Plant Growth Research Articles

Cocultivos de microorganismos endófitos: Estrategia para la producción de bioestimulantes y compuestos de valor agregado

Cocultures between algae and bacteria aim to harness the metabolic capabilities of both microorganisms for biotechnological purposes. However, establishing a successful coculture is challenging because of their different nutritional and environmental requirements. This work proposes the establishment of a coculture between the plant growth-promoting bacterium Methylobacterium oryzae and the unicellular green alga Coccomyxa simplex, both endophytes of Vachellia farnesiana, with the aim of using their metabolic capacities to produce value-added compounds. To achieve this, the conditions to obtain a stable alga-bacteria coculture were defined, and the effect of the coculture and the initial nutrient concentration on lipid and pigment production, as well as plant growth stimulation were evaluated. A stable coculture was successfully established enabling the growth of both microorganisms even in the absence of carbon and nitrogen sources. The coculture stimulated lipid production (up to 43%) and pigment production (by 2.5 to 4.8 times). Additionally, the coculture's supernatant improved the growth of radish seedlings, suggesting that the coculture promotes the production of biostimulant compounds with potential to enhance crop yields and reduce the use of chemical fertilizers.

Classroom data science: data and dataing for making sense of multivariate plant growth

Abstract What is considered data and how it is communicated publicly is rapidly changing. Participation in society involves multiple opportunities to engage with complex statistical concepts in media, in personal health, and regarding climate change. Children also are engaging with evolving data types in social media interactions and in educational contexts where they are the data. Yet little time is spent in classrooms supporting children to explore and make their own data decisions about various data types. This study investigates the role that fourth graders’ use of graphing conventions played in supporting their conceptual development of: non-traditional data and dataing during one lesson. The author hopes to contribute a new perspective in conceptualising dataing as enculturating statistical practices around data that involves multiple features, to communicate key information, involving tools for engaging with statistics to communicate a story. In this case study, a video clip presented an entrance point in exploring multivariate data (multiple variables). Video observation and student graphs revealed insights into children’s data and dataing experiences and processes involved with multivariate data, supported by a classroom culture that valued statistical processes as a creative and meaningful, story-telling endeavour. When students were tasked with representing plant growth using a graph, displays included a wide range of variables such as patterns of leaf growth and qualitative stages of plant growth. Engaging with multivariate data in exploratory ways supported students in this study to play with graphing conventions, establishing local mathematical practices involving non-traditional data.

Growing Degree Day Climatology in Aydın, Türkiye

Plants need to accumalate heat to complete a particular or whole growth period. This accumalation depends on temperature thresholds above or below which plant growth ceases, and on air temperature. It can be speculated that more heat accumulation is available for plants due to rapid warming within three or four decades. This study presents more recent heat accumulation for plants, quantified using a useful index called growing degree day (GDD), for five locations (Söke, Kuşadası, Aydın, Sultanhisar and Nazilli) in Aydın, Türkiye, during the latest climatic normal period from 1991 to 2020. GDD values were calculated both in monthly basis from March through October, and in daily basis from March 1st to October 31st. Monthly GDD averages, as expected, showed a pattern that increased from March to July or August, then decreased thereafter till October. Range and standart deviation showed approximately an opposite pattern, suggesting higher uncertainity in relatively colder months. The results are expected to provide farmers or agricultural practitioners with the latest averages of GDD to predict plant growth and development.

Mitigating soil compaction and enhancing corn (Zea mays L.) growth through biological and non-biological amendments

Soil compaction is a pressing issue in agriculture that significantly hinders plant growth and soil health, necessitating effective strategies for mitigation. This study examined the effects of sugarcane bagasse, both in its raw form and as biochar, along with biological activators (Bacillus simplex UTT1 and Phanerochaete chrysosporium) on soil characteristics and corn (Zea mays L.) plant biomass in a compacted soil. Using a completely randomized factorial design, we assessed their impact on soil bulk density, porosity, nutrient concentrations, and plant growth parameters. Results indicated that combining organic amendments with microbial inoculation (B. simplex UTT1 + P. chrysosporium) significantly reduced soil bulk density (7–14%) (p < 0.05) and enhanced soil aggregate stability (38%), soil permeability coefficient (52%), and total porosity (40%) (p < 0.01) compared to controls. Notably, the application of biochar and microbial inoculants improved soil moisture retention (p < 0.05) and soil nutrient availability, particularly potassium and phosphorus, which increased by 18% and 23%, respectively. Plant biomass responses (10–35%) varied, with combined microbial treatments (B. simplex UTT1 + P. chrysosporium) yielding optimal outcomes (p < 0.01) compared to individual applications. The study emphasizes that integrating organic amendments with biological processes not only mitigates soil compaction but also fosters soil health and productivity. These findings support the need for sustainable agricultural practices, highlighting the role of effective resource management in enhancing soil structure and crop yields. Future research should focus on understanding the underlying mechanisms of these interactions and their long-term implications for soil health and agricultural sustainability.Clinical trial number Not applicable.

Biochar-microplastics interaction modulates soil nitrous oxide emissions and microbial communities

Biochar has been proposed as a soil amendment in vegetable fields, where the widespread use of plastic film leads to significant retention of microplastics (MPs) in the soil. However, the interactive effect of biochar and MPs on plant growth and soil functions remains poorly understood. Here, we conducted a pot experiment to examine the effects of biochar application in the presence of conventional and biodegradable microplastics (0.05% w/w) on the growth of coriander, soil nitrogen (N) cycling processes, and microbial communities. The results showed that biochar application increased aboveground biomass by increasing plant available N of NH4+, regardless of the presence of MPs. Biochar also significantly reduced soil nitrous oxide (N2O) emissions by an average of 16% without MPs. However, when MPs were present, the effect of biochar on N2O emissions was lessened depending on the MP type. Polylactic acid consistently reduced soil N2O emissions and the abundance of N2O production genes, irrespective of biochar application. Conversely, polyethylene without biochar reduced N2O emissions primarily by inhibiting N-related functional genes responsible for nitrification and denitrification. This inhibitory effect was reversed when biochar was applied, leading to a 26% increase in N2O emissions due to increased nifH and nirK gene abundance. Although biochar and MPs did not significantly alter microbial α-diversity, they altered the composition and structure of bacterial and fungal communities, linked to changes in soil N turnover. Our study underscores the critical role of MP type in assessing the effects of biochar on soil N cycling and N2O emissions. Consequently, plastic pollution may complicate the ability of biochar to improve plant growth and soil functions, depending on the characteristics of the MPs.Graphical

EFFECTS OF LIGHT AT DIFFERENT DISTANCES AND POWER ON WHEAT (Triticum aestivum L.) AND BARLEY (Hordeum vulgare L.) GROWTH

Global population growth increases the need for efficient methods of maintaining a stable food supply. Light is one of the most important influences on plant growth and development. Artificial lighting elements used in agricultural applications have different effects on plants. This study analyzed the effects of metal halide (MH) lamps with a wavelength of 450 nm, at distances of 1, 1.5, and 2.5 m, on barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) growth. Growing occurred in light magnification rooms without daylight, using 250, 400, and 600 W MH lamps as the only light source. Plants exposed to light for 13–14 h a day were harvested after 18 days. After harvest, the amount of electrolyte leakage, chlorophyll, carotenoid, and B, Cu, Mn, Zn, K, and Ca intake were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). The data were analyzed with the SPSS 22 Statistical Package program. Wheat and barley grown at different light distances and intensities showed statistically significant changes in mineral element uptake and plant chlorophyll levels. This research contributes to the optimization of agricultural productivity and the understanding of the interaction between light quality and other environmental parameters.

Impact of Polystyrene Microplastics on Soil Properties, Microbial Diversity and Solanum lycopersicum L. Growth in Meadow Soils

The pervasive presence of microplastics (MPs) in agroecosystems poses a significant threat to soil health and plant growth. This study investigates the effects of varying concentrations and sizes of polystyrene microplastics (PS-MPs) on the Solanum lycopersicum L.’s height, dry weight, antioxidant enzyme activities, soil physicochemical properties, and rhizosphere microbial communities. The results showed that the PS0510 treatment significantly increased plant height (93.70 cm, +40.83%) and dry weight (2.98 g, +100%). Additionally, antioxidant enzyme activities improved across treatments for S. lycopersicum L. roots. Physicochemical analyses revealed enhanced soil organic matter and nutrient levels, including ammonium nitrogen, phosphorus, and effective potassium. Using 16S rRNA sequencing and molecular ecological network techniques, we found that PS-MPs altered the structure and function of the rhizosphere microbial community associated with S. lycopersicum L. The PS1005 treatment notably increased microbial diversity and displayed the most complex ecological network, while PS1010 led to reduced network complexity and more negative interactions. Linear discriminant analysis effect size (LEfSe) analysis identified biomarkers at various taxonomic levels, reflecting the impact of PS-MPs on microbial community structure. Mantel tests indicated positive correlations between microbial diversity and soil antioxidant enzyme activity, as well as relationships between soil physicochemical properties and enzyme activity. Predictions of gene function revealed that PS-MP treatments modified carbon and nitrogen cycling pathways, with PS1005 enhancing methanogenesis genes (mcrABG) and PS1010 negatively affecting denitrification genes (nirK, nirS). This study provides evidence of the complex effects of PS-MPs on soil health and agroecosystem functioning, highlighting their potential to alter soil properties and microbial communities, thereby affecting plant growth.

Physio-biochemical and molecular mechanisms of low nitrogen stress tolerance in peanut (Arachis hypogaea L.).

Nitrogen (N) is a major plant nutrient and its deficiency can arrest plant growth. However, how low-N stress impair plant growth and its related tolerance mechanisms in peanut seedlings has not yet been explored. To counteract this issue, a hydroponic study was conducted to explore low N stress (0.1mM NO3-) and normal (5.0mMNO3-) effects on the morpho-physiological and molecular attributes of peanut seedlings. Low-N stress significantly decreased peanut plant height, leaf surface area, total root length, and primary root length after 10days of treatment. Meanwhile, glutamate dehydrogenase, glutamine oxoglutarate aminotransferase activities, chlorophyll, and soluble protein contents were substantially decreased. Impairment in these parameters further suppressed photochemical efficiency (Fv/Fm), and chlorophyll fluorescence parameters (PIABS), under low-N stress. Transcriptome sequencing analysis showed a total of 2139 DEGs were identified between the two treatments. KEGG enrichment annotation analysis of DEGs revealed that 119 DEGs related to 10 pathways, including N assimilation, photosynthesis, starch, and sucrose degradation, which may respondto low-N stress in peanuts. Combined with transcriptome, small RNA, and degradome sequencing, we found that PC-3p-142756_56/A.T13EMM (CML3) and PC-5p-43940_274/A.81NSYN (YTH3) are the main modules contributing to low N stress tolerance in peanut crops. Peanut seedlings exposed to N starvation exhibited suppressed gene expression related to nitrate transport and assimilation, chlorophyll synthesis, and carbon assimilation, while also showing improved gene expression in N compensation/energy supply and carbohydrate consumption. Additionally, low N stress tolerance was strongly associated with the miRNA.

Effectiveness of Plant-Induced Resistance Against Root-Knot Nematode Depends on the Policy of Using Inducer on the Host Plant.

This research was conducted to determine the relationship between plant defense responses and the extent of treatment applied to either the aerial parts or roots of the plant. The experimental treatments included different methods of application (spraying versus soil drenching), varying treatment areas (one-sixth, one-third, half, or all of the plant's aerial parts and roots) with SA, and infecting the plants with root-knot nematodes. Evaluation of plant growth and nematode pathogenicity indices in the greenhouse section, H2O2 accumulation rate, and phenylalanine ammonia lyase enzyme activity (in aerial parts and roots) were carried out in biochemical experiments. The results showed that treating less than one-third of the aerial parts with salicylic acid (SA) did not significantly impact plant growth or nematode pathogenicity indices. However, it did lead to a notable increase in hydrogen peroxide (H2O2) accumulation, while phenylalanine ammonia lyase (PAL) enzyme activity remained unchanged. In contrast, treating more than one-third of the aerial parts resulted in decreased nematode pathogenicity and enhanced production of defense compounds. Notably, treatments targeting the roots consistently demonstrated a more pronounced effect on nematode suppression and increased defense compound levels, emphasizing the importance of root treatment, as this is where nematodes are primarily present. Overall, the study highlights the differential impact of treatment location and extent on plant defense mechanisms and suggests that strategic targeting of either aerial or root tissues can optimize plant responses against nematode attacks.

Biopesticide transplant dips and foliar acaricide applications for control of cyclamen mite (Phytonemus pallidus) in strawberry

Cyclamen mite (Phytonemus pallidus) causes injury to new growth of strawberry plants and is difficult to control because it is protected by folded leaves and plant crowns. Since cyclamen mite is easily transferred from strawberry nurseries to fruiting fields, dipping transplants in biopesticides may reduce initial populations. However, cyclamen mite numbers at 1 and 3 months-after-planting, and yield and cyclamen mite injury to fruit in the following season did not differ among transplants immersed for 30 s in Captiva® Prime, EcoTrol® EC, Landscape Oil, SuffOil-X® or Kopa Insecticidal Soap or the untreated control. Cyclamen mite is primarily controlled with foliar applications of acaricides, but there are few registered products. In greenhouse experiments, fenazaquin and pyridaben reduced cyclamen mite numbers by more than 90% in new leaves compared to the control, similar to that of the standard abamectin. New leaf injury ratings were reduced from 1 on average (scale of 0–3; 0 = no injury) pre-application to 0.25–0.5 for fenazaquin, pyridaben, and abamectin-treated plants compared to increasing to 2 for control plants 2 weeks after application. Spiromesifen and chlorfenapyr reduced cyclamen mite numbers in folded leaves in one greenhouse experiment. In the field, all acaricides reduced cyclamen mite numbers by 90–99% at 2- and 6-weeks post-application and by 75–90% at 10 months post-application. Abamectin and pyridaben resulted in 0.5–1.0% of strawberries with cyclamen mite damage compared to 3.0% for the control. All acaricides except chlorfenapyr improved strawberry yield and size. Overall, fenazaquin, pyridaben and spiromesifen should help diversify the chemical toolbox for cyclamen mite in field strawberry.

Optimization of exogenous CeO2 nanoparticles on Pak choi (Brassica rapa L. var. chinensis) to alleviate arsenic stress

Arsenic (As) is a regulated hazardous substance that persists in the environment, causing issues related to environmental health, agriculture, and food safety. Cerium oxide nanoparticles (CeO2 NPs) are emerging sustainable solutions for alleviating heavy metal stress. However, their effectiveness and optimization for foliar application in reducing As stress, especially in Pak choi, has not been reported yet. Hence, this study aims to examine the effects of foliar application of CeO2 NPs (75,000,000, 150,000,000, and 300,000,000 ng/L) on the growth, nutrient availability, and antioxidant enzymatic activities of Pak choi plants under As stress. The findings showed that foliar application of 75,000,000 ng/L CeO2 NPs significantly increased shoot length (77.32%), root length (80.98%), and number of leaves (80.23%) as compared to control without NPs. The lowest dose of CeO2 NPs (75,000,000 ng/L) increased antioxidant enzyme activities such as peroxidase (86.10%), superoxide dismutase (81.48%), and catalase (52.07%), while significantly reducing malondialdehyde (44.02%), hydrogen peroxide (34.20%), and electrolyte leakage (43.53%). Furthermore, foliar application of 75,000,000 ng/L CeO2 NPs significantly increased the content of zinc (81.02%), copper (56.99%), iron (88.04%), manganese (68.37%), magnesium (76.83%), calcium (61.16%), and potassium (84.91%) in leaves when compared to control without NPs. The same trend was observed for shoot and root nutrient concentrations. Most importantly, 75,000,000 ng/L CeO2 NPs foliar application significantly reduced shoot As (45.11%) and root As (20.89%) concentration compared to control, providing a reassuring indication of their potential to reduce As concentration in plants. Our study’s findings are of utmost importance as they indicate that lower concentrations of foliar-applied CeO2 NPs can be more effective in enhancing crop nutrition and reducing heavy metals than higher concentrations. This article is intended to present critical issues of As contamination in agricultural soils, which imposes substantial risks to crop productivity and food security.

The molecular mechanism by which heat stress during the grain filling period inhibits maize grain filling and reduces yield

High temperatures significantly impair plant growth and development by restricting maize grain filling; however, the molecular mechanisms underlying heat stress remain poorly understood. In this study, 350 maize inbred lines were evaluated under field conditions, leading to the identification of heat-tolerant Zheng58 and heat-sensitive Qi319. The two inbred lines were exposed to controlled conditions of 30°C/20°C (optimal) and 42°C/30°C (heat stress) during the grain filling period. Heat stress significantly reduced thousand-kernel weight and seed setting rates, with Qi319 experiencing more pronounced declines. In contrast, Zheng58 showed superior performance, with a grain filling rate 48% higher and seed setting rate 57% greater than Qi319. Transcriptome analysis showed that heat stress disrupted starch biosynthesis and hormonal homeostasis, notably affecting abscisic acid and auxin pathways. Additionally, photosynthetic and transpiration rates in panicle leaves were reduced due to the downregulation of genes related to light-harvesting complexes, photosystem I subunits, and water transport. These findings highlight the critical roles of starch metabolism, hormonal regulation, and photosynthetic efficiency in heat tolerance, offering valuable insights for developing heat-resilient maize varieties to mitigate yield losses under high-temperature conditions.

Time-series transcriptome analysis reveals the cascade mechanism of biological processes following the perturbation of the MVA pathway in Salvia miltiorrhiza

Various biological processes are interconnected in plants. Transcription factors (TFs) often act as regulatory hubs to regulate plant growth and responses to stress by integrating various biological pathways. Despite extensive studies on TFs functions in various plant species, our understanding of the details of TFs regulation remains limited. In this study, clonal seedlings of Salvia miltiorrhiza were exposed to specific inhibitors for 12 h. Time-series transcriptome data, sampled hourly, were used to construct co-expression networks and gene regulatory networks (GRNs). Transcriptome dynamic analysis was utilized to capture the gene expression dynamics of various biological processes and decipher the potential molecular mechanisms that regulate these processes. The perturbation results showed the growth and development processes of S.miltiorrhiza were primarily affected at the early stage, whereas stress response-related biological processes were mainly influenced at the later stage. And there was a correlation between the series of key differentially expressed genes in terpenoid biosynthesis pathways and the topological distribution of these pathways. Furthermore, the GRNs based on TFs indicate that TFs play a crucial role in connecting various biological processes. In the cytoplasmic lysate gene regulatory module, SmWRKY48-SmTCP4-SmWRKY28 constituted a regulation hub regulating S.miltiorrhiza responses to perturbation of the MVA pathway. The regulation hub mediated various pathways, including pyruvate metabolism, glycolysis/gluconeogenesis, amino acid metabolism, and ubiquinone and other terpenoid-quinone biosynthesis.Our findings suggest that perturbation of a key biological pathway in S.miltiorrhiza has time-dependent effects on other biological processes. And SmWRKY48-SmTCP4-SmWRKY28 constitutes the regulatory hub in S.miltiorrhiza responses to perturbation of MVA pathway.

Assessment of the interaction of copper and zinc with cadmium to reduce its toxicity in heavy metal-contaminated river basin soils

Copper (Cu) and zinc (Zn) serve a dual purpose by providing essential nutrients to plants and reducing cadmium (Cd) toxicity in the soil–plant system. Using Cu and Zn to alleviate Cd toxicity could be an effective and low-cost method for rehabilitating contaminated soils. Two laboratory incubation experiments were conducted to study the interaction mechanisms between Cd and Cu, and Cd and Zn at different application levels in metal-contaminated Typic Haplaquept soil. In the first experiment, 2 g of soil were placed in wide-mouthed test tubes in duplicate, with four levels of Cd (0, 1, 2, and 5 mg kg−1) and four levels of Cu (0, 5, 10, and 20 mg kg−1) added simultaneously. The second experiment used the same levels of Cd with four levels of Zn (0, 5, 10, and 20 mg kg−1). The samples were kept at 50% field water holding capacity and incubated for 0, 7, 15, 30, and 60 days at room temperature (26 ± 1 °C). The study results showed that increasing doses of Cu or Zn significantly and consistently reduced the extractable Cd and increased the soil Cu or Zn content. Over time, a significant reduction in extractable Cd and Zn and an increase in Cu in the soil were observed. Cd concentrations exhibited a gradual decline of 71.8%, 70.2%, 69.8%, and 73.5% at Cu levels of 0, 5, 10, and 20 mg kg⁻1, and 69.2%, 69.6%, 68.0%, and 70.1% at Zn levels of 0, 5, 10, and 20 mg kg⁻1, respectively, averaging a 71.3% and 69.2% reduction over an incubation period from 0 to 60 days. The interactions of Cd with Cu, Cd with Zn, Cu with days, Zn with days, and Cd with days significantly decreased Cd and Zn and increased Cu contents in the soil. The interactions between Cd and Cu, and Cd and Zn in the soil were antagonistic, demonstrating that applying Cu and Zn to the soil effectively counteracted Cd toxicity, supporting healthy plant growth in Cd-contaminated soil. It can be useful in reducing heavy metal pollution in the soils providing a sustainable and economical approach with ramifications for the environment. Using antagonistic interaction of Cd with essential micronutrients such as Cu and Zn, it contributed to soil restoration, diminished bioavailability of toxic metals and further raised the potential for safer agricultural practices in contaminated locations.

Construing the resilience to osmotic stress using endophytic fungus in maize (Zea mays L.).

In a wake of shifting climatic scenarios, plants are frequently forced to undergo a spectrum of abiotic and biotic stresses at various stages of growth, many of which have a detrimental effect on production and survival. Naturally, microbial consortia partner up to boost plant growth and constitute a diversified ecosystem against abiotic stresses. Despite this, little is known pertaining to the interplay between endophytic microbes which release phytohormones and stimulate plant development in stressed environments. In a lab study, we demonstrated that an endophyte isolated from the Kargil region of India, a Fusarium equiseti strain K23-FE, colonizes the maize hybrid MAH 14 - 5, promoting its growth and conferring polyethylene glycol (PEG)-induced osmotic stress tolerance. To unravel the molecular mechanism, maize seedlings inoculated with endophyte were subjected to comparative transcriptomic analysis. In response to osmotic stress, genes associated with metabolic, photosynthesis, secondary metabolites, and terpene biosynthesis pathways were highly upregulated in endophyte enriched maize seedlings. Further, in a greenhouse experiment, maize plants inoculated with fungal endophyte showed higher relative leaf water content, chlorophyll content, and antioxidant enzyme activity such as polyphenol oxidase (PPO) and catalase (CAT) under 50% field capacity conditions. Osmoprotectant like proline were higher and malondialdehyde content was reduced in colonized plants. This study set as proof of concept to demonstrate that endophytes adapted to adverse environments can efficiently tweak non-host plant responses to abiotic stresses such as water deficit stress via physiological and molecular pathways, offering a huge opportunity for their deployment in sustainable agriculture.

Walnut PR10/Bet v1-like proteins interact with chitinase in response to anthracnose stress.

Walnut is a significant woody oil tree species that has been increasingly affected by anthracnose in recent years. Effective anthracnose control is crucial for walnut yield and quality, which requires a comprehensive understanding of the response mechanisms to Colletotrichum gloeosporioides. The PR10/Bet v1-like proteins are involved in defense against various disease, therefore, in this study, 7 JrBet v1s were identified from the walnut transcriptome (named JrBet v1-1~1-7), whose open reading frame (ORF) was 414~483bp in length with isoelectric point ranging from 4.96 to 6.11. These JrBet v1s were classified into three groups, with the MLP/RRP and Dicot PR-10 subfamilies each comprising three members (the largest ones), indicating that the proteins within these two subfamilies may have evolved from a shared ancestral gene within the broader PR10/Bet v1 protein family. The cis-elements in the promoters of JrBet v1s were involved in response to hormones, coercive, and plant growth metabolism. Most JrBet v1s could be significantly upregulated by walnut anthracnose, JrBet v1-1, JrBet v1-2, JrBet v1-4, and JrBet v1-6 peaked at 12 days of anthracnose stress, showing a 2.85- to 63.12-fold increase compared to the control, while JrBet v1-3, JrBet v1-5 and JrBet v1-7 peaked at 9 days, with a 3.23- to 27.67-fold increase. Furthermore, the significant corelation of the upregulation under anthracnose stress of JrBet v1s and JrChit02-1 as well as JrChit02-2, the genes encoding chitinase, suggesting that during the long process of microevolution in walnut-C. gloeosporioides interactions, walnut has developed a Bet v1-chitinase defense mechanism to counteract pathogen invasion.

Four Decades of Bacillus Biofertilizers: Advances and Future Prospects in Agriculture

Over the past four decades, Bacillus biofertilizers, which are microbial formulations based on Bacillus species, have significantly contributed to sustainable agriculture by enhancing crop growth, improving soil health, and reducing the dependency on chemical fertilizers. Bacillus species, particularly known for their ability to promote plant growth, fix nitrogen, solubilize phosphorus, and produce growth-promoting substances such as phytohormones and antibiotics, have emerged as key players in the development of eco-friendly agricultural solutions. This research utilizes bibliometric analysis based on 3,242 documents sourced from the Web of Science database to map the development, key contributions, and innovation within the field from 1985 to 2023. This study identifies exponential growth in research output, particularly from 2003 onwards, indicating a robust interest and expanding research base predominantly in China, India, and the United States. We segmented the research timeline into three distinct phases, each marked by varying growth rates and research foci. This paper presents novel insights into the geographical and institutional distributions of research, highlighting the predominant role of developing countries in advancing Bacillus-based technologies. Key research hotspots have evolved from basic applications to complex interactions involving synthetic microbial communities and advanced multi-omics techniques. Our findings demonstrate a trend towards more strategic and technologically integrated approaches to developing Bacillus biofertilizers, reflecting broader shifts towards more sustainable agricultural systems. This study not only charts historical progress, but also proposes future research trajectories aimed at enhancing the application and effectiveness of microbial fertilizers across diverse ecosystems.

Characterization of PHT Genes in ‘duli’ (Pyrus betulifolia Bunge) and Expression Analysis of PbPHTs in Response to Plant Growth Regulators, P, and Salt Stress

The phosphate transporter (PHT) family plays an important role in the uptake and transport of P elements in plants. A total of 158 PbPHTs were identified from the genome of ‘duli’ (Pyrus betulifolia Bunge) in this study, including 70 PbPHT1s, 2 PbPHT2s, 70 PbPHT3s, 12 PbPHT4s, and 4 PbPHT5s. Among the 158 PHT genes, 150 were localized to 17 ‘duli’ chromosomes. Gene duplication analysis identified 18 tandemly duplicated gene pairs. The promoter analysis showed that there were a large number of cis-acting elements related to phytohormones, growth, development, stress, and light response in PbPHTs. qRT-PCR analysis revealed that most PHT genes in ‘duli’ were highly expressed in the fruits, flowers, leaves, stems, and roots, and 15 PbPHT genes were responsive to 5 μM, 0.5 mM, 5 mM H2PO4, NaCl, GR24 (synthetic SL analog), GA3 (gibberellin 3), ABA (abscisic acid), and IAA (indole-3-acetic acid). GR24, GA3, IAA, and 5 mM KH2PO4 treatments could increase the concentration, absorption, transport, and distribution of P elements in the rhizomes and leaves of ‘duli’, but 5 μM KH2PO4, NaCl, and ABA had the opposite effect. This study therefore provides a list of PbPHT genes with substantial roles in abiotic stress response, as well as important information to understand the functional characteristics of PbPHT during ‘duli’ abiotic stress tolerance, and explores the function of PbPHTs in exogenous hormones, phosphorus, and salt stress in the future.

PROCERA interacts with JACKDAW in gibberellin-enhanced source-sink sucrose partitioning in tomato.

Proper regulation of the source-sink relationship is an effective way to increase crop yield. Gibberellin (GA) is an important regulator of plant growth and development, and physiological evidence has demonstrated that GA can promote source-sink sucrose partitioning. However, the underlying molecular mechanism remains unclear. Here, we used a combination of physiological and molecular approaches to identify the components involved in GA-enhanced source-sink sucrose partitioning in tomato (Solanum lycopersicum). GA treatment increased the sucrose export rate from source leaves and the sucrose level in young leaves (sink organ). GA-mediated enhancement of source-sink sucrose partitioning depended on SlPROCERA (SlPRO), the DELLA protein in tomato. Sucrose transporter 1 (SlSUT1) was involved in phloem sucrose loading. SlJACKDAW (SlJKD) was identified as an interaction partner of SlPRO. SlJKD negatively regulated the sucrose export rate from source leaves and could directly bind to the promoter of SlSUT1 and repress its expression, while SlPRO enhanced the transcription repression function of SlJKD. This study reveals the molecular mechanism by which GA promotes source-sink sucrose partitioning in tomato and provides potential targets for source-sink relationship optimization.

Harnessing the synergy of Urochloa brizantha and Amazonian Dark Earth microbiomes for enhanced pasture recovery

Amazonian Dark Earths (ADEs) are fertile soils from the Amazon rainforest that harbor microorganisms with biotechnological potential. This study aimed to investigate the individual and potential synergistic effects of a 2% portion of ADEs and Urochloa brizantha cv. Marandu roots (Brazil’s most common grass species used for pastures) on soil prokaryotic communities and overall soil attributes in degraded soil. We conducted a comprehensive plant succession experiment in the greenhouse, utilizing vase soil samples for next-generation sequencing of 16 S rDNA, enzymatic activity assays, and soil chemical properties analysis. Univariate and multivariate analyses were performed to understand better the prokaryotic interactions within soil environments influenced by ADEs and U. brizantha roots, including differential abundance, diversity, and network analyses. Our findings reveal a complementary relationship between U. brizantha and ADEs, each contributing to distinct positive aspects of soil bacterial communities and quality. The combined influence of U. brizantha roots and ADEs exhibited synergies that enhanced prokaryotic diversity and enzyme activity. This balance supported plant growth and increased the general availability of beneficial bacteria in the soil, such as Chujaibacter and Curtobacterium while reducing the presence of potentially pathogenic taxa. This research provided valuable insights into the intricate dynamics of plant-soil feedback, emphasizing the potential for complementary interactions between specific plant species and unique soil environments like ADEs. The findings highlight the potential for pasture ecological rehabilitation and underscore the benefits of integrating plant and soil management strategies to optimize soil characteristics.