Support Plant Growth Research Articles

Assessment of Nitrogen Volatilization and Greenhouse Gas Emissions from Urea with N-stabilizer in a Productive Oil Palm Plantation (Elaeis guineensis Jacq.)

Nitrogen fertilization plays a crucial role in supporting plant growth. However, nitrogen in the soil can be lost through rainwater leaching. To address this issue, the concept of fertilizing N-stabilizer-coated urea was proposed. The aim is to reduce nitrogen loss on the field due to vaporization and minimize greenhouse gas (GHG) emissions. The study was conducted to assess the effectiveness of this N-stabilizer-coated urea in reducing nitrogen loss through vaporization, improving GHG emissions, and its impact on plant growth and leaf quality. The research was conducted at IPB-Cargill Jonggol, Bogor, West Java, oil palm education and research station from August 2021 to March 2022. The experimental design employed a completely randomized block design. The fertilizer treatments included four types of nitrogen fertilizers: urea (46% N), coated urea with N-stabilizer (46% N), ZA (21% N), and NPK (15-15-15, 15% N). Additionally, a control treatment without any fertilizer application was included. All treatments were replicated three times. Data analysis was done using the SAS (Statistical Analysis System) 9.0 program. The F-test was conducted, followed by DMRT (Duncan Multiple Range Test) advanced tests at a 5% error level. The results revealed that urea with N-stabilizer fertilization significantly reduced NH3-vaporization by 53% in the first week compared to the application of normal urea. NH3-vaporization level from ZA and NPK was < 1% compared to urea application. Field application of urea with N-stabilizer showed no significant difference in greenhouse gas emission (GHG) compared to the other nitrogen fertilizer types. The GHG values ranged from 7.10 to 7.29 g CO2-e.m-2 per day. The use of N-stabilizer-coated urea could be an effective approach to minimize nitrogen loss through vaporization and reduce greenhouse gas emissions while maintaining comparable results to other nitrogen fertilizer types in terms of GHG emissions on the field.

Characterization, fractionation and untapped potential of phosphate-amended sewage sludge biochar in soil-plant systems

Sewage sludge, a byproduct of wastewater treatment, poses serious environmental and health risks due to its content of organic contaminants, heavy metals, and pathogenic microorganisms. With the growing global production of municipal wastewater, finding effective methods for managing and disposing of sewage sludge has become increasingly urgent. Traditional methods such as land disposal, dumping, and incineration have limitations and environmental drawbacks. However, recent advancements have shown promise in the valorization of sewage sludge, particularly through pyrolysis, which converts it into biochar for use in soil amendment and pollutant mitigation. This study aims to characterize and fractionate phosphate-amended sewage sludge biochar produced at 300 °C, 400 °C, and 500 °C, and to evaluate its potential use in soil-plant systems. It examines nutrient bioavailability in soil after the addition of this biochar and its effects on plant growth. The pyrolysis process resulted in biochar with high alkalinity (7.2–11.1), ash content ranging from 56.9% to 87.3%, and significant phosphorus retention, with phosphorus concentrations increasing with pyrolysis temperature (5.35%–9.38%). Phosphorus fractionation showed a shift toward more stable fractions particularly at 500 °C. Soil incubation experiments indicated increased phosphorus availability with HCl-extractable P showing a high extraction efficiency of up to 94.95%. In plant growth experiments, the amended biochar significantly enhanced growth, with corn showing an increase of up to 28.8% and wheat showing an increase of up to 86% compared to the control in the first four weeks after emergence. These findings indicate that phosphate-amended sewage sludge biochar enhances nutrient availability and supports plant growth, providing a sustainable solution for sewage sludge management, contributing to soil improvement and carbon sequestration, thereby addressing global environmental challenges.

Soil Bacteria from the Namib Desert: Insights into Plant Growth Promotion and Osmotolerance in a Hyper-Arid Environment

The Namib Desert is characterized by a number of abiotic stresses, including high temperature, high salinity, osmotic pressure, alkaline pH, and limited water availability. In such environments, dry soils typically exhibit a low water potential, scarce nutrients, and high concentrations of dissolved ions, collectively creating a challenging habitat for microbial life. In this study, 89 bacterial isolates belonging to 20 genera were identified. Bacteria demonstrated significant osmotolerance, with some strains thriving at polyethylene glycol (PEG) concentrations exceeding 20%. Furthermore, these bacteria demonstrated halotolerance, high pH tolerance, and capacity to produce plant growth-promoting (PGP) traits under conditions of osmotic stress. Osmotolerant bacteria exhibited higher proficiency in siderophore production, potassium solubilization, and phosphorus solubilization, all of which are critical for supporting plant growth in nutrient-scarce and stressful environments, such as deserts. However, alginate production was higher in isolates that were less osmotolerant, indicating the potential for a compensatory mechanism in strains that were more sensitive. These findings highlight the complex strategies employed by desert bacteria to survive and support host plants in extreme environments. The present study not only enhances our understanding of microbial adaptations in arid ecosystems, but also provides important information for the development of potential applications for these bacteria in the reclamation of arid land and agricultural practices aimed at improving crop resilience to abiotic stress.

The Properties of Microorganisms and Plants in Soils after Amelioration

Soil, as a vital foundation of the Earth’s biosphere, supports plant growth, carbon storage, water cycling, and nutrient supply, making it a crucial resource for ensuring global food production and ecosystem health [...]

Variability of soil chemical properties and rice productivity in salt-affected soil in the north coastal rice field of Central Java, Indonesia

A coastal rice field is generally characterized by salt-affected soil and low soil quality for rice cultivation. Identifying soil chemical properties in these areas is necessary to determine soil management options for rice production. Therefore, soil samples were collected from 33 sampling points in the Wedung Sub-district of Demak Regency in the late dry season of 2021 to evaluate the variation among soil chemical characteristics in a coastline rice field. Soil samples were obtained beneath the topsoil (0-20 cm soil depth) and observed for electrical conductivity, exchangeable potassium, sodium, calcium, magnesium, and cation exchange capacity. Soils in the research field were categorized as slightly salty (0.75-2 dS m-1) to lightly salty (2.0-4.0 dS m-1) with very high sodium (>2 cmol(+) kg-1). Exchangeable potassium was dominated by moderate (0.3-0.7 cmol(+) kg-1) and low categories (0.2-0.3 cmol(+) kg-1). Based on soil calcium-to-magnesium ratios, around 6% of all samples were classified as calcium-deficient. The range of soil cation exchange capacity was 22-30 cmol(+) kg-1 and classified as high soil cation exchange capacity. Rice productivity in the salt-affected soil was around 4 t ha-1. Strategies for soil and controlling plants, such as soil amelioration and salt-tolerant rice cultivars, should be pursued to support plant growth and enhance rice productivity in the salt-affected soil, particularly in the coastal area.

New Aspects of the Effects of Climate Change on Interactions Between Plants and Microbiomes: A Review.

One of the most talked about issues of the 21st century is climate change, as it affects not just our health but also forestry, agriculture, biodiversity, the ecosystem, and the energy supply. Greenhouse gases are the primary cause of climate change, having dramatic effects on the environment. Climate change has an impact on the function and composition of the terrestrial microbial community both directly and indirectly. Changes in the prevailing climatic conditions brought about by climate change will lead to modifications in plant physiology, root exudation, signal alteration, and the quantity, makeup, and diversity of soil microbial communities. Microbiological activity is very crucial in organic production systems due to the organic origin of microorganisms. Microbes that benefit crop plants are known as plant growth-promoting microorganisms. Thus, the effects of climate change on the environment also have an impact on the abilities of beneficial bacteria to support plant growth, health, and root colonization. In this review, we have covered the effects of temperature, precipitation, drought, and CO2 on plant-microbe interactions, as well as some physiological implications of these changes. Additionally, this paper highlights the ways in which bacteria in plants' rhizosphere react to the dominant climatic conditions in the soil environment. The goal of this study is to analyze the effects of climate change on plant-microbe interactions.

Assessment of amoxicillin (AMX) removal from aqueous medium through Rhapis-based bioretention system.

Antibiotics can be effectively removed from wastewater using constructed wetlands (C.W.s). However, little is known about using attractive garden plants in C.W.s to eliminate antibiotics. Thus, the current study aims to treat amoxicillin (AMX)-contaminated wastewater through a Rhapis excelsa-based bioretention system (BS). The investigation was done at 15days hydraulic retention time (HRT) under two conditions: set-1, varied AMX 5 to 25ppm with constant NPK (nitrogen, phosphorus, potassium) source; and set-2, varied NPK sources with constant AMX (25ppm). During the study, it was observed that in the set-1 condition with increasing AMX concentration, the removal of AMX through BS decreased; however, in the set-2 experiment, with enhancing NPK source, the performance of the BS treating 25-ppm AMX-contaminated wastewater increased. AMX removal of 2.3%, 66.3%, 60.6%, 52.2%, 46.7%, and 44.9% was achieved for control, BS-1, BS-2, BS-3, BS-4, and BS-5, respectively, during set-1 experiment. However, in the set-2 experiment, 23.4% (control), 43.3% (BS-1), 60.3% (BS-2), 75.9% (BS-3), 88.8% (BS-4), and 99% (BS-5) AMX removal were achieved. Removing pollutants like AMX, COD, PO43--P, NO3--N, and NH4+-N followed first-order kinetics. A positive correlation of COD with AMX was observed through principal component analysis and correlation matrix. The microbial community study was also covered to prioritize the role of microbes in treating AMX through BSs. The AMX treatment through Rhapis excelsa-based BS supported plant growth and development with increasing chlorophyll content, fresh weight, and C, H, N value.

Hydrogeochemical evolution and heavy metal characterization of groundwater from southwestern, Nigeria: An integrated assessment using spatial, indexical, irrigation, chemometric, and health risk models

This study examines the hydrogeochemical and heavy metal parameters of groundwater in Ojo District to determine its suitability for use, potential sources, and human health implications. Ten groundwater samples were assessed, and hydrogeochemical modelling was performed via the Aquachem software. The chemical ions were in the following order: EC > (107.78–448.65 μS/cm) > TDS (182.02–320.77 mg/l) > TH (46.22–182.45 mg/l) > pH (5.55–6.35); HCO3− (64.13–125.82 mg/l) > Na+ (36.87–96.49 mg/l) > Ca2+ (47.65–58.88 mg/l) > SO42− (19.94–53.67) > NO3− (15.55–44.25 mg/l) > Cl− (20.43–27.16 mg/l) > Mg2+ (11.09–16.87 mg/l) and K+ (2.55–7.86 mg/l). The concentrations of heavy metals in groundwater were in the range of: Fe (0.11–0.27 mg/l) > Mn (0.003–0.16 mg/l) > Ni (0.05–0.12 mg/l) > Zn (0.003–0.05 mg/l) > Pb (0.001–0.03 mg/l) > As (0.001–0.005 mg/l) > Cr (0.002–0.005 mg/l) > Cd (0.001–0.003 mg/l) and Cu (0.001–0.0002 mg/l), with Pb, Mn, and Ni exceeding their allowable limits. The Schoeller and Gibbs plots revealed that the major mechanisms controlling the aquifer groundwater in Ojo region are geological rock weathering and mineralization, with a minimal influence of saltwater intrusion. The piper trilinear diagram also revealed that none of the cation was dominant while the anions were strongly dominated by HCO3− (weak acids). The hydrogeochemical facies which describes the geochemical characteristics of the groundwater were classified into 3 types; “Ca2+–Mg+–HCO3– (65 %)”, “mixing zones (30 %)”, and “Na+–K+–Cl––HCO3– (5 %)”. The hydrogeochemical modelling revealed that the groundwater is characterized by forward cation exchange, while rock–water interactions (silicate dissolution) were heavily involved in the geochemical processes. The single pollution index showed that Pb, Ni, and Mn contributed significantly to contamination, and the multi–pollution indices showed that the groundwater was slightly-moderately polluted. The integrated groundwater quality index revealed that only 10 % were clean, 50 % were poor or moderately unclean, 30 % were highly unclean, and only 10 % were extremely unclean (unfit for utilization). The water pollution index showed that 70 % of the groundwater was good. The irrigation indices suggest that the groundwater would enhance soil quality and support plant growth. Multivariate analysis revealed that the groundwater is being influenced by geogenic factors and anthropogenic activities. The health risk assessment (Hazard Quotient and Hazard Index) showed that exposure of adults to the investigated groundwaters could result in noncarcinogenic adverse effects. The cancer risk values also exceeded the minimum limit (1.0 x 10−6) and thresholds (1.0 x 10−4) for adults, indicating the carcinogenic potential of the groundwater.

Phytomanagement of cadmium using Tagetes erecta in greenhouse and field conditions

Greenhouse and field studies investigated the phytoextraction potential of soil cadmium (Cd) by Tagetes erecta L., a popular ornamental flower in Asia. The effects of organic fertilizer, cattle manure, and pig manure in supporting plant growth and enhancing Cd uptake were also examined. Plants grown in soil supplemented with pig manure produced greatest biomass (12.8 ± 1.6 and 11.8 ± 0.9 g plant−1 in greenhouse and field experiments, respectively). Plant parts accumulated Cd in the order: shoot > root > flower in all treatments. Furthermore, T. erecta had a high phytoextraction potential as evidenced by translocation factors and enrichment coefficients > 1 for shoots. Marigolds cultivated in Cd-contaminated soil supplemented with organic fertilizer (CdOrg) exhibited Cd concentrations in flowers below the Maximum Permissible Level for consumption (< 0.2 mg kg−1), indicating that the edible flowers pose no health risk to humans. The flowers additionally contained significant quantities of total phenolics and phenolic acids, which may indicate their potential as an indicator of Cd-initiated oxidative stress. The phenolic compounds can furthermore function as precursors for manufactured medicinal products by acting as antioxidants and antimicrobials. Application of organic fertilizer and selected organic amendments may have contributed to the greater concentrations of phenolics. The Cd alone treatment resulted in lowest production of bioactive compounds and antioxidant capacity. It is proposed that T. erecta be applied for Cd phytoextraction while enhancing local economies as an ornamental species, and for plant extracts for application of bioactive compounds and antioxidant capacity.

Enhancing cadmium phytoremediation in contaminated soil using sunflower (Helianthus annuus L.) with EDTA and vermicompost amendments

The study hypothesis posits that EDTA, an effective chelating agent, can effectively mobilize cadmium from soil, augmenting the sunflower's natural ability to absorb and sequester heavy metals. Concurrently, vermicompost, rich in organic matter and beneficial microorganisms, enhances soil health and supports plant growth, thereby fortifying the sunflower's phytoremediative potential. The pot experiment was carried out as an overall completely randomized design (CRD) at the Sheila Dhar Institute (SDI) experimental farm, University of Allahabad, Prayagraj, in the Kharif season during the years 2023-2024. Plants were cultivated in pots with soil (5 kg) that contained varying concentrations of Cd (0, 15, 30, and 50 mg/kg), vermicompost (0 and 10 g/kg), and EDTA (0 and 2.5 mmol/kg). Plants were also cultivated in containers with clean soil (T1) as control treatment. For analyzed heavy metal (Cd) in plants with a tri-acid mixture (15 ml) containing concentrations of HNO3, H2SO4, and HClO4 in 5:1:2 ratios, use the Atomic Absorption Spectrophotometer (AAS). The result showed that the combined Treatment (T3) pot of application of Cd 0+ EDTA (2.5 mmol/kg) and vermicompost (10 g/kg) was the maximum dry biomass (14.43 g/pot) of the sunflower plant. While the maximum dose combined treatment (T12) application of Cd 50 mg/kg+ EDTA 2.5 mmol/kg and vermicompost 10 g/kg is greater than before, the maximum accumulation of Cd in the shoot and root of Helianthus annuus L. by shoot 37.16% and root 31.16%, respectively as compared to the control treatment pot Cd-50. The results indicate that the combined application of EDTA and vermicompost significantly increased cadmium uptake by sunflowers compared to untreated controls, demonstrating their synergistic effect in improving phytoremediation efficiency.

Machine Learning Modelling for Soil Moisture Retrieval from Simulated NASA-ISRO SAR (NISAR) L-Band Data

Soil moisture is a critical factor that supports plant growth, improves crop yields, and reduces erosion. Therefore, obtaining accurate and timely information about soil moisture across large regions is crucial. Remote sensing techniques, such as microwave remote sensing, have emerged as powerful tools for monitoring and mapping soil moisture. Synthetic aperture radar (SAR) is beneficial for estimating soil moisture at both global and local levels. This study aimed to assess soil moisture and dielectric constant retrieval over agricultural land using machine learning (ML) algorithms and decomposition techniques. Three polarimetric decomposition models were used to extract features from simulated NASA-ISRO SAR (NISAR) L-Band radar images. Machine learning techniques such as random forest regression, decision tree regression, stochastic gradient descent (SGD), XGBoost, K-nearest neighbors (KNN) regression, neural network regression, and multilinear regression were used to retrieve soil moisture from three different crop fields: wheat, soybean, and corn. The study found that the random forest regression technique produced the most precise soil moisture estimations for soybean fields, with an R2 of 0.89 and RMSE of 0.050 without considering vegetation effects and an R2 of 0.92 and RMSE of 0.042 considering vegetation effects. The results for real dielectric constant retrieval for the soybean field were an R2 of 0.89 and RMSE of 6.79 without considering vegetation effects and an R2 of 0.89 and RMSE of 6.78 with considering vegetation effects. These findings suggest that machine learning algorithms and decomposition techniques, along with a semi-empirical technique like Water Cloud Model (WCM), can be effective tools for estimating soil moisture and dielectric constant values precisely. The methodology applied in the current research contributes essential insights that could benefit upcoming missions, such as the Radar Observing System for Europe in L-band (ROSE-L) and the collaborative NASA-ISRO SAR (NISAR) mission, for future data analysis in soil moisture applications.

Effect of the residual levofloxacin on hydroponic vegetables with sewage treatment plant tailwater: Microbial community, discharge risk and control strategy

Tailwater-based hydroponic vegetable is a promising strategy for domestic wastewater recycling. However, the effect of residual antibiotics on the hydroponic vegetable system and the relation between hydroponic culture parameters and the residual water quality are still unclear. Here, the typical antibiotic Levofloxacin (LVFX) was employed, and the effect of LVFX (5 mg/L) on the residual water quality, plant growth and microbial community of water spinach hydroponic culture system were investigated under different hydraulic residence times (HRT). Obvious toxic effects on water spinach were observed, and the highest removal rate of LVFX (about 6 %) and TN (25.67±1.43 %) was observed when HRT was 7 days. Hydroponic culture increased the microbial abundance, diversity, and microbial community stability. To optimize the hydroponic culture, actual sewage plant tailwater spiked with 20 μg/L LVFX, along with three common planting substrates (sponge, ceramsite, and activated carbon) were used for the hydroponic culture of lettuce (seasonal reasons). The inhibition effect of LVFX on the removal of NO3--N and TN was observed even as the LVFX concentration decreased significantly (from 14.62 ± 0.44 μg/L to 0.65 ± 0.07 μg/L). The best growth situation of lettuce and removal rates of NH4+-N, NO3--N, TN, especially LVFX (up to 95.65 ± 0.54 %) were observed in the activated carbon treated group. The overall results indicate the negative effect of residual antibiotics on the hydroponic vegetable systems, and adding activated carbon as substrate is an effective strategy for supporting plant growth and controlling discharged risk.

Mitigation of salt stress in Sorghum bicolor L. by the halotolerant endophyte Pseudomonas stutzeri ISE12.

Increasing soil salinity, exacerbated by climate change, threatens seed germination and crop growth, causing significant agricultural losses. Using bioinoculants based on halotolerant plant growth-promoting endophytes (PGPEs) in modern agriculture is the most promising and sustainable method for supporting plant growth under salt-stress conditions. Our study evaluated the efficacy of Pseudomonas stutzeri ISE12, an endophyte derived from the extreme halophyte Salicornia europaea, in enhancing the salinity tolerance of sorghum (Sorghum bicolor L.). We hypothesized that P. stutzeri ISE12 would improve sorghum salt tolerance to salinity, with the extent of the increase in tolerance depending on the genotype's sensitivity to salt stress. Experiments were conducted for two sorghum genotypes differing in salinity tolerance (Pegah - salt tolerant, and Payam - salt sensitive), which were inoculated with a selected bacterium at different salinity concentrations (0, 100, 150, and 200 mM NaCl). For germination, we measured germination percentage and index, mean germination time, vigor, shoot and root length of seedlings, and fresh and dry weight. In pot experiments, we assessed the number of leaves, leaf area, specific leaf area, leaf weight ratio, relative root weight, plantlet shoot and root length, fresh and dry weight, proline and hydrogen peroxide concentrations, and peroxidase enzyme activity. Our study demonstrated that inoculation significantly enhanced germination and growth for both sorghum genotypes. The salinity-sensitive genotype (Payam) responded better to bacterial inoculation during germination and early seedling growth stages, showing approximately 1.4 to 1.8 times greater improvement than the salinity-tolerant genotype (Pegah). Payam also displayed better performance at the plantlet growth stage, between 1.1 and 2.6 times higher than Pegah. Furthermore, inoculation significantly reduced hydrogen peroxide, peroxidase activity, and proline levels in both sorghum genotypes. These reductions were notably more pronounced in Payam, with up to 1.5, 1.3, and 1.5 times greater reductions than in Pegah. These results highlight the efficacy of P. stutzeri ISE12 in alleviating oxidative stress and reducing energy expenditure on defense mechanisms in sorghum, particularly benefiting salt-sensitive genotypes. Our findings highlight the potential of the bacterial endophyte P. stutzeri ISE12 as a valuable bioinoculant to promote sorghum growth under saline conditions.

Bioactive Compounds Produced by Endophytic Bacteria and Their Plant Hosts-An Insight into the World of Chosen Herbaceous Ruderal Plants in Central Europe.

The natural environment has been significantly impacted by human activity, urbanization, and industrialization, leading to changes in living organisms and their adaptation to harsh conditions. Species, including plants, adapt to these changes by creating mechanisms and modifications that allow them to survive in harsh environments. Also, endophytes, microorganisms that live inside plants, can support plant growth and defense mechanisms in these conditions by synthesizing antimicrobial secondary metabolites. What is more, endophytes produce bioactive metabolites, including alkaloids, amines, and peptides, which play a crucial role in the relationship between endophytes and their host organisms. Endophytes themselves benefit from this by creating a stable environment for their survival and development. The aim of this review is to gain insight into endophytic bioactive metabolites from chosen synanthropic ruderal plants. Industrial activities release pollutants like heavy metals, by-products, and waste, which challenge living organisms and require adaptation. Synanthropic plants, where endophytes are abundant, are particularly valuable for their bioactive compounds, which are used in agriculture and medicine. This review presents, among others, endophytes of herbaceous ruderal plants from central Europe-Chelidonium majus L., Urtica dioica L., Plantago lanceolata L., Matricaria chamomilla L., Equisetum arvense L., Oenothera biennis L., Silybum marianum L., and Mentha piperita L.

Vertical Green Wall Systems for Rainwater and Sewage Treatment

Rainwater and sewage are important pollution sources for surface water bodies. Vertical greening systems (VGSs) are extensively employed for these wastewater treatments due to the green and sustainable characteristics, as well as their high-efficiency in pollutant (organic matter, nitrogen, and phosphorus) removal. At present, more and more VGSs are designed with green buildings, serving city ecosystems. This study provides an overview of different kinds of VGSs for rain and sewage treatment, emphasizing their types, design, mechanisms, selection of plants, and growth substrate. Plants play a crucial role in pollutant removal, and different plants usually obtain different efficiencies of water treatment. Climbing plants and ornamental plants with fast growth rates are priority selections for VGSs, including Canna lilies, Jasmine, Grape vine, Boston ivy, Pittosporum tobira, Pelargonium australe, Mentha aquatica, and Lythrum salicaria. The substrate is the most critical part of the VGS, which plays an important role in regulating water flow, supporting plant growth, promoting biofilm growth, filtering pollutants, and adsorbing nutrients. The single substrate either has a blockage problem or has a short holding time. Therefore, a number of studies have mixed the substrates and integrated the advantages of the substrates to form a complementary effect, thereby improving the overall purification efficiency and stability. Novel substrates (sand, spent coffee grounds, date seeds, coffee grinds, reed-based, etc.) are usually mixed with coco coir, light-weight expanded clay, growstone, or perlite at a certain ratio to obtain optimum treatment performance. Moreover, plants in clay show more significant growth advantages and health statuses than in zeolite or soil. Operating parameters are also significant influences on the treatment performance. This review provides theoretical and technical support for designing sustainable, environmentally friendly, and cost-effective VGSs in treating rainwater and sewage.

Plastid HSP90C C-terminal extension region plays a regulatory role in chaperone activity and client binding.

HSP90Cs are essential molecular chaperones localized in the plastid stroma that maintain protein homeostasis and assist the import and thylakoid transport of chloroplast proteins. While HSP90C contains all conserved domains as an HSP90 family protein, it also possesses a unique feature in its variable C-terminal extension (CTE) region. This study elucidated the specific function of this HSP90C CTE region. Our phylogenetic analyses revealed that this intrinsically disordered region contains a highly conserved DPW motif in the green lineages. With biochemical assays, we showed that the CTE is required for the chaperone to effectively interact with client proteins PsbO1 and LHCB2 to regulate ATP-independent chaperone activity and to effectuate its ATP hydrolysis. The CTE truncation mutants could support plant growth and development reminiscing the wild type under normal conditions except for a minor phenotype in cotyledon when expressed at a level comparable to wild type. However, higher HSP90C expression was observed to correlate with a stronger response to specific photosystem II inhibitor DCMU, and CTE truncations dampened the response. Additionally, when treated with lincomycin to inhibit chloroplast protein translation, CTE truncation mutants showed a delayed response to PsbO1 expression repression, suggesting its role in chloroplast retrograde signaling. Our study therefore provides insights into the mechanism of HSP90C in client protein binding and the regulation of green chloroplast maturation and function, especially under stress conditions.

A fungal endophyte increases plant resilience to low nutrient availabilities: a case of Fe acquisition in legumes.

Microbial inocula are considered a promising and effective alternative solution to the use of chemical fertilizers to support plant growth and productivity since they play a key role in the availability and uptake of nutrients. Here, the effect of a beneficial of a fungal root endophyte, Fusarium solani strain K (FsK), on nutrient acquisition efficiency of the legume Lotus japonicus was studied, and putative mode-of-action of the endophyte at a molecular level was determined. Plant colonization with the endophyte resulted in increased shoot and root fresh weight under Fe deficiency compared to control nutrient conditions. Plant inoculation with FsK was associated with a significant increase in macro- and micronutrient concentration in leaves at an early stage of endophyte inoculation and a replenishment of Fe content under prolonged iron starvation. The mechanistic basis of the plant growth promotion capabilities of the endophyte is exerted at the transcriptional level since we recorded changes in the expression levels of genes related to iron uptake in FsK-colonized plants under stress conditions compared to uninoculated plants. In addition, the observed changes in the ethylene biosynthesis-related genes suggest a possible implication of ethylene in the mode of action used by FsK to enhance plant response to nutrient stress conditions. Finally, we demonstrated that the endophyte possesses a reductive high-affinity Fe uptake system and identified a ferric reductase that was induced in planta under Fe deficiency conditions, indicating that this fungal Fe homeostasis mechanism may result in a benefit in nutrient acquisition for the plant as well.

Mitochondrial respiration is essential for photosynthesis-dependent ATP supply of the plant cytosol.

Plants rely on solar energy to synthesize ATP and NADPH for photosynthetic carbon fixation and all cellular need. Mitochondrial respiration is essential in plants, but this may be due to heterotrophic bottlenecks during plant development or because it is also necessary in photosynthetically active cells. In this study, we examined in vivo changes of cytosolic ATP concentration in response to light, employing a biosensing strategy in the moss Physcomitrium patens and revealing increased cytosolic ATP concentration caused by photosynthetic activity. Plants depleted of respiratory Complex I showed decreased cytosolic ATP accumulation, highlighting a critical role of mitochondrial respiration in light-dependent ATP supply of the cytosol. Consistently, targeting mitochondrial ATP production directly, through the construction of mutants deficient in mitochondrial ATPase (complex V), led to drastic growth reduction, despite only minor alterations in photosynthetic electron transport activity. Since P. patens is photoautotrophic throughout its development, we conclude that heterotrophic bottlenecks cannot account for the indispensable role of mitochondrial respiration in plants. Instead, our results support that mitochondrial respiration is essential for ATP provision to the cytosol in photosynthesizing cells. Mitochondrial respiration provides metabolic integration, ensuring supply of cytosolic ATP essential for supporting plant growth and development.

Response of N uptake, N-total and yield of sweet corn (Zea mays saccharata Sturt) due to fertilization with granulated solid organic fertilizer and NPK in Inceptisol soil

Sweet corn productivity is greatly influenced by proper cultivation techniques, of which fertilization is one of the main factors. Effective fertilization not only supports plant growth but also affects nutrient uptake and yield. This study aimed to evaluate the effect of granulated solid organic fertilizer and NPK fertilizer on nitrogen (N) uptake, soil N-total content, and sweet corn yield in Inceptisol soil. The research was conducted from February to June 2024 at the Experimental Field, Faculty of Agriculture, Padjadjaran University with treatments including control, NPK fertilizer, and various combinations of granular organic fertilizer and NPK. The results showed that the combination of granule organic fertilizer and NPK significantly increased nitrogen uptake and N-total content in the soil compared to the single NPK application. In addition, sweet corn yield, as measured by cob weight per plant, per plot, and per hectare, also increased significantly with the fertilizer combination treatment. This study supports the use of fertilization strategies that integrate organic and inorganic fertilizers as an effective way to increase sweet corn productivity on soils with limited fertility, such as Inceptisol. The application of a combination of 1 NPK + 1 granulated organic fertilizer was the best combination in increasing N uptake, N-total and sweet corn yield.

Political Economic Role in Natural Quality Management and its Impact on Plant Ecology: Why Arar-Juniper Plants Disappeared

Wadi-Arar is a unique region that has lost some of its most important natural features within 200 years, including plants, geographical lakes, and valleys. The study aimed to investigate the disappearance of the juniper plant, a vital species in Saudi Arabia, in recent decades. The research highlighted various factors influencing the quality of life for the juniper plant and its habitats. It sought to identify the primary factors causing changes in the natural conditions of the plant and those influencing its growth. The findings indicated a significant impact of the Suez Canal on the Arar region, the sole connection between Africa and Asia, and Europe. This influence extends beyond geopolitical factors in the surrounding area, as the existence of the Suez Canal disrupted the natural life cycle of many animal species over thousands of years of migrations and coexistence across Earth's continents. These animals previously provided natural organic fertilizer to the soil, supporting plant growth. However, due to low rainfall resulting in low natural nutrients and high salinity, the plants' viability has diminished, reflecting a history of administrative and geopolitical decisions.