Plant Growth Promotion Research Articles

Pecan-medicinal crops intercropping improved soil fertility and promoted interactions between soil microorganisms and metabolites

BackgroundPecan [Carya illinoinensis (Wangenh.) Koch] is a widely cultivated dried fruit and woody oil tree with high economic value. Continuous sole planting of pecan caused some land to lie idle and deterioration of soil conditions. Tree and medicinal crops intercropping represents an environmental-friendly and economically feasible solution to these issues. Thus, we aimed to explore the underlying mechanism by which intercropping improved soil condition by regulating the interactions of the soil microbiome and metabolome. In this study, pecans were intercropped with medicinal crops caper spurge and honeysuckle on a tree farm in China. A combined analysis of soil microbiomes and metabolomes was performed to discover the effects of intercropping on bulk and rhizosphere soils.ResultsThe results showed that intercropping improved the edaphic properties of bulk soil and promoted the growth of pecan and caper spurge. Intercropping also significantly altered the structures of both bacterial and fungal communities in bulk soil, stabilised the enrichment of nitrogen-cyclic bacteria, for instance, Bacillus, and decreased the relative abundances of plant–pathogenic fungi, for instance, Fusarium. In addition, the result of metabolomic analysis showed that intercropping promoted the synthesis of functional compounds, such as trehalose and ethanolamine, which enhanced plant disease resistance in bulk soils. Moreover, the co-occurrence networks of microbiomes and metabolomes of bulk soils revealed that Bacillus was significantly correlated with Fusarium, Alternaria, and trehalose under intercropping patterns. Furthermore, analysis of microbiomes and metabolomes in the rhizosphere soil of caper spurge and honeysuckle revealed that Penicillium and Rhizomicrobium were significantly increased by intercropping and showed more dynamic connections with other genera and metabolites compared with single planting.ConclusionsOverall, intercropping pecans with caper spurge and honeysuckle can improve soil conditions and promote plant growth through microbiological and metabolomics integrated analyses. This study provides valuable information and theoretical basis for optimizing land resource utilisation and improving soil conditions in tree fields like pecan fields via intercropping, thereby reducing production losses and ensuring economic benefits.Graphical

Melatonin Ameliorates Cadmium Toxicity in Tobacco Seedlings by Depriving Its Bioaccumulation, Enhancing Photosynthetic Activity and Antioxidant Gene Expression

Soil remediation for cadmium (Cd) toxicity is essential for successful tobacco cultivation and production. Melatonin application can relieve heavy metal stress and promote plant growth; however, it remains somewhat unclear whether melatonin supplementation can remediate the effects of Cd toxicity on the growth and development of tobacco seedlings. Herein, we evaluated the effect of soil-applied melatonin on Cd accumulation in tobacco seedlings, as well as the responses in growth, physiological and biochemical parameters, and the expression of stress-responsive genes. Our results demonstrate that melatonin application mitigated Cd stress in tobacco, and thus promoted plant growth. It increased root fresh weight, dry weight, shoot fresh weight and dry weight by 58.40%, 163.80%, 34.70% and 84.09%, respectively, compared to the control. Physiological analyses also showed significant differences in photosynthetic rate and pigment formation among the treatments, with the highest improvements recorded for melatonin application. In addition, melatonin application alleviated Cd-induced oxidative damage by reducing MDA content and enhancing the activities of enzymatic antioxidants (CAT, SOD, POD and APX) as well as non-enzymatic antioxidants (GSH and AsA). Moreover, confocal microscopic imaging confirmed the effectiveness of melatonin application in sustaining cell integrity under Cd stress. Scanning Electron Microscopy (SEM) observations illustrated the alleviative role of melatonin on stomata and ultrastructural features under Cd toxicity. The qRT-PCR analysis revealed that melatonin application upregulated the expression of photosynthetic and antioxidant-related genes, including SNtChl, q-NtCSD1, NtPsy2 and QntFSD1, in tobacco leaves. Together, our results suggest that soil-applied melatonin can promote tobacco tolerance to Cd stress by modulating morpho-physiological and biochemical changes, as well as the expression of relevant genes.

Screening Surface-Defective Graphene Quantum Dots: Promoting Plant Growth and Combating Phytovirus.

Reduced graphene quantum dots (r-GQD), graphene oxide quantum dots (GOQD), and carboxylated graphene quantum dots (C-GQD) are screened to promote tobacco growth and combat tobacco mosaic virus (TMV). First, a 21-day foliar exposure is employed to explore GQDs' impacts on N. benthamiana. Surface-defective GOQD and C-GQD are screened out to facilitate N. benthamiana uptake through leaf stomata, and to promote seedlings of differently leaf ages to various degrees at different concentrations after different durations of foliar exposure. Specially, compared to the ddH2O treatment, GOQD/C-GQD at 400 mg L-1 increase biomass by 44%/68%, increase chlorophyll content by 43%/54% and up-regulate the expression of growth-related genes NtLRX1, CycB, and NtPIP1 by more than two-fold. Second, different from the transient inhibition shown by r-GQD and the TMV enhancement shown by GOQD, C-GQD can directly inactivate TMV infection by inducing TMV aggregation and attachment outside TMV, significantly decreasing TMV replication and hindering TMV spread over 21-day. Specially, C-GQD decreases the transcript abundance of TMV RdRp and TMV CP to 0.11-fold and 0.29-fold, and down-regulates the host defensive response pathways. This work provides a comparative analysis of GQDs with different surface-functionalizations, highlighting C-GQD as a promising nanotechnology tool for promoting plant growth and inactivating phytovirus.

The Effect of Eco-Friendly Deicing Agents Containing Humic Acid on Plant Growth

Objectives:In this experiment, we used an environmentally friendly snow removal agent containing calcium chloride (CaCl2) and humic acid (HA) to alleviate salt stress on chili pepper seedlings, and analyzed its effect on plant growth. As an alternative to minimize the negative effects of existing chloride-based snow removal agents on plants and soil, we investigated whether humic acids contribute to improving plant physiological responses and soil electrical conductivity (EC). Evaluated.Methods:For 21 days, we set up a control group (Count.), a calcium chloride treatment group (CaCl2), a humic acid treatment group (HA), and a mixed treatment group (HUA2, HUA5, HUA10) in which humic acid and calcium chloride were mixed. The growth of stems and roots was measured. In addition, the high mortality rate of leaves and changes in soil electrical conductivity (EC) were measured to evaluate the effect of alleviating salt stress.Results and Discussion:As a result of the experiment, stem length increased in the control group, humic acid treatment group (HA), and humic acid and calcium chloride mixed treatment groups (HUA2, HUA5, HUA10), and the greatest growth was observed in HUA5 among the mixed treatment groups. On the other hand, in the calcium chloride treatment group (CaCl2), stem growth did not occur and the high leaf mortality rate was 66.7%, which had a negative effect on growth. The soil EC value was lowest at 0.21mS/cm in the humic acid only treatment group (HA) and highest at 1.25mS/cm in the calcium chloride treatment group (CaCl2). In the mixed treatment group, the EC value tended to decrease as the humic acid concentration increased. This indicates that humic acid can play a role in reducing salt stress and promoting plant growth.

Exploring Trichoderma Diversity for Sustainable Disease Management in Lolium perenne Against Fusarium avenaceum

AbstractFusarium species represent a significant threat to pasture health, necessitating the development of sustainable solutions. This study explores the potential of regionally adapted Trichoderma isolates for controlling Fusarium avenaceum and promoting plant growth in the grasslands of the Iberian Peninsula. To this end, seven Trichoderma isolates (belonging to T. koningiopsis, T. koningii and T. gamsii) were obtained from soils of Extremadura and then evaluated as potential biocontrol agents against Fusarium avenaceum. For the purposes of this evaluation, water was used as a negative control, while a commercial Trichoderma product served as a positive control. An initial in vitro evaluation revealed that six Trichoderma isolates significantly inhibited F. avenaceum in a dual culture assay, reducing pathogen growth by 18 to 49%. Additionally, two of the isolates showed antifungal potential during the evaluation of their culture filtrates. Subsequently, two greenhouse assays were conducted to assess the effects of Trichoderma isolates and the pathogen on the development of Lolium perenne. One focused on seed germination and the other on established plants. The greenhouse experiments indicated that T08 (T. koningiopsis), T14 (T. koningii), and T19 (T. gamsii) significantly improved seed germination and plant growth, even outperforming the positive control on total dry matter in pathogen-infected plants during the postemergence test. Our study highlights the potential of Trichoderma isolates, particularly T08, T14, and T19, to boost plant growth and control Fusarium avenaceum in Lolium perenne. It emphasizes the importance of in planta testing and reveals the varying effects of the isolates throughout the plant cycle.

Preparation of Loess‐Clay Based Eco‐Friendly Geopolymer for Efficient Removal of Pollutants in Water

AbstractHeavy metals and dyes cause serious harm for water environment, geopolymer materials with the large pores and specific surface area, and easy modification of pore surface have received extensive attention in wastewater treatment. Herein, using loess‐clay (LC) as natural mineral materials, we developed an eco‐friendly geopolymer of loess‐clay (GpLC) with excellent adsorption properties and promotion plant growth was prepared by alkali excitement. Its morphology and structure were exhibited by scanning electron microscopy, Fourier transform infrared spectroscopy, XRD, and Brunauer–Emmett–Teller. Moreover, its adsorption property for removing metal ions and different dyes was measured, and the adsorption kinetics and thermodynamics were investigated. GpLC presented excellent adsorption ability for Pb2+, which the removal rate got to 98.7 %. It had the universality of removing organic pollutants, and the removal rate reached to 98.0 %. It was dominated chemisorption and single‐layer adsorption, which GpLC conformed to quasi‐second‐order adsorption kinetics, and being more consistent with Langmuir isothermal model. Furthermore, it was found that GpLC could promote growth of crops as it contain P and K element with essential element of plants. In summary, it provides insights and strategy for developing a kind of eco‐friendly functional materials with strong adsorption capacity and promoting plant growth, and it is an effective method for reusing loess resources.

Fibrillin gene family and its role in plant growth, development, and abiotic stress

Fibrillins (FBNs), highly conserved plastid lipid-associated proteins (PAPs), play a crucial role in plant physiology. These proteins, encoded by nuclear genes, are prevalent in the plastoglobules (PGs) of chloroplasts. FBNs are indispensable for maintaining plastid stability, promoting plant growth and development, and enhancing stress responses. The conserved PAP domain of FBNs was found across a wide range of photosynthetic organisms, from plants and cyanobacteria. FBN families are classified into 12 distinct groups/clades, with the 12th group uniquely present in algal–fungal symbiosis. This mini review delves into the structural attributes, phylogenetic classification, genomic features, protein–protein interactions, and functional roles of FBNs in plants, with a special focus on their effectiveness in mitigating abiotic stresses, particularly drought stress.

The Impact of Beneficial Microorganisms on Soil Vitality: A Review

The paper summarizes the literature on the critical impact of beneficial microorganisms on soil vitality. Common soil microorganisms, including bacteria, fungi, algae, protozoa, and viruses contribute significantly to enhancing soil fertility through processes such as nitrogen fixation, phosphorus solubilization and mobilization, sulfur cycle, composting, and heavy metal remediation. Their abundance and biomass vary significantly across taxa within the uppermost 15 cm of soil, with bacteria dominating numerically and fungi contributing substantially to biomass. These microorganisms mediate essential biogeochemical cycles in soil, including carbon, nitrogen, and phosphorus cycles, by facilitating the decomposition of organic matter and recycling soil nutrients. Nitrogen-fixing bacteria like Rhizobium are prevalent symbionts capable of biologically fixing nitrogen. Additionally, bacteria such as Micrococcus spp., Enterobacter aerogens, Pseudomonas capacia, fungi including Aspergillus niger, A. flavus, A. japonicas, Penicillum spp., and actinomycetes like Streptomyces play crucial roles in phosphorus solubilization, making phosphorus available for plant uptake. This synthesis underscores the critical role of beneficial microorganisms in maintaining soil vitality. These organisms interact with plants through beneficial relationships, influencing soil fertility dynamics by enhancing nutrient availability, promoting plant growth, and controlling pathogens. The use of biofertilizers has emerged as a sustainable strategy to improve crop yields and restore soil fertility, reducing environmental impacts linked to chemical fertilizers. Understanding the intricate dynamics of soil-beneficial microorganism and their interactions with Plants are pivotal for optimizing agricultural practices, ensuring long-term soil health, and enhancing productivity in sustainable farming systems.

Efficacy of two different microbial consortia on salinity tolerance in chickpea: an in-planta evaluation on biochemical, histochemical, and genomic aspects.

This study aimed to identify and characterize actinobacteria and rhizobia with plant growth-promoting (PGP) traits from chickpea plants. Out of 275 isolated bacteria, 25 actinobacteria and 5 chickpea rhizobia showed 1-aminocyclopropane-1-carboxylate deaminase (ACCd) activity. Selected chickpea rhizobia were tested for their nodulating capacity under sterile and non-sterile soil conditions. Further screening on salinity and PGP traits identified three promising isolates: Nocardiopsis alba KG13, Sinorhizobium meliloti KGCR17, and Bacillus safensis KGCR11. These three isolates were analyzed for their compatibility and made into a consortium (Consortium 1). This along with another consortium made from our salinity-tolerant lab strains Chryseobacterium indologenes ICKM4 and Stenotrophomonas maltophilia ICKM15 (Consortium 2) was compared in planta studies. Trials revealed that Consortium 2 showed significant (p < 0.05) tolerance and on above-ground, below-ground traits and yield components than Consortium 1. Moreover, both consortia induced nodulation in saline-stressed plants, alleviated electrolyte leakage (2.3 vs. 0.4 in ICCV 2; 1.8 vs. 0.6 in JG 11), and increased chlorophyll content. Histochemical staining indicated reduced oxidative stress and lipid peroxidation in consortium-treated plants under salinity stress. Further, gene expression studies revealed mixed patterns, with up-regulation of antioxidant and transporter genes observed in consortium-treated plants, particularly in Consortium 2. Overall, Consortium 2 showed better gene expression levels for antioxidant and transporter genes, indicating its superior efficacy in mitigating salinity stress in chickpea plants. This study provides valuable insights into the potential use of these microbial isolates in improving chickpea productivity by enhancing salinity tolerance.

Isolation of Heavy Metal-Tolerant and Anti-Phytopathogenic Plant Growth-Promoting Bacteria from Soils.

In this study, by isolating multifunctional soil bacteria that can promote plant development, resist heavy metals, exhibit anti-phytopathogenic action against plant diseases, and produce extracellular enzymes, we hope to improve the effectiveness of phytoremediation techniques. To isolate multifunctional soil bacteria, we used soils with diverse characteristics as isolation sources. To look into the diversity and structural traits of the bacterial communities, We conducted amplicon sequencing of the 16S rRNA gene on five types of soils and predicted functional genes using Tax4Fun2. The isolated bacteria were evaluated for their multifunctional capabilities, including heavy metal tolerance, plant growth promotion, anti-phytopathogenic activity, and extracellular enzyme activity. The genes related to plant growth promotion and anti-phytopathogenic activity were most abundant in forest and paddy soils. Burkholderia sp. FZ3 and FZ5 demonstrated excellent heavy metal resistance (≤ 1 mM Cd and ≤ 10 mM Zn), Pantoea sp. FC24 exhibited the highest protease activity (24.90 μmol tyrosine·g-DCW-1·h-1), and Enterobacter sp. PC20 showed superior plant growth promotion, especially in siderophore production. The multifunctional bacteria isolated using traditional methods included three strains (FC24, FZ3, and FZ5) from the forest and one strain (PC20) from paddy field soil. These results indicate that, for the isolation of beneficial soil microorganisms, utilizing target gene information obtained from isolation sources and subsequently exploring target microorganisms is a valuable strategy.

Varying levels of natural light intensity affect the phyto-biochemical compounds, antioxidant indices and genes involved in the monoterpene biosynthetic pathway of Origanum majorana L.

BackgroundLight is a critical environmental factor in plants, encompassing two vital aspects: intensity and quality. To assess the influence of different light intensities on Origanum majorana L., pots containing the herb were subjected to four levels of light intensity: 20, 50, 70, and 100% natural light. After a 60-day treatment period, the plants were evaluated for metabolite production, including total sugar content, protein, dry weight, antioxidant indices, expression of monoterpenes biosynthesis genes, and essential oil compounds. The experimental design followed a randomized complete blocks format, and statistical analysis of variance was conducted.ResultsThe results indicated a correlation between increased light intensity and elevated total sugar and protein content, which contributed to improved plant dry weight. The highest levels of hydrogen peroxide and malondialdehyde (MDA) were observed under 100% light intensity. Catalase and superoxide dismutase enzymes exhibited increased activity, with a 4.23-fold and 2.14-fold increase, respectively, under full light. In contrast, peroxidase and polyphenol oxidase enzyme activities decreased by 3.29-fold and 3.24-fold, respectively. As light intensity increases, the expression level of the 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) gene increases. However, beyond a light intensity of 70%, the DXR gene expression level decreased. Furthermore, the expression levels of the cytochrome P450 genes CYP71D178 and CYP71D179 exhibited an increasing trend in response to elevated light intensity. Essential oil content increased from 0.02 to 0.5% until reaching 70% light intensity. However, with further increases in light intensity, the essential oil content decreased by 54 to 0.23%.ConclusionsThese findings emphasize the importance of balancing plant growth promotion and stress management under different light conditions. The research suggests that sweet marjoram plants thrive best in unshaded open spaces, resulting in maximum biomass. However, essential oil production decreases under the same conditions. For farmers in areas with an average light intensity of approximately 1700 µmol m−2s−1, it is recommended to cultivate sweet marjoram in shade-free fields to optimize biomass and essential oil production. Towards the end of the growth cycle, it is advisable to use shades that allow 70% of light to pass through. The specific duration of shade implementation can be further explored in future research.

Effects of Microbial Organic Fertilizer, Microbial Inoculant, and Quicklime on Soil Microbial Community Composition in Pepper (Capsicum annuum L.) Continuous Cropping System

The additions of microbial organic fertilizer (MOF), a microbial inoculant (MI), and quicklime (Q) are considered to be sustainable practices to restore land that has been damaged by continuous cropping of pepper (Capsicum annuum L.). However, the combined effects of these three additives on pepper yield, soil chemical properties, and soil microbial communities were unclear. The experimental design consists of 13 treatment groups: the untreated soil (control); soil amended solely with three treatments for each of MOF (1875–5625 kg ha−1), MI (150–450 mL plant−1), and Q (1500–4500 kg ha−1); and soil amended with combinations of MOF, MI, and Q at three comparable concentrations. A significant increase in pepper fruit diameter, length, yield, and soil available nitrogen, phosphorus, and potassium contents occurs upon exclusive and combined applications of MOF, MI, and Q. Pepper yield was greatest (29.89% more than control values) in the combined treatment with concentrations of 1875 kg ha−1 MOF, 150 mL plant−1 MI, and 1500 kg ha−1 Q. The application of Q increased soil pH and reduced soil–fungal richness. The application of MOF, MI, and Q increased the relative abundance of bacterial genera and the complexity of bacterial and fungal co-occurrence networks compared with control levels. The combined application of MOF, MI, and Q resulted in the greatest microbial network complexity. A Mantel test revealed the key role of soil available nitrogen content and bacterial diversity in the regulation of pepper growth and yield. We conclude that the combined application of MOF, MI, and Q improves soil nutrient availability and modifies soil microbial community composition, significantly promoting plant growth and pepper yield during continuous cultivation.

Isolation and Identification of Multi-Traits PGPR for Sustainable Crop Productivity Under Salinity Stress

High salinity poses a significant threat to arable land globally and contributes to desertification. Growth-promoting rhizobacteria assist plants in mitigating abiotic stresses and enhancing crop productivity through the production of siderophores, exopolysaccharides (EPS), solubilisation of phosphate, indole-3-acetic acid (IAA), and other secondary metabolites. This study aimed to isolate, identify, and characterise bacteria that exhibit robust growth-promoting properties. A total of 64 bacterial isolates from the rhizosphere of Miscanthus sinensis were evaluated for plant growth-promoting (PGP) traits, including IAA, EPS, siderophores, and solubilisation of phosphate. Among them, five isolates were selected as plant growth-promoting rhizobacteria (PGPR) based on their PGP features and identified via 16S rRNA sequencing: Enterococcus mundtii strain INJ1 (OR122486), Lysinibacillus fusiformis strain INJ2 (OR122488), Lysinibacillus sphaericus strain MIIA20 (OR122490), Pseudomonas qingdaonensis strain BD1 (OR122487), and Pseudomonas qingdaonensis strain MIA20 (OR122489), all documented in NCBI GenBank. BD1 demonstrated a higher production of superoxide dismutase (SOD) (17.93 U/mg mL), catalase (CAT) (91.17 U/mg mL), and glutathione (GSH) (0.18 U/mg mL), along with higher concentrations of IAA (31.69 µg/mL) and salicylic acid (SA) (14.08 ng/mL). These isolates also produced significant quantities of amino and organic acids. BD1 exhibited superior PGP traits compared to other isolates. Furthermore, the NaCl tolerance of these bacterial isolates was assessed by measuring their growth at concentrations ranging from 0 to 200 mM at 8-h intervals. Optical density (OD) measurements indicated that BD1 and INJ2 displayed significant tolerance to salt stress. The utilisation of these isolates, which enhances plant growth and PGP traits under salt stress, may improve plant development under saline conditions.

Isolation, Identification, and Application of Endophytic Fungi from Lavandula stoechas L.: Mitigating Salinity Stress in Hydroponic Winter Cereal Fodder

Soil and irrigation water salinity is a growing global problem affecting farmland, due to poor agricultural practices and climate change, leading to reduced crop yields. Given the limited amount of arable land and the need to boost production, hydroponic systems offer a viable solution. Additionally, endophytic fungi have been shown to mitigate salinity effects through symbiosis with plants. This study evaluated three endophytic fungi isolated from Lavandula stoechas L. in the grasslands of Extremadura (i.e., Diplodia corticola L11, Leptobacillium leptobactrum L15, and Cladosporium cladosporioides L16) for their ability to improve hydroponic forage production under saline conditions. In vitro experiments were conducted assessing plant growth promotion and fungal growth under salinity, followed by research evaluating the impact of fungal inoculation on hydroponic wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) forages irrigated with NaCl solutions (0, 100, and 200 mM). The results showed improved fungal growth and production of plant growth-promoting substances, which could explain the improved plant germination, shoot and root length, fresh and dry weight, and yield of inoculated plants growing under salinity. Plants inoculated with L15 or L16 showed the best performance overall. L15 demonstrated broader bioactivity in vitro, potentially explaining its superior performance in both wheat and barley growth. Conversely, L16 was more effective in barley, while L11 was beneficial in wheat but detrimental in barley. This study provides a preliminary exploration of the capabilities of these fungi and their optimization for hydroponic forage production.

Long-Life Inoculant: Bradyrhizobium Stored in Biodegradable Beads for Four Years Shows Optimal Cell Vitality, Interacts with Peanut Roots, and Promotes Early Growth

Currently, bacterial inoculant technology focuses on improving long-term storage conditions to ensure adequate rhizobia numbers and their effectiveness as plant growth promoters. This study aimed to investigate whether storage at 4 °C for four years of alginate beads immobilizing Bradyrhizobium sp. SEMIA6144 maintains bacterial vitality, efficacy in growth promotion, and ability to establish early interactions with Arachis hypogaea L. The recovery of viable SEMIA6144 cells decreased over time (10% at six months, 1% at one year, and 0.01% at four years), while cell vitality remained high at 94.1%, 90.2%, and 93.4%, respectively. The unsaturated/saturated fatty acid ratio declined during storage, reducing membrane fluidity and metabolic activity. Mobility and root adhesion of SEMIA6144 decreased after one and four years. However, growth promotion in peanuts inoculated with SEMIA6144 beads was observed through increased biomass, total chlorophyll, leaf number, leaf area, and decreased chlorophyll fluorescence compared to non-inoculated plants. Although nodulation was low in plants inoculated with four-year-old beads, leghemoglobin levels were maintained. These results demonstrate that Bradyrhizobium sp. SEMIA6144 can be stored for four years in alginate beads at 4 °C, maintaining its vitality and ability to establish a symbiosis that stimulates early peanut growth. Understanding these physiological changes could be valuable for the future improvement of long-lasting inoculants.

Functions and mechanisms of CDPKs in plant responses to abiotic stress

Calcium-dependent protein kinases (CDPKs/CPKs) are members of the Ca2+-sensitive Ser/Thr protein kinase family and play a crucial role in plant growth and development and responses to abiotic stress. CDPKs are capable of rapidly sensing changes in intracellular Ca2+ signals and recognizing and phosphorylating specific substrates, thereby transmitting and amplifying Ca2+ signal cascades downstream. They are involved in plant responses to stress conditions such as drought, saline-alkali stress, and injuries and regulate plant growth and development, gene expression, ion channel activity, and stomatal movement. The autophosphorylation of CDPKs can affect their activities and substrate specificity. CDPKs have the ability to bind to and phosphorylate multiple substrates. In addition to participating in respiratory burst oxidase homolog (RBOH), mitogen-activated protein kinase (MAPK), and plant hormone signaling pathways, CDPKs can also bind to 14-3-3 proteins, which enables the regulation of plant responses to stress and promotes plant growth and development. This paper summarized the research findings on the discovery, structure, classification, and roles of CDPKs in plant responses to stress and proposed the future research directions, aiming to provide the genetic resources and a theoretical basis for improving the stress tolerance of crops.

Versatile MXenzymes Scavenging ROS for Promotion of Seed Germination under Salt Stress.

Salinization is recognized as a global problem, restricting agricultural production and sustainability. Targeting the salinity-induced oxidative stress, antioxidant treatment represents a protective strategy to improve plant salt tolerance. Herein, we report a V4C3 MXene nanozyme (MXenzyme), which exhibits good biocompatibility and excellent reactive oxygen species scavenging activity to ameliorate the salt stress-induced inhibition of seed germination. V4C3 MXenzyme treatment can significantly relieve salinity-induced oxidative stress and restore the antioxidant system in pea seeds, thus improving the phenotypic traits during germination. The molecular mechanism by which antioxidant V4C3 MXenzymes augment salt tolerances is revealed through transcriptomics and metabolomics. V4C3 MXenzymes significantly regulate the gene expression of antioxidant enzymes and molecule biosynthesis that correlate closely with hormone signal transduction genes and energy metabolism genes. With correlation and the combined analysis, redox homeostasis targeted by antioxidant V4C3 MXenzymes plays a critical role in promoting plant growth under salt stress.

Evaluation of Lactiplantibacillus argentoratensis MYSJK8 from Jackfruit for Its Multifarious Antibacterial, Probiotic, Plant Growth Promoting and Bio-control Attributes

Evaluation of Lactiplantibacillus argentoratensis MYSJK8 from Jackfruit for Its Multifarious Antibacterial, Probiotic, Plant Growth Promoting and Bio-control Attributes

Impacts of Light Exposure and Soil Covering on Sweet Potato Storage Roots in a Novel Soilless Culture System

Soilless culture systems, which promote plant growth and enable the precise control of the root-zone environment, have yet to be fully established for sweet potatoes. In this study, we developed a soilless culture system and examined the effects of soil covering and light exposure on the storage roots of sweet potatoes. Sweet potato seedlings with induced storage roots were transplanted into five systems: a previously developed pot-based hydroponics system (Pot), an improved version with storage roots enclosed in a plastic box and covered with a soil sheet (SS), the SS system without the soil sheet (SD), the SD system with light exposure to storage roots after 54 days (SL), and a deep flow technique (DFT) hydroponics system. Our study enabled the time-course observation of storage root enlargement in the SS, SD, and SL systems. In the SL system, light exposure suppressed the storage root enlargement and reduced epidermal redness. No storage root enlargement was observed in the DFT system, even at 151 days after transplantation. Light exposure in the SL system increased the chlorophyll and total phenolic contents in the cortex beneath the epidermis, while the starch content was the lowest in this system. These findings indicate that the developed system can induce normal storage root enlargement without soil. Additionally, the observed changes in growth and composition due to light exposure suggest that this system is effective for controlling the root-zone environment of sweet potatoes.

Molecular interactions of Trichoderma: from microbial competition to soil health promotion

The increasing demand for sustainable solutions to agricultural pest and disease management has positioned Trichoderma fungi as a promising biological control agent. Trichoderma is not only capable of suppressing various plant pathogens but also promotes plant growth and strengthens natural plant defenses. This mini-review explores the molecular mechanisms underlying Trichoderma's ability to function as a biocontrol agent, focusing on nutrient competition, antibiotic production, mycoparasitism, and the induction of plant resistance. Additionally, advances in genomics and transcriptomics have facilitated a deeper understanding of the signaling pathways and genes responsible for Trichoderma's biocontrol effectiveness, including G-protein and MAPK pathways. Beyond pathogen suppression, Trichoderma plays a key role in enhancing soil health and establishing symbiotic relationships with plants, contributing to improved nutrient absorption and growth hormone production. However, challenges remain in translating laboratory success to large-scale field applications. This mini review highlights the need for further research on optimizing Trichoderma formulations, understanding its interaction with other beneficial soil organisms, and exploring genetic engineering to enhance its biocontrol capabilities. The future of Trichoderma lies in its integration into holistic, agroecological systems alongside other sustainable pest management strategies.