of grafted watermelon plants. We further simplified SynCom and investigated the role of bacteria with synergistic interactions in promoting plant growth through a simple synthetic community.ResultsOur results demonstrated that the SynCom significantly enhanced the growth and disease resistance of ungrafted watermelon grown in non-sterile soil. Furthermore, analysis of the amplicon and metagenome data revealed the pivotal role of Pseudomonas in enhancing plant health, as evidenced by a significant increase in the relative abundance and biofilm-forming pathways of Pseudomonas post-SynCom inoculation. Based on in vitro co-culture experiments and bacterial metabolomic analysis, we selected Pseudomonas along with seven other members of the SynCom that exhibited synergistic effects with Pseudomonas. It enabled us to further refine the initially constructed SynCom into a simplified SynCom comprising the eight selected bacterial species. Notably, the plant-promoting effects of simplified SynCom were similar to those of the initial SynCom. Furthermore, the simplified SynCom protected plants through synergistic effects of bacteria.ConclusionsOur findings suggest that the SynCom proliferate in the rhizosphere and mitigate soil-borne diseases through microbial synergistic interactions, highlighting the potential of synergistic effects between microorganisms in enhancing plant health. This study provides a novel insight into using the functional SynCom as a promising solution for sustainable agriculture.6UoEKpA3MAKccxe2Gy9v1zVideo

The Potential of Burkholderia sp. from Zea mays Roots as Plant Growth Promoting Rhizobacteria

Plant Growth-Promoting Rhizobacteria (PGPR) plays a crucial role in enhancing plant health, while Burkholderia sp. has been identified and has potential as a promising PGPR for maize plants. Recognizing the essential role of PGPR in plant health, this study explores how L-TRP addition might improve PGPR performance for better plant growth. Employing a completely randomized design, the study assesses the effects of Burkholderia sp. as PGPR on maize growth across three treatment groups: PGPR with L-TRP, PGPR without L-TRP, and a control group. The evaluation focuses on plant growth metrics, plant hormone production (auxin and gibberellin), and siderophore activity to gauge plant iron availability. Statistical analysis highlights that L-TRP supplementation notably increases auxin production in the PGPR + L-TRP group, surpassing the PGPR without L-TRP and control groups. Although both PGPR treatments elevate gibberellin levels compared to the control, auxin increase is the most significant outcome, indicating no substantial difference in gibberellin levels between the two PGPR groups. Enhanced siderophore production suggests improved iron assimilation for plants. The findings demonstrate that L-TRP supplementation with PGPR, particularly Burkholderia sp., effectively boosts maize growth, primarily through increased auxin and siderophore production. This combination presents a promising strategy for augmenting agricultural yields, especially for maize productivity, by leveraging the synergistic effects of soil microbes and nutrient supplementation.

Improving organic grape production: the effects of soil management and organic fertilizers on biogenic amine levels in Vitis vinifera cv., 'Royal' grapes

BackgroundThe integration of organic viticulture practices in grape cultivation represents a pivotal advancement towards sustainable agriculture, emphasizing the importance of environmentally friendly methods that enhance soil health, grape quality, and overall ecosystem biodiversity, thereby contributing significantly to the resilience and long-term sustainability of viticultural ecosystems. This study explored the effects of soil management practices, including chisel, disc harrow, and no tillage, as well as the impact of utilizing Antep radish, broccoli, and olive blackwater as fertilizer applications, on the biochemical composition, specifically biogenic amines (BAs), in the clusters of the 'Royal' grape cultivar within a vineyard setting.ResultsThroughout the three-year study, no tillage soil management consistently emerged as the most influential soil treatment for enhancing BAs in 'Royal' grape berries, especially in combination with Antep radish and olive blackwater fertilizer applications. Among fertilizer applications, the nontreated control vines consistently had the highest concentrations of critical BAs, such as putrescine, cadaverine, histamine, and dopamine, across different soil management practices. Among the soil management practices and fertilizer applications evaluated, the disc harrow soil management and olive blackwater fertilizer application generally yielded the lowest concentrations of BAs across several metrics.The PCA biplots indicated that experimental years have a similar effect on BA content in grape berries, with specific amines such as serotonin and dopamine being more affected in 2020, while cadaverine, histamine, spermidine, trimethylamine, and norepinephrine were more influenced in 2021, and putrescine, spermine, agmatine, and tryptamine in 2022.ConclusionThese findings hold significant implications for organic agriculture, emphasizing the nuanced influence of soil management practices and organic fertilizers on the BA composition of grape berries. Our results indicate the potential of tailored agricultural strategies to enhance plant health and quality, aligning with the principles of sustainability and environmental stewardship inherent to organic farming.Graphical

The Win-Win Effects of an Invasive Plant Biochar on a Soil-Crop System: Controlling a Bacterial Soilborne Disease and Stabilizing the Soil Microbial Community Network.

Biochar is increasingly being recognized as an effective soil amendment to enhance plant health and improve soil quality, but the complex relationships among biochar, plant resistance, and the soil microbial community are not clear. In this study, biochar derived from an invasive plant (Solidago canadensis L.) was used to investigate its impacts on bacterial wilt control, soil quality, and microbial regulation. The results reveal that the invasive plant biochar application significantly reduced the abundance of Ralstonia solanacearum in the soil (16.8-32.9%) and wilt disease index (14.0-49.2%) and promoted tomato growth. The biochar treatment increased the soil organic carbon, nutrient availability, soil chitinase, and sucrase activities under pathogen inoculation. The biochar did not influence the soil bacterial community diversity, but significantly increased the relative abundance of beneficial organisms, such as Bacillus and Sphingomonas. Biochar application increased the number of nodes, edges, and the average degree of soil microbial symbiotic network, thereby enhancing the stability and complexity of the bacterial community. These findings suggest that the invasive plant biochar produces win-win effects on plant-soil systems by suppressing soilborne wilt disease, enhancing the stability of the soil microbial community network, and promoting resource utilization, indicating its good potential in sustainable soil management.

Root rot destabilizes the Sanqi rhizosphere core fungal microbiome by reducing the negative connectivity of beneficial microbes.

The stability of microbial communities, especially among core taxa, is essential for supporting plant health. However, the impacts of disease infection on the stability of rhizosphere fungal core microbiome remain largely unexplored. In this study, we delved into the effects of root rot infestation on the community structure, function, network complexity, and stability of Sanqi fungal core microbiomes, employing amplicon sequencing combined with co-occurrence network and cohesion analyses. Our investigation revealed that root rot disease led to a decrease in the α-diversity but an increase in the β-diversity of the Sanqi fungal core microbiomes in the rhizosphere. Notably, Ilyonectria, Plectosphaerella, and Fusarium emerged as indicator species in the rhizosphere core microbiome of root rot-infected Sanqi plants, while Mortierella predominated as the dominant biomarker taxa in healthy soils. Additionally, root rot diminished the complexity and modularity of the rhizosphere networks by reducing the metrics associated with nodes, edges, degrees, and modularity. Furthermore, root rot resulted in a reduction in the proportion of negative connections in the network and the negative/positive cohesion of the entire core fungal microbiome. Particularly noteworthy was the observation that root rot infection destabilized the rhizosphere core fungal microbiome by weakening the negative connectivity associated with beneficial agents. Collectively, these results highlight the significance of the negative connectivity of beneficial agents in ensuring the stability of core microbial community.IMPORTANCERoot rot disease has been reported as the most devastating disease in the production process of artificial cultivated Sanqi ginseng, which seriously threatens the Sanqi industry. This study provides valuable insights into how root rot influences microbial relationships within the community. These findings open up opportunities for disease prevention and the promotion of plant health by regulating microbial interactions. In summary, the research sheds light on the ecological consequences of root rot on rhizosphere fungal microbiomes and offers potential strategies for managing soil-borne diseases and enhancing plant health.

Does chitosan affect bulb yield and quality of sweet onion (Allium cepa L.)?

ABSTRACT Chitosan, a polymer derived from shellfish, may enhance plant health and have antimicrobial properties. Effects of chitosan applications to sweet onion (Allium cepa L.) in the field on bulb yield and quality were evaluated. The study was conducted in Tifton (sandy loam) and Reidsville (loamy sand), GA, during the 2015–2016 and 2016–2017 winter seasons (Dec. to May). “Century” sweet onion seedlings were transplanted to beds (1.8-m centers) in mid-December. Treatments were chitosan (117 mg·L−1) applied before transplanting plus monthly applications at 0, 1, 2, 3, and 4 months after transplanting, and an untreated control (water). Harvested bulbs were stored for 3 mo [2.0°C, 80% RH, 0.586 kPa of vapor pressure deficit, 4% CO2, and 10% O2]. Chitosan did not affect bulb marketable and total number and weight, individual bulb weight, and incidence of bulb sour skin (caused by Burkholderia cepacia). Immediately after harvest, chitosan did not influence bulb dry matter, soluble solids concentration, pungency, and total phenols concentration. However, after 3 months of storage, bulb SSC and total phenols decreased, and bulb dry matter and pungency increased. In conclusion, chitosan applications before and during sweet onion production did not affect marketable or total bulb yield, bulb sour skin incidence, or bulb chemical composition.