Significant Reduction In Biomass Research Articles

N-Acetyl Cysteine-Decorated Nitric Oxide-Releasing Interface for Biomedical Applications.

Biomedical devices are vulnerable to infections and biofilm formation, leading to extended hospital stays, high expenditure, and increased mortality. Infections are clinically treated via the administration of systemic antibiotics, leading to the development of antibiotic resistance. A multimechanistic strategy is needed to design an effective biomaterial with broad-spectrum antibacterial potential. Recent approaches have investigated the fabrication of innately antimicrobial biomedical device surfaces in the hope of making the antibiotic treatment obsolete. Herein, we report a novel fabrication strategy combining antibacterial nitric oxide (NO) with an antibiofilm agent N-acetyl cysteine (NAC) on a polyvinyl chloride surface using polycationic polyethylenimine (PEI) as a linker. The designed biomaterial could release NO for at least 7 days with minimal NO donor leaching under physiological conditions. The proposed surface technology significantly reduced the viability of Gram-negative Escherichia coli (>97%) and Gram-positive Staphylococcus aureus (>99%) bacteria in both adhered and planktonic forms in a 24 h antibacterial assay. The composites also exhibited a significant reduction in biomass and extra polymeric substance accumulation in a dynamic environment over 72 h. Overall, these results indicate that the proposed combination of the NO donor with mucolytic NAC on a polymer surface efficiently resists microbial adhesion and can be used to prevent device-associated biofilm formation.

The Metabolism, Detrimental Effects, and Signal Transduction Mechanism of Reactive Oxygen Species in Plants under Abiotic Stress

Plants are a major source of bio based materials, and their productivity is significantly impacted by environmental adversities with the continuous deterioration of the environment. The disruption of reactive oxygen species (ROS) production and scavenging balance is a common consequence of various abiotic stresses in plants, resulting in the excessive accumulation of ROS. However, it is crucial to acknowledging the dual role of ROS, acting both as harmful substances and signaling molecules. ROS can interact with membrane proteins, initiating a chain reaction of membrane lipid peroxidation. This process leads to a decrease in membrane lipid unsaturation and fluidity, as well as an increase in membrane permeability. Inhibited enzyme activity even lead to loss of protein function, caused DNA damage and mutations, blocked DNA replication and transcription, eventually leading to cell death. This can result in significant reductions in crop yield and biomass in bio based agricultural production. ROS also played vital role in signal molecule transduction in the process of plant resistance to stress, and worked in concert with other signal molecules to induce the stress resistance genes’ expression and enhance plant resistance. Hereto, scavenging mechanism for ROS in plants is of the essence to regulate the concentration of ROS, thus determining which role ROS play. The thermal dissipation of excess light energy effectively avoids ROS production, and the enzymatic and non-enzymatic antioxidant defense systems in plants work cooperatively to clear excessive ROS. This review provides a comprehensive summary of the production pathway, detrimental effects, scavenging mechanism and signal transduction of ROS in plants under abiotic stress.

Host range characterization of Phytophthora sansomeana across corn, soybean, wheat, winter cereal rye, dry bean and oats, and an in vitro assessment of seed treatment sensitivity.

Formally described in 2009, Phytophthora sansomeana is a pathogen of increasing interest in native, agricultural, and horticulturally important plant species. The objective of this study was to elucidate the symptomatic and asymptomatic host range of P. sansomeana on six agricultural crop species commonly used in field crop rotations in Michigan. In addition, sensitivity to oomicides commonly used in seed treatments including, oxathiapiprolin, mefenoxam, ethaboxam, and pyraclostrobin was performed to aid in disease management recommendations. Plant biomass, quantity of P. sansomeana DNA in roots, and reisolations were used to assess pathogenicity and virulence of eighteen isolates of P. sansomeana on each plant species using an inoculated seedling growth chamber assay. Isolates displayed varying levels of virulence to the hosts tested. Reisolations were completed for each plant species tested, and varying quantities of P. sansomeana DNA were found within all plant species root samples. Corn, wheat, soybean, dry bean, and winter cereal rye plants were symptomatic hosts with significant reduction observed in total plant biomass. No significant reduction in total plant biomass was observed in oats, and oat roots harbored the least amount of P. sansomeana DNA. No P. sansomeana isolates were insensitive to the oomicide compounds tested with mean absolute EC50 values of 7.8 x 10-2 µg/ml for mefenoxam, 1.13 x 10-1 µg/ml for ethaboxam, 2.6 x 10-2 µg/ml for oxathiapiprolin, and 3.04 x 10-1 µg/ml for pyraclostrobin. These results suggest that common crop rotations in Michigan may not be a viable option to reduce soilborne inoculum accumulation and oomicide seed treatments should be considered for early season management of P. sansomeana.

Widespread Coral Bleaching and Mass Mortality of Reef-Building Corals in Southern Mexican Pacific Reefs Due to 2023 El Niño Warming

In May 2023, oceanic and atmospheric anomalies indicated El Niño conditions in the eastern Pacific, followed by coral bleaching in coral communities and reefs of Huatulco. We conducted surveys and sampled coral reef communities from late June to mid–August of 2023 to evaluate the intensity and extent of the changes associated with the warming event. From January of 2023, Huatulco experienced positive sea surface temperature (SST) anomalies; however, beginning in June, the high-temperature anomalies became extreme (>31 °C; ~2 °C above historical records). These high temperatures resulted in extensive coral bleaching in middle–late June and mortality from middle–late July (>50–93%). In addition, the area experienced significant reductions in echinoderm abundance and fish biomass. In 2023, severe bleaching affected coral systems in the Central Mexican Pacific, Gulf of Mexico, and Mexican Caribbean, making this the most devastating marine heatwave event, simultaneously impacting coral reefs across Mexico’s Pacific and Atlantic coasts.

Ozone risk assessment of common cypress (Cupressus sempervirens L.) clones and effects of Seiridium cardinale infection

Cupressus sempervirens is a relevant species in the Mediterranean for its cultural, economic and landscape value. This species is threatened by Seiridium cardinale, the causal agent of the cypress canker disease (CCD). The effects of biotic stressors on O3 risk assessment are unknown and a comprehensive O3 risk assessment in C. sempervirens is missing. To fill these gaps, two clones of C. sempervirens, one resistant (Clone R) and one susceptible to CCD (Clone S), were subjected to three levels of O3 (Ambient Air - AA; 1.5 × AA; 2.0 × AA) for two consecutive years in an O3-free-air controlled exposure facility and artificially inoculated with S. cardinale. Both the exposure- (AOT40) and flux-based (PODy) indices were tested. We found that PODy performed better than AOT40 to assess O3 effects on biomass and the critical level for a 4% biomass loss was 2.51 mmol/m2 POD2. However, significant O3 dose-response relationships were not found for the inoculated cypresses because the combination of middle level O3 (1.5 × AA) and inoculation stimulated a biomass growth in Clone S as hormetic response. Moreover, we found a different inter-clonal response to both stressors with a statistically significant reduction of total and belowground biomass following O3, and lower root biomass in Clone S than in Clone R following pathogen infection. In summary, Clone R was more resistant to O3, and inoculation altered O3 risk via an hormetic effect on biomass. These results warrant further studies on how biotic stressors affect O3 responses and risk assessment.

Plant growth-promoting bacteria improve the Cd phytoremediation efficiency of soils contaminated with PE–Cd complex pollution by influencing the rhizosphere microbiome of sorghum

Composite pollution by microplastics and heavy metals poses a potential threat to the soilplant system and has received increasing attention. Plant growth-promoting bacteria (PGPB) have good application potential for the remediation of combined microplastic and heavy metal pollution, but few related studies exist. The present study employed a pot experiment to investigate the effects of inoculation with the PGPB Bacillus sp. SL-413 and Enterobacter sp. VY-1 on sorghum growth and Cd accumulation under conditions of combined cadmium (Cd) and polyethylene (PE) pollution. Cd+PE composite contamination led to a significant reduction in sorghum length and biomass due to increased toxicity. Inoculation with Bacillus sp. SL-413 and Enterobacter sp. VY-1 alleviated the stress caused by Cd+PE complex pollution, and the dry weight of sorghum increased by 25.7% to 46.1% aboveground and by 12.3% to 45.3% belowground. Bacillus sp. SL-413 and Enterobacter sp. VY-1 inoculation increased the Cd content and accumulation in sorghum and improved the phytoremediation efficiency of Cd. The inoculation treatment effectively alleviated the nutrient stress caused by the reduction in soil mineral nutrients due to Cd+PE composite pollution. The composition of the soil bacterial communities was also affected by the Cd, Cd+PE and bacterial inoculation treatments, which affected the diversity of the soil bacterial communities. Network analyses indicated that bacterial inoculation regulated the interaction of rhizospheric microorganisms and increased the stability of soil bacterial communities. The Mantel test showed that the changes in the soil bacterial community and function due to inoculation with Bacillus sp. SL-413 and Enterobacter sp. VY-1 were important factors influencing sorghum growth and Cd remediation efficiency. The results of this study will provide new evidence for the research on joint plantmicrobe remediation of heavy metal and microplastic composite pollution.

Comprehensive insights into sorghum (Sorghum bicolor) defense mechanisms unveiled: Plant growth-promoting rhizobacteria in combating Burkholderia-induced bacterial leaf stripe disease

Sorghum, a vital cereal crop with significant importance in traditional human health systems, faces severe challenges from biotic stresses. This study aimed to assess the morpho-physiological variations and plant growth promoting rhizobacteria (PGPR)-induced defense mechanisms in sorghum against Burkholderia sp. infection, a well-known cause of bacterial leaf stripe disease. Also, the alterations in the leaf protein band profile of sorghum exposed to Burkholderia infection were assessed via 2-D gel electrophoresis wherein the disappearance of protein bands in diseased leaf tissues was recorded. The selected PGPR, A. chroococcum Beijerinck 1901 (MCC 2351), B. megaterium (MCC 2336), and P. fluorescens (NAIMCC B-00,340), secreted hydrogen cyanide and ammonia, and produced lytic enzymes, cellulase and amylase. When tested in-planta, Burkholderia sp., applied as a foliar spray, more profoundly impacted the growth as compared to seed coat application, resulting in significant reductions in root dry biomass, whole plant length, and total chlorophyll content by 93.9, 73.4 and 53.8 %, respectively, compared to disease-free control. Visible symptoms of bacterial leaf stripe disease like brown discoloration and necrotic lesions were observed in infected sorghum plants. Furthermore, the level of phytochemicals, proline, and malondialdehyde and antioxidants, CAT and SOD, in foliage declined significantly by 46.4, 70.2, 20.7, and 16.9 %, respectively, following inoculation with Bacillus applied as a seed coat. Additionally, Burkholderia-infected plants exhibited cellular damage, mainly in leaf tissues, as revealed by SEM and CLSM. Interestingly, the PGPR inoculation substantially enhanced the measured growth parameters of sorghum while reducing the levels of phytochemicals and antioxidants. These findings suggest that A. chroococcum, B. megaterium, and P. fluorescens, possessing biocontrol activity, can be employed as a profitable, environment and pocket-friendly approach for managing plant diseases and promoting the production of sorghum under biotic stress, thereby sufficing the human food demands.

Lytic activity of phages against bacterial pathogens infecting diabetic foot ulcers

Complications of diabetes, such as diabetic foot ulcers (DFUs), are common, multifactorial in origin, and costly to treat. DFUs are the cause of nearly 90% of limb amputations among persons with diabetes. In most chronic infections such as DFU, biofilms are involved. Bacteria in biofilms are 100–1000 times more resistant to antibiotics than their planktonic counterparts. Multidrug-resistant (MDR) Staphylococcus aureus and Pseudomonas aeruginosa infections in DFUs may require alternative therapeutic agents such as bacteriophages ("phages"). This study describes the lytic activity of phage cocktails AB-SA01 (3-phage cocktail) and AB-PA01 (4-phage cocktail), which target S. aureus and P. aeruginosa, respectively. The host range and lytic effect of AB-SA01 and AB-PA01 on a planktonic culture, single-species biofilm, and mixed-species biofilm were evaluated. In vitro testing showed that 88.7% of S. aureus and 92.7% of P. aeruginosa isolates were susceptible to AB-SA01 and AB-PA01, respectively, in the planktonic state. The component phages of AB-SA01 and AB-PA01 infected 66% to 94.3% of the bacterial isolates tested. Furthermore, AB-SA01 and AB-PA01 treatment significantly (p < 0.05) reduced the biofilm biomass of their hosts, regardless of the antibiotic-resistant characteristics of the isolates and the presence of a non-susceptible host. In conclusion, the strong lytic activity, broad host range, and significant biofilm biomass reduction of AB-SA01 and AB-PA01 suggest the considerable potential of phages in treating antibiotic-resistant S. aureus and P. aeruginosa infections alone or as coinfections in DFUs.

Effect of GA3 and calcium on growth, biochemical, and fatty acid composition of linseed under chloride-dominated salinity.

The accumulation of salts in soil is an environmental threat affecting plant growth and crop yield. Linseed or flax is an ancient crop that has multifarious utilities in terms of industrial oil, textile fiber, and products. Salt susceptibility adversely affects linseed production, particularly to meet the growing demand for nutritional and nutraceutical products. In the present study, the ameliorative potential of gibberellic acid (GA3) and calcium (Ca2+) in mitigating the adverse effects of chloride-dominated salinity stress on the growth and physiological and biochemical processes in linseed was determined. Severe salinity treatment (10 dSm-1) resulted in stunted growth of tested linseed genotypes causing a significant reduction in biomass while proline content, phenol, H2O2, lipid peroxidation, and DPPH activity were increased in comparison to control. The exogenous application of 10-6M GA3 and/or 10mg CaCl2 kg-1 was found to mitigate the adverse effects of salinity stress. The mitigation was accomplished through the improvement of growth indicators, increased osmoprotectants such as proline and phenol content, stimulating DPPH activity, and reduction of H2O2 content and lipid peroxidation. The comparative evaluation of different saline treatments imposed individually and in combination with GA3 and Ca2+ revealed that combined GA3 and Ca2+ application exhibited synergistic effects and was most effective in mitigating the negative impacts of salt stress. The present study unravels the ameliorative role of GA3 and Ca2+ (individual or combined) in the physiologic-biochemical adaptive response of linseed plants grown under chloride-dominated salinity and thus aids in a better understanding of the underlying tolerance mechanisms of plants to withstand stress in saline environments.

Enhancing stress resilience in rice (Oryza sativa L.) through profiling early-stage morpho-physiological and molecular responses to multiple abiotic stress tolerance.

Under changing climatic conditions, crop plants are more adversely affected by a combination of various abiotic stresses than by a single abiotic stress. Therefore, it is essential to identify potential donors to multiple abiotic stresses for developing climate-resilient crop varieties. Hence, the present study was undertaken with 41 germplasm accessions comprising native landraces of Tamil Nadu, Prerelease lines and cultivars were screened independently for drought, salinity, and submergence at the seedling stage during Kharif and Rabi 2022-2023. Stress was imposed separately for these three abiotic stresses on 21-day-old seedlings and was maintained for 10 days. The studied genotypes showed a significant reduction in plant biomass (PB), Relative Growth Index (RGI), relative water content (RWC), leaf photosynthesis, chlorophyll fluorescence, and Chlorophyll Concentration Index (CCI) under drought followed by salinity and submergence. Stress-tolerant indices for drought, salinity, and submergence revealed significant variation for plant biomass. Furthermore, a set of 30 SSR markers linked to drought, salinity, and submergence QTLs has been used to characterize 41 rice germplasm accessions. Our analysis suggests a significantly high polymorphism, with 28 polymorphic markers having a 93.40% in 76 loci. The mean values of polymorphic information content (PIC), heterozygosity index (HI), marker index (MI), and resolving power (RP) were 0.369, 0.433, 1.140, and 2.877, respectively. Jaccard clustering grouped all the genotypes into two major and six subclusters. According to STRUCTURE analysis, all genotypes were grouped into two major clusters, which are concurrent with a very broad genetic base (K = 2). Statistically significant marker-trait associations for biomass were observed for five polymorphic markers, viz., RM211, RM212 (drought), RM10694 (salinity), RM219, and RM21 (submergence). Similarly, significant markers for relative shoot length were observed for RM551 (drought), RM10694 (salinity), and ART5 (submergence). Notably, the genotypes Mattaikar, Varigarudan samba, Arupatham samba, and APD19002 were identified as potential donors for multiple abiotic stress tolerance. Thus, identifying the genetic potential of germplasm could be useful for enhancing stress resilience in rice.

Impact of low light intensity on biomass partitioning and genetic diversity in a chickpea mapping population.

With recent climatic changes, the reduced access to solar radiation has become an emerging threat to chickpeas' drought tolerance capacity under rainfed conditions. This study was conducted to assess, and understand the effects of reduced light intensity and quality on plant morphology, root development, and identifying resistant sources from a Sonali/PBA Slasher mapping population. We evaluated 180 genotypes, including recombinant inbred lines (RILs), parents, and commercial checks, using a split-block design with natural and low light treatments. Low light conditions, created by covering one of the two benches inside two growth chambers with a mosquito net, reduced natural light availability by approximately 70%. Light measurements encompassed photosynthetic photon flux density, as well as red, and far-red light readings taken at various stages of the experiment. The data, collected from plumule emergence to anthesis initiation, encompassed various indices relevant to root, shoot, and carbon gain (biomass). Statistical analysis examined variance, treatment effects, heritability, correlations, and principal components (PCs). Results demonstrated significant reductions in root biomass, shoot biomass, root/shoot ratio, and plant total dry biomass under suboptimal light conditions by 52.8%, 28.2%, 36.3%, and 38.4%, respectively. Plants also exhibited delayed progress, taking 9.2% longer to produce their first floral buds, and 19.2% longer to commence anthesis, accompanied by a 33.4% increase in internodal lengths. A significant genotype-by-environment interaction highlighted differing genotypic responses, particularly in traits with high heritability (> 77.0%), such as days to anthesis, days to first floral bud, plant height, and nodes per plant. These traits showed significant associations with drought tolerance indicators, like root, shoot, and plant total dry biomass. Genetic diversity, as depicted in a genotype-by-trait biplot, revealed contributions to PC1 and PC2 coefficients, allowing discrimination of low-light-tolerant RILs, such as 1_52, 1_73, 1_64, 1_245, 1_103, 1_248, and 1_269, with valuable variations in traits of interest. These RILs could be used to breed desirable chickpea cultivars for sustainable production under water-limited conditions. This study concludes that low light stress disrupts the balance between root and shoot morphology, diverting photosynthates to vegetative structures at the expense of root development. Our findings contribute to a better understanding of biomass partitioning under limited-light conditions, and inform breeding strategies for improved drought tolerance in chickpeas.

Simulation of Maize Biomass and Yield in An Giang, Vietnam, under Climate Variabilities

In this study, the SIMPLECrop model was applied to simulate maize biomass and yield in 2 crop seasons, Autumn - Winter 2020 (AW) and Winter - Spring 2020 - 2021 (WS), in Cho Moi district, An Giang province, Vietnam (10°23'47''N, 105°27'41''E). The research aimed to analyze the effects of climate variabilities, particularly increased temperature, on maize growth and yield. The growth period for the Winter - Spring 2020 - 2021 season was 67 days, which was 1 day longer than the AW season (Autumn - Winter 2020). Four cultivar parameters, namely Tsum, HI, I50A, and I50B, were employed for the calibration process to fine-tune the model. Sensitivity analysis using Morris and FAST methods revealed that RUE and Tbase had the highest sensitivity and significant impact on the SIMPLECrop model. These 2 parameters showed strong interactions and played a crucial role in influencing model outcomes. The evaluation of the model’s performance resulted in RRMSE values ranging from 4.8 to 6.3 % and NSE values between 0.86 and 0.93, indicating good agreement between model predictions and observed data. Regarding the impact of temperature increase, a 5 °C temperature rise led to a reduction in stover biomass ranging from 5.2 % (Autumn - Winter 2020) to 19.3 % (Winter - Spring 2020 - 2021) and a decrease in yield by 11.3 % (Autumn - Winter 2020) and 27.0 % (Winter - Spring 2020 - 2021). Simulating an increase in CO2 concentration alone, varying from 50, 100, 150, 200 to 250 ppm, resulted in increased biomass and yield for maize. The most substantial increases were observed at 250 ppm CO2, with approximately 2.5 % higher biomass and 7.7 to 9.1 % greater yield. However, under more severe heat stress (5 °C increase), the positive effects of elevated CO2 were mitigated, resulting in a reduced increase in biomass and yield, approximately 3 - 5 %. These findings highlight the importance of considering temperature and CO2 interactions when assessing crop responses to climate variability. HIGHLIGHTS The SIMPLECrop model was rigorously validated for maize in An Giang Province, Vietnam. Validation metrics, including RRMSE and NSE, demonstrated good-fit model performance, with RRMSE values ranging from 4.8 to 6.3 % and NSE values between 0.86 and 0.93 for open field conditions. Sensitivity analysis using Morris and FAST methods identified that two parameters, RUE (Radiation Use Efficiency) and Tbase (Base Temperature), consistently exhibited the highest sensitivity within the SIMPLECrop model. These parameters played a pivotal role in influencing model outcomes and understanding maize responses to climate variability. The study examined the combined impact of increased temperature and elevated CO2 on maize. A 5 °C temperature rise led to significant stover biomass reductions, varying from 5.2 % (AW season) to a substantial 19.3 % (WS season), along with yield declines of 11.3 % (AW) and a significant 27.0 % (WS). Elevated CO2, ranging from 50 to 250 ppm, had a positive influence on maize biomass and yield. However, under more intense heat stress (5 °C increase), the favorable CO2 effects diminished. This underscores the necessity of considering temperature and CO2 interactions when analyzing crop responses to climate variability. GRAPHICAL ABSTRACT

Phytoplankton Community Dynamics in Ponds with Diverse Biomanipulation Approaches

The rising challenge of eutrophication in aquatic systems globally necessitates an understanding of phytoplankton community dynamics under diverse biomanipulation approaches. This study, conducted from June 2022 to July 2023 in the Yuqiao Reservoir’s ponds in China, explored phytoplankton dynamics across ponds under different biomanipulation strategies. The study included a pond (BL) without fish stocking, a pond (CH) stocked with carnivorous and herbivorous fish, and another pond (CFD) incorporating a mix of carnivorous, filter-feeding, and detritus-feeding fish. Substantial seasonal variations in phytoplankton density and biomass were observed. In the BL pond, phytoplankton density ranged from 0.23 × 107 to 3.21 × 107 ind/L and biomass from 0.71 to 7.10 mg/L, with cyanobacteria predominantly in warmer seasons and a shift to cryptophytes and chrysophytes in winter. The CH pond exhibited a density range from 0.61 × 107 to 8.04 × 107 ind/L and biomass of 1.11 to 7.58 mg/L. Remarkably, the CFD pond demonstrated a significant reduction in both density (0.11 × 107 to 2.36 × 107 ind/L) and biomass (0.27 to 5.95 mg/L), indicating the effective implementation of its biomanipulation strategy. Key environmental factors including total nitrogen, water temperature, pH, chlorophyll-a, and total phosphorus played a significant role in shaping phytoplankton communities. The study highlights the importance of tailored biomanipulation strategies in aquatic ecosystem management, emphasizing long-term monitoring for sustainable management of eutrophication.

Alone as effective as together: AMF and Trichoderma inoculation boost maize performance but differentially shape soil and rhizosphere microbiota

AbstractIntroductionInoculation of plants with beneficial microorganisms may improve plant performance yet suffers from efficacy variability. A solution might be the combined application of different inoculants as consortium. The objective of the present study was to evaluate the effects of single or combined inoculation of Trichoderma harzianum, strain TGFG411, and a consortium of arbuscular mycorrhizal fungi (AMF) on plant growth, and native microbial communities (here bacteria/archaea, fungi and AMF) in root‐associated soil (RAS) and rhizosphere (RH), that is, soil loosely or tightly attached to the roots, respectively.Materials and MethodsA greenhouse experiment was carried out with non‐sterile agricultural soil and the model crop maize, which was single inoculated with either TGFG411 or AMF or received a combined inoculation of TGFG411 + AMF. Control plants received only water. Seven weeks after the second AMF inoculation, the plant growth promotion capacity of the inoculants was measured based on shoot and root parameters. Furthermore, RAS and RH microbiota (fungi including AMF, bacteria and archaea) were assessed via a combination of different cultivation‐dependent, microscopic and DNA‐based methods.ResultsAfter 7 weeks of maize growth, both single and combined inoculation of AMF and TGFG411 enhanced shoot dry weight and led to a significant reduction in root biomass. The TGFG411 strain successfully established in the soil. However, no definite evidence for the establishment of the inoculated AMF was found. Single or combined inoculation of TGFG411 and AMF modified the composition of total bacterial in the RH, whereas modulated total fungal communities in the RAS.ConclusionThe combined inoculation did not result in a significant improvement of plant performance compared with single inoculation likely due to optimal nutrient supply. However, samples receiving the combined inoculation exhibited a distinct modulation of the native RAS/RH microbiota, which may influence the inoculant efficacy under less favourable conditions.

Root-shoot ratio and SOD activity are associated with the sensitivity of common bean seedlings to NaCl salinization

The response of two common bean (Phaseolus vulgaris) varieties with different sensitivities to salinity (Montalbán: sensitive; I-193: moderately sensitive) was studied to determine some phytometric and physiological characteristics that could be associated with their differential sensitivities. Plants were sown in a greenhouse during the seedling stage and irrigated with a nutrient solution to which NaCl of 60 mol m−3 was added, while a control group was maintained in parallel. In Montalban, salinity caused a significant reduction in root biomass while shoot biomass and leaf area decreased with salt stress in both genotypes. The root/shoot ratio slightly increased in I.193 and decreased in Montalban salinized plants. Chlorophyll content increased with salinity in both genotypes. The presence of O2·- (superoxide radicle) in root apex decreased under the saline condition which did not occur in the case of H2O2. Superoxide dismutase (SOD) activity increased in roots and primary leaves under salt stress to a greater extent in I-193 than in Montalban. Four SOD isoenzymes were detected, one MnSOD, one FeSOD, and two Cu/ZnSOD, but their expression varied according to the variety. Catalase (CAT) activity increased only in the roots of stressed Montalban plants. These results suggest that root/shoot ratio and SOD enzyme activity are related to the lower salt sensitivity shown by I-193.

Two promising Bacillus-derived antifungal lipopeptide leads AF4 and AF5 and their combined effect with fluconazole on the in vitro Candida glabrata biofilms.

Introduction: Candida species are endowed with the ability to produce biofilms, which is one of the causes of pathogenicity, as biofilms protect yeasts from antifungal drugs. Candida glabrata (Nakaseomyces glabrata) is one of the most prevalent pathogenic yeasts in humans and a biofilm producer. Methods: The study was aimed at evaluating the combined effects of two highly promising antifungal biomolecules (AF4 and AF5) lipopeptide in nature, chromatographically purified to homogeneity from Bacillus subtilis (B. subtilis) and the standard antifungal fluconazole (at different concentrations) to demonstrate C. glabrata biofilm formation inhibition. Biofilm production and inhibition were evaluated by quantification of the biofilm biomass and metabolic activity using crystal violet (CV) staining and XTT reduction assays, respectively. Microscopic techniques such as confocal scanning laser microscopy (CSLM) and scanning electron microscopy (SEM) were employed to visualize biofilm formation and inhibition. Results and Discussion: Compared to untreated and fluconazole-treated biofilms, an enhanced in vitro anti-biofilm effect of the antifungal lipopeptides AF4/AF5 alone and their combinations with fluconazole was established. The lipopeptides AF4/AF5 alone at 8 and 16μg/mL exhibited significant biomass and metabolic activity reductions. SEM and CSLM images provided evidence that the lipopeptide exposure results in architectural alterations and a significant reduction of C. glabrata biofilms, whereas (2', 7'-dichlorofluorescin diacetate (DCFDA) and propidium iodide (PI) analyses showed reactive oxygen species (ROS) generation along with membrane permeabilization. The estimation of exopolysaccharides (EPS) in AF4/AF5-treated biofilms indicated EPS reduction. The combinations of fluconazole (64/128μg/mL) and AF4/AF5 lipopeptide (16μg/mL) were found to significantly disrupt the mature (24h) biofilms as revealed by CSLM and SEM studies. The CSLM images of biofilms were validated using COMSTAT. The FTIR-analyses indicate the antibiofilm effects of both lipopeptides on 24h biofilms to support CSLM and SEM observations. The combinations of fluconazole (64/128μg/mL) and AF4/AF5 lipopeptide were found to disrupt the mature biofilms; the study also showed that the lipopeptides alone have the potentials to combat C. glabrata biofilms. Taken together, it may be suggested that these lipopeptide leads can be optimized to potentially apply on various surfaces to either reduce or nearly eradicate yeast biofilms.

Traits contributing to salinity tolerance in rice genotypes from the Mekong Delta

AbstractIncreasing sea level rise and subsequent salinization in mega deltas, such as the Vietnamese Mekong Delta (VMD), pose a risk to rice (Oryza sativa L.) production during the dry season. This study investigated the salinity resistance of a selection of common rice genotypes from the VMD along with an international check, IR64. The 20 rice varieties were grown hydroponically for 5 weeks in a greenhouse and then exposed to three levels of NaCl concentration (0 mM, 50 mM and 100 mM) over a period of 2 weeks to determine their susceptibility to salinity. Rice plants were scored and SPAD (leaf greenness) and PRI (photochemical reflectance index) were measured on the youngest fully developed leaf on the main tiller. After harvesting the 7‐week‐old plants, biomass and ion (K+, Cl−, Na+) content were determined by organ across all tillers. Averaged over all varieties, both at 50 mM and 100 mM NaCl, there was a significant reduction in plant biomass, 39% and 52% respectively. However, the effect of the NaCl treatments and the uptake of Cl− and Na+ were significantly different between varieties (p &lt; .0001). Using biomass and ion content as part of a multivariate analysis, varieties were classified according to their susceptibility to salinity and their predominant strategy towards managing ion accumulation. The grouped varieties were further characterized by patterns in Cl− and Na+ partitioning and nondestructive parameters such as SPAD and PRI.

Deciphering the effect of salinity and boron stress on broccoli plants reveals that membranes phytosterols and PIP aquaporins facilitate stress adaptation

Abiotic stresses, such as salinity and boron toxicity/deficiency, are prevalent in arid and semi-arid regions where broccoli is largely cultivated. This study aimed to investigate the physiological response of broccoli leaves to these stresses, focusing on parameters such as growth, relative water content, stomatal conductance, and mineral concentration after 15 days of treatment application. The effects of individual and combined stresses of salinity and boron (deficiency and toxicity) were examined. Additionally, the study explored the molecular aspects of PIP aquaporins in relation to their presence in the plasma membrane and their interaction with the lipid environment. The results showed that the combined stress of salinity and boron deficiency resulted in a significant reduction in plant biomass, suggesting a specific adaptation to this stress combination. Changes in stomatal conductance and mineral nutrient levels indicated that the adaptation mechanisms were associated with water and boron concentration in the leaves. The expression patterns of PIP aquaporins varied among the different stress treatments, either individually or in combination. Furthermore, the presence of aquaporins in the plasma membrane and microsomal fraction highlighted the potential regulatory roles of trafficking along with the membrane composition, particularly the concentration of phytosterols. The results underscore the importance of water transport by aquaporins and their interaction with the sterol composition in the membranes, in facilitating salinity-boron stress adaptation mechanisms.

Quantitative analysis of selenium species in the edible parts of cabbage, carrot, tomato and green pea treated with selenate-enriched irrigation water

Background and aimsSelenium (Se)-biofortified foods are able to compensate for Se deficient diets, but the proportion of different Se species varies among plant species, and the bioavailability of Se species also varies. This study aims to examine the Se species composition of four vegetables.MethodsThe effect of Se-enriched irrigation water on the concentrations of Se species in the edible parts of cabbage, carrots, tomatoes and green peas grown on different soil types was investigated and quantified using HPLC-ICP-MS with either standard addition or isotope dilution.ResultsCabbage leaf and carrot root contained a high proportion (88 and 92%, respectively) of selenate (SeVI), while in tomato fruit and green pea seed selenomethionine (SeMet) was found in the highest proportion (33% and 48%, respectively), but elemental Se was also detected. The elemental Se concentration of peas was significantly higher on sandy soil (2.29 mg kg−1) than on sandy silt (1.38 mg kg−1) or silt soil (1.34 mg kg−1). In 100 g of fresh edible parts, the largest amount of Se species was found in cabbage leaves, but organic Se in the form of SeMet was the most abundant in green peas, being significantly higher than in carrots or tomatoes. Tomatoes contained a nearly three-fold ratio of organic Se to inorganic Se, the latter being mostly comprised of the elemental form, which is unusually high in vegetables. The highest rate of unknown Se species exceeded 66% in the case of peas, while the highest identification rate (> 95%) of Se could be achieved in tomato.ConclusionTomatoes converted the absorbed Se into organic Se in the highest ratio, while green peas had the highest amount of organic Se in fresh biomass, so biotransformation was the most effective for these vegetables without any significant biomass reduction. These vegetables may be adapted to soils with a higher Se content.

Flood Tolerance of Hybrid Napier (Pennisetum purpureum x Pennisetum glaucum) Cultivars

A pot culture study was conducted from February to May 2020 at the Agronomy Farm, Department of Agronomy, College of Agriculture, Vellanikkara, Kerala to study the effects of short-term flooding on the growth, physiology, and yield of four high-yielding cultivars of hybrid napier (Pennisetum purpureum x Pennisetum glaucum) cultivated in Kerala. The experiment followed a 4 x 2 factorial Completely Randomized Design with three replications. The treatments comprised two factors: varieties and flooding treatments. The four hybrid napier varieties used in the study were CO-3 (V1), CO-5 (V2), IGFRI -3 (V3), and Suguna (V4). The flooding treatments included no flooding (F0) as a control and short-term flooding stress treatment (F1) at three different growth stages: 30 days after planting (DAP), 60 DAP and just after the first harvest (75 DAP). Flooding stress was imposed for seven days by inundating water in the pots up to 3-4 cm above the soil level. Flooding at all three stages resulted in a significant reduction in plant height, tiller number, leaf number and above-ground biomass for all varieties. A severe reduction in growth and yield parameters was observed when flooding stress was imposed immediately after the first harvest. Among the varieties, CO-5 had the tallest plants, followed by Suguna, CO-3, and IGFRI-3. When exposed to flooding stress, variety CO-5 was also found to be significantly superior in terms of above-ground biomass production, followed by CO-3. Superoxide dismutase (SOD) activity increased in all varieties due to flooding stress, with a pronounced increase observed in Suguna. Variety CO-5, which exhibited greater plant height and above-ground biomass production, was found to be more tolerant to flooding stress, while variety IGFRI-3, with a dwarf plant stature and the lowest biomass yield, was identified as sensitive to short-term flooding stress.