Plant Growth Promotion Research Articles

Enhanced Stability and Brightness through Co-Substitution: Promoting Plant Growth with Green-Excited Deep Red Phosphor Ca1-zSrzLi1-xMg2xAl3-xN4:yEu2.

The research utilized a strategy of chemical unit co-substitution, successfully developing a novel blue-green to green excited, deep red-emitting phosphor, Ca1-zSrzLi1-xMg2xAl3-xN4:yEu2+ (CLA-2xM-zS:yEu, 0≤x≤0.8, 0.003≤y≤0.01, 0≤z≤1), through the replacement of [Li-Al]4+ by [Mg-Mg]4+. This phosphor uniquely converts unusable green light to growth-enhancing deep red, optimizing it for outdoor agriculture. Doping with Sr creates traps, causing a redshift in emission peaks, as confirmed by 7Li nuclear magnetic resonance (NMR) spectra, indicating Li presence and lattice changes. Ca0.2Sr0.8Li0.5MgAl2.5N4:0.005Eu2+ (CLAM-0.8S) phosphor maintained high luminescence intensity under extreme conditions of 85°C/85% RH, demonstrating excellent photoluminescence performance and chemical stability, compared with conventional SrLi0.5MgAl2.5N4:0.005Eu2+ (SLMA) and SrLiAl3N4:0.005Eu2+(SLA). Experimental results surprised that the unique Ca0.2Sr0.8Li0.8Mg0.4Al2.8N4:0.005Eu2+ (CLA-0.4M-0.8S) prepared light-converting film, which is mainly excited by green light, demonstrated a 20% increase in optical density of Chlorella compared to the PP film and a remarkable 97.5% increase compared to the control group without any film. These findings suggest that this film has significant potential for applications in outdoor agriculture and other fields.

Unveiling the Role of Edaphic Microalgae in Soil Carbon Sequestration: Potential for Agricultural Inoculants in Climate Change Mitigation

Agricultural soil has great potential to address climate change issues, particularly the rise in atmospheric CO2 levels. It offers effective remedies, such as increasing soil carbon content while lowering atmospheric carbon levels. The growing interest in inoculating soil with live microorganisms aims to enhance agricultural land carbon storage and sequestration capacity, modify degraded soil ecosystems, and sustain yields with fewer synthetic inputs. Agriculture has the potential to use soil microalgae as inoculants. However, the significance of these microorganisms in soil carbon sequestration and soil carbon stabilization under field conditions has yet to be fully understood. Large-scale commercial agriculture has focused on the development and use of inoculation products that promote plant growth, with a particular emphasis on enhancing yield attributes. Gaining more profound insights into soil microalgae’s role in soil carbon cycling is necessary to develop products that effectively support soil carbon sequestration and retention. This review comprehensively explores the direct and indirect mechanisms through which soil microalgae contribute to soil carbon sequestration, highlighting their potential as microbial inoculants in agricultural settings. This study underlines the need for more research to be conducted on microalgae inoculation into agricultural soil systems aimed at mitigating carbon emissions in the near future.

Addressing cadmium stress in rice with potassium-enriched biochar and Bacillus altitudinis rhizobacteria.

Cadmium (Cd) is a potentially harmful metal with significant biological toxicity that adversely affects plant growth and physiological metabolism. Excessive Cd exposure in plants leads to stunted plant growth owing to its negative impact on physiological functions such as photosynthesis, nutrient uptake, and water balance. Potassium-enriched biochar (KBC) and Bacillus altitudinis rhizobacteria (RB) can effectively overcome this problem. Potassium-enriched biochar (KBC) significantly enhances plant growth by improving the soil structure, encouraging water retention, and enhancing microbial activity as a slow-release nutrient. Rhizobacteria promote plant growth by improving root ion transport and nutrient availability while promoting soil health and water conservation through RB production. This study examined the effects of combining RB + KBC as an amendment to rice, both with and without Cd stress. Four treatments (control, KBC, RB, and RB + KBC) were applied using a completely randomized design (CRD) in four replications. The results showed that the combination of RB + KBC increased rice plant height (38.40%), shoot length (53.90%), and root length (12.49%) above the control under Cd stress. Additionally, there were notable improvements in chlorophyll a (15.31%), chlorophyll b (25.01%), and total chlorophyll (19.37%) compared to the control under Cd stress, which also showed the potential of RB + KBC treatment. Moreover, increased N, P, and K concentrations in the roots and shoots confirmed that RB + KBC could improve rice plant growth under Cd stress. Consequently, these findings suggest that RB + KBC is an effective amendment to alleviate Cd stress in rice. Farmers should use RB + KBC to achieve better rice growth under cadmium stress.

A Two-Way Street: How Are Yeasts Impacted by Pesticides and How Can They Help Solve Agrochemical Contamination Problems?

Plant-associated yeasts play significant ecological roles within the microbiomes of soils and pollinating insects. In previous studies, we have shown that yeasts can assist pollinators in locating nectar, which is crucial for their nutrition and the reproduction of many angiosperms. Additionally, in soil, yeasts can also act as plant growth promoters. Given the importance of yeasts for plant development, this review first explores the biochemical processes underlying the ecological role of these microorganisms in soil, insects, and in direct association with plants. Based on this premise, we discuss the influence of these relationships on agricultural production, the biological mechanisms through which pesticides negatively affect yeast cells, and how these microorganisms can tolerate widely used agrochemicals. Finally, we address key studies in the literature that support the potential of these microorganisms as bioremediation agents. In this context, we emphasize different experiences with both indigenous and genetically engineered yeasts, which may display enzymes in their surfaces that convert pesticides into less harmful or nontoxic molecules. Our review indicates that yeasts can be effectively harnessed in organic agriculture to promote plant growth and bioremediate contaminated soil or food.

Emerging Nanochitosan for Sustainable Agriculture

Chemical-intensive agriculture challenges environmental sustainability and biodiversity and must be changed. Minimizing the use of agrochemicals based on renewable resources can reduce or eliminate ecosystems and biodiversity threats. Nanochitosan as a sustainable alternative offers promising solutions for sustainable agricultural practices that work at multiple spatial and temporal scales throughout the plant growth cycle. This review focuses on the potential of nanochitosan in sustainable agricultural production and provides insights into the mechanisms of action and application options of nanochitosan throughout the plant growth cycle. We emphasize the role of nanochitosan in increasing crop yields, mitigating plant diseases, and reducing agrochemical accumulation. The paper discusses the sources of nanochitosan and its plant growth promotion, antimicrobial properties, and delivery capacity. Furthermore, we outline the challenges and prospects of research trends of nanochitosan in sustainable agricultural production practices and highlight the potential of nanochitosan as a sustainable alternative to traditional agrochemicals.

Seaweed extracts: enhancing plant resilience to biotic and abiotic stresses

Seaweeds are a natural marine resource containing many bioactive compounds such as amino acids, lipids, carbohydrates, proteins, phytohormones, and antimicrobial compounds. Since ancient times, seaweeds have been used in various sectors, including medicine, food, and the cosmetic industry. Currently, seaweeds are a promising alternative to reduce the application of harmful chemicals in agriculture. Seaweed and its derived products have been utilized for plant growth promotion, immunity enhancement, and the reduction of biotic and abiotic stresses. In the current global scenario, synthetic fertilizers and chemical pesticides are commonly used to increase agricultural crop production to meet the growing demands of the world population. However, these chemicals pose significant threats to the health of people, livestock, plants, soil, and the entire environment. In contrast, seaweed-based products are emerging as a newer option for stress mitigation and reduction, offering an alternative to synthetic chemicals. This article explains the use of seaweed extracts to increase the tolerance of plants to biotic and abiotic stresses. We also address the functions of various bioactive compounds present in seaweed extracts and the mechanisms by which they promote plant growth and induce defense against different stresses.

Response of Typical Shrubs Growth and Soil Nutrients to Graphene Addition in Impoverished Land of the Ulan Buh Desert

Graphene can promote plant growth and improve soil conditions, but its effectiveness in enhancing infertile soils in arid regions remains unclear. This study selected three typical shrubs from the Ulan Buh Desert Nitraria tangutorum, Xanthoceras sorbifolium, and Amygdalus mongolica as research subjects. Five graphene addition levels were set: 0 mg/L (C0), 25 mg/L (C1), 50 mg/L (C2), 100 mg/L (C3), and 200 mg/L (C4).A pot experiment was conducted in June 2023 to investigate the effects of graphene addition on shrub growth and soil nutrients. The results showed that the optimal graphene addition levels for A. mongolica, X. sorbifolium, and N. tangutorum were C2, C2, and C3, respectively. Compared with the control, the total biomass of the different shrubs increased by 185.31%, 50.86%, and 161.10%, respectively. However, when the graphene addition exceeded the optimal level, shrub biomass showed a decreasing trend with increasing graphene concentration. Total shrub biomass was positively correlated with soil available nitrogen and potassium, while redundancy analysis indicated that soil organic matter was the primary factor influencing shrub growth. This suggests that graphene promotes shrub growth by affecting soil organic matter and available nutrients. Therefore, graphene addition can enhance soil fertility in barren lands in arid regions and significantly promote shrub growth. However, due to soil leaching effects, this growth-promoting effect may decrease over time.

Effects of grazing and vegetation on Daurian Pika populations in northern Mongolia

Abstract Daurian Pika (Ochotona dauurica) are steppe-dwelling burrowing mammals with the potential to have large effects on central Asian grasslands due to their extensive range, propensity to occur at extremely high density, and roles as ecosystem engineers and important prey species. The few studies that have been done are mostly from northern China and Russia, while little research has been done in the majority of their range in Mongolia. We studied a population of Daurian Pika in the Darhad Valley of northern Mongolia, near the southern edge of the permafrost, where climate change is progressing rapidly. We evaluated pika populations at 87 random plots across a large 40 × 125 km area and assessed the impact of factors related to vegetation cover, grazing, and soils that predicted their occupancy and an index of their density (number of active burrows). We found that pikas were more likely to occur in areas with taller grass and higher forb cover, and burrow densities were higher in areas with low or moderate grazing and lower soil moisture. In summer, pikas mainly foraged on grass compared with forbs—while in fall, forbs appeared to be selected for in haypiles. Dense pika burrow systems had taller grasses and forbs in their immediate vicinity, suggesting that in some cases, pika could help promote plant growth for other grazers. Long-tailed Ground Squirrel (Urocitellus undulatus) was the second most abundant small mammal in our study sight and selected for areas with high cover of overgrazing indicator species and for short forbs, providing little evidence for competition with Daurian Pika. Our results suggest that shorter grass (~1 cm) can decrease pika occupancy by 75%, while heavy grazing may decrease burrow density by 66% in dry soils. With grazing pressure in Mongolia increasing dramatically since the 1990s, future research is strongly needed to assess the impacts of grazing on this keystone species.

Synthetic communities derived from the core endophytic microbiome of hyperaccumulators and their role in cadmium phytoremediation.

Although numerous endophytic bacteria have been isolated and characterized from cadmium (Cd) hyperaccumulators, the contribution and potential application of the core endophytic microbiomes on facilitating phytoremediation were still lack of intensive recognition. Therefore, a 2-year field sampling in different location were firstly conducted to identify the unique core microbiome in Cd hyperaccumulators, among which the representative cultivable bacteria of different genera were then selected to construct synthetic communities (SynComs). Finally, the effects and mechanisms of the optimized SynCom in regulating Cd accumulation in different ecotypes of Sedum alfredii were studied to declare the potential application of the bacterial agents based on core microbiome. Through an innovative network analysis workflow, 97 core bacterial taxa unique to hyperaccumulator Sedum was identified based on a 2-year field 16S rRNA sequencing data. A SynCom comprising 13 selected strains belonging to 6 different genera was then constructed. Under the combined selection pressure of the plant and Cd contamination, Alcaligenes sp. exhibited antagonistic relationships with other genera and plant Cd concentration. Five representative strains of the other five genera were further conducted genome resequencing and developed six SynComs, whose effects on Cd phytoremediation were compared with single strains by hydroponic experiments. The results showed that SynCom-NS comprising four strains (including Leifsonia shinshuensis, Novosphingobium lindaniclasticum, Ochrobactrum anthropi, and Pseudomonas izuensis) had the greatest potential to enhance Cd phytoremediation. After inoculation with SynCom-NS, genes related to Cd transport, antioxidative defense, and phytohormone signaling pathways were significantly upregulated in both ecotypes of S. alfredii, so as to promote plant growth, Cd uptake, and translocation. In this study, we designed an innovative network analysis workflow to identify the core endophytic microbiome in hyperaccumulator. Based on the cultivable core bacteria, an optimized SynCom-NS was constructed and verified to have great potential in enhancing phytoremediation. This work not only provided a framework for identifying core microbiomes associated with specific features but also paved the way for the construction of functional synthetic communities derived from core microbiomes to develop high efficient agricultural agents. Video Abstract.

Exploring Plant–Bacterial Symbiosis for Eco-Friendly Agriculture and Enhanced Resilience

This review explores the intricate relationship between plants and bacterial endophytes, revealing their multifaceted roles in promoting plant growth, resilience, and defense mechanisms. By selectively shaping their microbiome, plants harness diverse endophytic bacterial strains to enhance nutrient absorption, regulate hormones, mitigate damage, and contribute to overall plant health. The review underscores the potential of bacterial endophytes in self-sustaining agricultural systems, offering solutions to reduce reliance on fertilizers and pesticides. Additionally, the review highlights the importance of endophytes in enhancing plant tolerance to various environmental stresses, such as drought, salinity, extreme temperatures, and heavy metal toxicity. The review emphasizes the significance of understanding and harnessing the mutualistic relationship between plants and endophytes for maximizing agricultural yields and promoting sustainable farming practices.

Cyanobacteria's power trio: auxin, siderophores, and nitrogen fixation to foster thriving agriculture.

Cyanobacteria, often overlooked in traditional agriculture, are gaining recognition for their roles in enhancing plant growth and soil health through diverse mechanisms. This review examines their multifaceted contributions to agricultural systems, highlighting their proficiency in auxin production, which promotes plant growth and development. Additionally, we examined cyanobacteria's ability to produce siderophores that enhance iron absorption and address micronutrient deficiencies, as well as their capacity for nitrogen fixation, which converts atmospheric nitrogen into a form that plants can utilize, all with the goal of reducing reliance on synthetic fertilizers. A meta-analysis of existing studies indicates significant positive effects of cyanobacteria on crop yield, although variability exists. While some research shows considerable yield increases, other studies report non-significant changes, suggesting benefits may depend on specific conditions and crop types. The overall random-effects model estimate indicates a significant aggregate effect, with a few exceptions, emphasizing the need for further research to optimize the use of cyanobacteria as biofertilizers. Although cyanobacteria-based products are limited in comparison to seaweed-derived alternatives, for instance, ongoing challenges include regulatory issues and production costs. Integrating cultivation with wastewater treatment could enhance competitiveness and viability in the agricultural market.

Metal-organic framework-based dual function nanosystems for aluminum detoxification and plant growth in acidic soil.

Plants encounter various abiotic stresses throughout growth and development, with aluminum stress emerging as a major global agricultural challenge that hinders plant growth and limits crop yields in acidic soils. In this study, nanomaterials with dual functions, controlled release and adsorption, were constructed to alleviate aluminum toxicity. Specifically, two metal-organic frameworks, UiO-66 and ZIF-8, were used to load naphthylacetic acid and tryptophan, respectively. These two controlled-release systems were then combined with a chitosan-based matrix (NT@CS@UZ) to enable the regulated release of both compounds at distinct rates. Concurrently, the porous structure of these materials facilitates the adsorption of soluble aluminum in the plant rhizosphere. Results show that the acidic environment accelerates ZIF-8 degradation, triggering an early release of tryptophan under aluminum stress conditions. This early release promotes plant growth and alleviates stress damage. Naphthylacetic acid is subsequently released at a slower, sustained rate to stimulate root growth and further mitigate aluminum toxicity in roots. Additionally, NT@CS@UZ effectively adsorbs aluminum ions, limiting Al3+ uptake by plants and creating a low-aluminum barrier to protect roots. These dual function nanomaterials significantly boost crop yield and enhance stress resilience, presenting new avenues for food security and sustainable agricultural practices.

Endophytic Bacterial Community, Core Taxa, and Functional Variations Within the Fruiting Bodies of Laccaria

Macrofungi do not exist in isolation but establish symbiotic relationships with microorganisms, particularly bacteria, within their fruiting bodies. Herein, we examined the fruiting bodies’ bacteriome of seven species of the genus Laccaria collected from four locations in Yunnan, China. By analyzing bacterial diversity, community structure, and function through 16S rRNA sequencing, we observed the following: (1) In total, 4,840,291 high-quality bacterial sequences obtained from the fruiting bodies were grouped into 16,577 amplicon sequence variants (ASVs), and all samples comprised 23 shared bacterial ASVs. (2) The Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium complex was found to be the most abundant and presumably coexisting bacterium. (3) A network analysis revealed that endophytic bacteria formed functional groups, which were dominated by the genera Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Novosphingobium, and Variovorax. (4) The diversity, community structure, and dominance of ecological functions (chemoheterotrophy and nitrogen cycling) among endophytic bacteria were significantly shaped by geographic location, habitat, and fungal genotype, rather than fruiting body type. (5) A large number of the endophytic bacteria within Laccaria are bacteria that promote plant growth; however, some pathogenic bacteria that pose a threat to human health might also be present. This research advances our understanding of the microbial ecology of Laccaria and the factors shaping its endophytic bacterial communities.

Cotton-mycorrhizal symbiosis: a comprehensive review of benefits for sustainable agriculture

Abstract Fertilizers and plant protection chemicals have played crucial role in modern agriculture. However, their excessive and imbalanced use over decades has resulted in the degradation and deterioration of soil health. The sustainability of agricultural systems largely depends on improving soil health. In this context, the arbuscular mycorrhizal fungi (AMF) association is a well-known interaction among plant microbial symbiotic associations that plays a multifunctional role in maintaining plant-soil health. More than 90% of terrestrial crop plants, including cultivated cotton, have a mutualistic symbiotic association with AMF. Symbiosis provides several benefits, such as the acquisition of mineral nutrients (primarily phosphorus), protection against biotic and abiotic stresses, and improved yield and fiber quality, contributing to the growth and development of the host plant. Under controlled conditions, the percent root length colonization of cotton was 50 to 70%, indicating the potential of AMF as a biological agent and plant growth promoter for sustainable cotton production. This review provides an updated and comprehensive overview of cotton-mycorrhizal symbiosis and its benefits.

Pros and Cons of Different Irrigation Scheduling Approaches: A Review

Scheduling irrigation involves making a decision of how much water to apply and when. Three factors enter into the decision: water needs of the plants, water availability, and storing capacity of the soil around the roots. When to irrigate should be greatly influenced by water needs of the plants. Irrigation scheduling (IS) aims to give plants the right amount of water at the right times in order to promote plant growth and achieve high yield and/or quality. The four most popular ways of operating irrigation scheduling includes: evapotranspiration and water balance (ET-WB), soil moisture status, plant water status, and models based irrigation scheduling. When the four types of irrigation scheduling systems are thoroughly examined, it becomes clear that they are all centered on soil moisture, which serves as a link or bridge between crop water needed for growth and irrigation management). A few studies have been accomplished on pros and cons of different irrigation scheduling approaches. The purpose of this review was to provide some information on pros and cons of four selected irrigation scheduling methods, viz: evapotranspiration and water balance (ET-WB), soil moisture status, plant water status, and models based irrigation scheduling. When the four types of irrigation scheduling systems are thoroughly examined, it becomes clear that they are all centered on soil moisture, which serves as a link or bridge between crop water needed for growth and irrigation management. Plant-based techniques can need professional oversight since farmers may find it difficult to understand the tracked data, which reduces the dependability of irrigation. When built software or a procedure is based on a well-calibrated model, model-based methods are simpler for users. When compared to the soil moisture sample irrigation scheduling approach, the evapotranspiration losses irrigation scheduling method uses less irrigation water regardless of the minimal yield difference.

Bacterial diversity in rice field soil and sludge soil samples: A comparative metagenomics-based study

Abstract Soil contains several organic and inorganic substances. It also has a large number of microbial diversity including bacteria. This microbial community affects the physicochemical properties of soil. This bacterial bacteria diversity is also involved in biomass degradation and plant growth promotion. Metagenomic sequencing is used to analyze microbial diversity in environmental samples. The metagenomic profiling of bacterial populations in the sludge and rice field soil was done at phylum, class, order, family, genus, and species levels. The metagenomic study revealed that Proteobacteria, Bacteroidetes, Chloroflexi, Acidobacteria and other unknown bacteria were reported in 16S rRNA Illumina MiSeq in the sludge and rice soil samples. We compared the taxonomic classification of bacterial diversity found in sewage soils with that of rice field soils using metagenomic sequencing analysis of the V3-V4 region of the 16S rRNA. In rice soil, the most abundant group was Proteobacteria followed by Chloroflexi, Acidobacteria, Actinobacteria, and Bacteroidetes which increase the soil nutrient and influence the production of the plant. Bacteroidetes are the most dominant group in sludge soil than rice soil. Consequently, the core microbiome analysis indicated that Sorangium, Geobacter, Azoarcus, and Anaeromyxobacter bacterial genera were more abundant in both soil samples.

Complete genome of Variovorax sp. EBFNA2, isolated from a surface-sterilized fava bean nodule.

We report the complete genome sequence of Variovorax sp. EBFNA2, a fava bean nodule endophyte. The strain appears to be a new species, and its genome provides insight into its interactions with host plants and potential to promote plant growth and crop yield.

Decoding the Impact of a Bacterial Strain of Micrococcus luteus on Arabidopsis Growth and Stress Tolerance

Microbes produce various bioactive metabolites that can influence plant growth and stress tolerance. In this study, a plant growth-promoting rhizobacterium (PGPR), strain S14, was identified as Micrococcus luteus (designated as MlS14) using de novo whole-genome assembly. The MlS14 genome revealed major gene clusters for the synthesis of indole-3-acetic acid (IAA), terpenoids, and carotenoids. MlS14 produced significant amounts of IAA, and its volatile organic compounds (VOCs), specifically terpenoids, exhibited antifungal activity, suppressing the growth of pathogenic fungi. The presence of yellow pigment in the bacterial colony indicated carotenoid production. Treatment with MlS14 activated the expression of β-glucuronidase (GUS) driven by a promoter containing auxin-responsive elements. The application of MlS14 reshaped the root architecture of Arabidopsis seedlings, causing shorter primary roots, increased lateral root growth, and longer, denser root hairs; these characteristics are typically controlled by elevated exogenous IAA levels. MlS14 positively regulated seedling growth by enhancing photosynthesis, activating antioxidant enzymes, and promoting the production of secondary metabolites with reactive oxygen species (ROS) scavenging activity. Pretreatment with MlS14 reduced H2O2 and malondialdehyde (MDA) levels in seedlings under drought and heat stress, resulting in greater fresh weight during the post-stress period. Additionally, exposure to MlS14 stabilized chlorophyll content and growth rate in seedlings under salt stress. MlS14 transcriptionally upregulated genes involved in antioxidant defense and photosynthesis. Furthermore, genes linked to various hormone signaling pathways, such as abscisic acid (ABA), auxin, jasmonic acid (JA), and salicylic acid (SA), displayed increased expression levels, with those involved in ABA synthesis, using carotenoids as precursors, being the most highly induced. Furthermore, MlS14 treatment increased the expression of several transcription factors associated with stress responses, with DREB2A showing the highest level of induction. In conclusion, MlS14 played significant roles in promoting plant growth and stress tolerance. Metabolites such as IAA and carotenoids may function as positive regulators of plant metabolism and hormone signaling pathways essential for growth and adaptation to abiotic stress.

Particle size is an important factor influencing the effects of biochar return to woodland soils: An evaluation from the perspective of sapling growth and soil microbial carbon processes

Biochar can increase ecosystem carbon sequestration by promoting plant growth and stabilizing soil organic carbon (SOC). Biochar produced from forest waste typically varies in particle size and is frequently applied directly for soil enhancement without pulverization. The effects of different biochar particle sizes on sapling growth, woodland soil properties and microbial carbon processes are unclear. This study used field experiments to compare the effects of different biochar particle sizes on sapling growth and microbial metabolic entropy (qCO2). The impacting mechanisms were explored by examining soil physicochemical properties, enzyme activity, and microbial community structure. The application of forest waste (FW) and small particle biochar (SPBC, particle size<2 mm) did not significantly affect sapling growth. Conversely, middle particle biochar (MPBC, particle size 2–10 mm) and large particle biochar (LPBC, particle size>10 mm) reduced sapling biomass by 20.76% and 38.87%, respectively, compared to SPBC. MPBC and LPBC applications resulted in soil nutrient loss (total nitrogen and available phosphorus), inhibiting sapling growth. After 167 days, qCO2 rankings were as follows: FW (30.37 ± 5.18) (P<0.05)> LPBC (20.91 ± 3.62) > CK (16.21 ± 2.71) > MPBC (15.99 ± 3.54) > SPBC (7.8 ± 0.80) (P < 0.05). The rankings of organic carbon retention rates rankings were as follows: SPBC (85.14%) > LPBC (70.35%) > FW (67.31%) > CK (54.53%) > MPBC (51.96%). SPBC increased biochar-soil-microbe interactions, raised the relative proportion of k/r-strategy bacteria, reduced extracellular cellulase activity thus inhibit qCO2. In conclusion, small particle biochar (<2 mm), compared to larger-particle biochar, improves SOC sequestration without negatively affecting sapling growth. Therefore, particle size should be considered as a management indicator for biochar applications in artificial forest practices.

Harnessing Biocontrol Potential of Streptomyces rochei Against Pythium aphanidermatum: Efficacy and Mechanisms.

Tomato (Solanum lycopersicum) and chilli (Capsicum annuum) are globally significant vegetable crops susceptible to damping-off disease caused by Pythium aphanidermatum, leading to substantial yield losses. The study aimed to document the biocontrol and plant growth promotion potential of Streptomyces rochei against damping-off disease in tomato and chilli. The actinobacterial isolates ACS18 followed by ACT30, and AOE12 were accomplished as the most effective antagonists against P. aphanidermatum in vitro. Molecular characterization confirmed these isolates as members of Streptomyces genus, with ASH 18 the top performer identified as S. rochei isolate. Analysis of biomolecule through GC-MS during ditrophic interaction between pathogen and S. rochei showed the presence of various antifungal metabolites which were directly related to suppression of the pathogen. Subsequently, S. rochei was formulated into a talc-based preparation and used as seed treatment and soil application against damping-off. In greenhouse trials, significant reductions in damping-off incidence were observed, Furthermore, seedlings treated with S. rochei displayed enhanced root and shoot lengths compared to the uninoculated controls. These benefits potentiate S. rochei as a promising biocontrol agent and demonstrating its dual benefits of disease suppression and promotion of seedling growth.