Pepper (Capsicum annuum L.) is an important agricultural crop because of the nutritional value of the fruit and its economic importance.Various techniques have been practiced to enhance pepper's productivity and n...Pepper (Capsicum annuum L.) is an important agricultural crop because of the nutritional value of the fruit and its economic importance.Various techniques have been practiced to enhance pepper's productivity and nutritional value.Therefore,this study was conducted to determine the impact of different training methods and biostimulant applications on sweet pepper plants'growth,yield,and chemical composition under greenhouse conditions.For the training method,unpruned plants were compared with one stem and two stem plants.Unpruned plants had the fruit number of 33.98,fruit weight of 2.18 kg·plant^(-1),and total marketable yield of 1 090.0 kg·hm^(-2).One stem plant gave the best average fruit weight of 86.63 g,vitamin C content of 13.66 mg·kg^(-1)FW,and TSS content of 7.21%.However,two stem plants had the highest fruit setting of 62.41%,carotenoid content of 0.14 mg·kg^(-1)FW,and fruit chlorophyll content of 3.57 mg·kg^(-1)FW.For biostimulant applications,control plants were compared with the Disper Root (DR) and Disper Vital (DV).DR application significantly increased total sugar,carotenoid,fruit chlorophyll,and TSS contents compared to the control and DV applications.While,applying DV increased fruit setting,plant fruit number,weight,and total marketable yield.In addition,integrating one stem plant with the DR application improved fiber,vitamin C,and TSS contents significantly.Two stem plants,and the DV application improved fruit setting and carotenoid content.Thus,one and two stem training methods integrated with the DR and DV biostimulant applications could be considered for developing agricultural practices to obtain commercial yield and improve the nutrition values of sweet peppers,as unpruned plants without biostimulant applications have a negative impact.展开更多
Tomato is an economically important crop that is susceptible to biotic and abiotic stresses,situations that negatively affect the crop cycle.Biotic stress is caused by phytopathogens such as Fusarium oxysporum f.sp.ly...Tomato is an economically important crop that is susceptible to biotic and abiotic stresses,situations that negatively affect the crop cycle.Biotic stress is caused by phytopathogens such as Fusarium oxysporum f.sp.lycopersici(FOL),responsible for vascular wilt,a disease that causes economic losses of up to 100%in crops of interest.Nanomaterials represent an area of opportunity for pathogen control through stimulations that modify the plant development program,achieving greater adaptation and tolerance to stress.The aim of this study was to evaluate the antimicrobial capacity of the nanoparticles and the concentrations used in tomato plants infected with FOL.To this end,a two-stage experiment was conducted.In Stage 1,the effects of the nanomaterials(Graphene nanoplatelets[GP],Zinc oxide nanoparticles[ZnO NPs],Magnesium oxide nanoparticles[MgO NPs])were evaluated both alone and in combination to determine the most effective method of controlling FOL-induced disease.In Stage 2,the most effective combination of nanomaterials(ZnO+GP)was evaluated at four concentrations ranging from 100 to 400 mg L^(−1).To evaluate the effectiveness of the treatments,we determined the incidence and severity of the disease,agronomic parameters,as well as the following biochemical variables:chlorophylls,β-carotene,vitamin C,phenols,flavonoids,hydrogen peroxide,superoxide anion,and malondialdehyde.The results show various positive effects,highlighting the efficiency of the ZnO+GP at 200mg L^(−1),which reduced the severity by approximately 20%,in addition to increasing agronomic variables and reducing reactive oxygen species.Moreover,the results show that the application of these nanomaterials increases vegetative development and defense against biotic stress.The use of nanomaterials such as zinc oxide,magnesium oxide and graphene can be an effective tool in the control of the severity of Fusarium oxysporum disease.展开更多
Selenium(Se)is a nutrient that is considered beneficial for plants,because its improvement in growth,yield and quality helps plants to mitigate stress.The objective of this research was to evaluate the application of ...Selenium(Se)is a nutrient that is considered beneficial for plants,because its improvement in growth,yield and quality helps plants to mitigate stress.The objective of this research was to evaluate the application of sodium selenite(Na2SeO3),nanoparticles(SeNPs)and microparticles(SeMPs)of Se in cucumber seedlings,via two experiments:one with seed priming and the other with foliar application of Sematerials.The doses used were:0,0.1,0.5,1.0,1.5 and 3.0 mg⋅L^(−1),for each form of Se and for each form of application.Treatment 0 consisted of the application of distilled water,which was used as a control.The results indicated that the SeMPs treatment at 3.0 mg⋅L^(−1)for seed priming had the greatest effect on stem diameter and leaf area.Foliar application of SeMPs at 1.5 mg⋅L^(−1)was the most effective at increasing the leaf area.In terms of fresh and dry biomass(aerial,root and total)for seed priming,all the treatments were superior to the control,and SeMPs at 1.5 and 3.0 mg⋅L^(−1)caused the greatest effects.With foliar application,fresh root biomass improved to a greater extent with the SeMPs treatment at 3.0 mg⋅L^(−1),and dry biomass(aerial,root and total)increased with the SeMPs at 1.0 and 3.0 mg⋅L^(−1).With respect to the photosynthetic pigments,proteins,phenols and minerals,the Se treatments,both for seed priming and foliar application,caused increases and decreases;however,reduced glutathione(GSH)increased with treatments in both forms of application.The Se concentration in the seedlings increased as the dose of Se material increased,and greater accumulation was achieved with foliar application of SeNPs and SeMPs.The results indicate that the use of Se materials is recommended,mainly the use of SeMPs,which improved the variables studied.This opens new opportunities for further studies with SeMPs,as little information is available on their application in agricultural crops.展开更多
Soybean yield contests have been generating useful information regarding the cultivation of this important crop commodity. The aim of this study was to analyze environmental, management, and economic variables associa...Soybean yield contests have been generating useful information regarding the cultivation of this important crop commodity. The aim of this study was to analyze environmental, management, and economic variables associated with soybean yield contest winners in Brazil. Data from eleven summer soybean harvests included grain yield, rainfall, climatic and agronomic efficiency, soil chemical and physical attributes, management strategies, and economic indicators. Two grain yield classes were evaluated: 1) high yield(4967–6839 kg ha^(-1)) and 2) very high yield(6859–8945 kg ha^(-1)). Enhanced soybean yield was due to adequate rainfall that led to high climatic efficiency(77%) and high agronomic efficiency;average values ranged between 78%(high yield class) and 86%(very high yield class). Correction and maintenance of soil chemical and physical quality(surface and subsurface), alternative fertilization and microbial co-inoculation were notable. Winners in the very high yield class reported higher soil K^(+), Ca^(2+), and Mg^(2+) levels, more frequent use of dolomitic limestone, greater soil structural quality, greater use of biostimulants(via foliar spray), and higher net revenue. While high climatic efficiency was fundamental for success, intensive integration of technologies with conservation practices for better soil and crop management are necessary to maximize soybean yield and economic gains.展开更多
Fungal plant diseases are infections caused by pathogenic fungi that affect crops,ornamental plants,and trees.Symptoms of these diseases can include leaf spots,fruit rot,root rot,and generalized growth retardation.Fun...Fungal plant diseases are infections caused by pathogenic fungi that affect crops,ornamental plants,and trees.Symptoms of these diseases can include leaf spots,fruit rot,root rot,and generalized growth retardation.Fungal diseases can result in decreased quality and quantity of crops,which can have a negative economic impact on farmers and producers.Moreover,these diseases can cause environmental damage.Indeed,fungal diseases can directly affect crops by reducing plant growth and yield,as well as altering their quality and nutritional value.Although effective,the use of many chemical products is often harmful to health and the environment,and their use is increasingly restricted due to their high toxicity.To address this issue,it is becoming increasingly essential to replace these chemical products with products that respect the environment and human health,and for sustainable agriculture,such as regenerative agricultural practices.Regenerative agricultural practices such as crop rotation,intercropping,composting,and notill farming techniques can offer sustainable solutions for the prevention and control of plant fungal diseases.These regenratives approaches not only help to control fungal plant disease by strengthening plant disease resistance,but also significantly contribute to the improvement of sustainable agriculture,by restoring soil health,increasing biodiversity and reducing the use of harmful chemicals to the environment and human health in order to keep a long-termecosystem resilience,promote environmental sustainability,and support global food security.Using regenerative agricultural practices can provide a holistic and effective approach to controlling fungal plant diseases while improving the health and productivity of farming systems.展开更多
In semi-arid regions where climatic limitations hinder open-field vegetable production,greenhouse-based lettuce(Lactuca sativa L.)cultivation plays a vital role in ensuring off-season supply.In this study,the potentia...In semi-arid regions where climatic limitations hinder open-field vegetable production,greenhouse-based lettuce(Lactuca sativa L.)cultivation plays a vital role in ensuring off-season supply.In this study,the potential of sustainable input combinations was evaluated to enhance lettuce productivity,quality,and profitability under unheated greenhouse conditions in Southeastern Türkiye.Treatments included farmer practice and a mycorrhizal biofertilizer(ERS,a water-soluble arbuscular mycorrhizal fungus product)applied alone or in combination with organic-based biostimulants(IS and NM).Evaluated parameters were plant height,leaf pigmentation(a^(*),h°),SPAD values,vitamin C,nitrogen and phosphorus content,and gross margin.The ERS2+IS&NM treatment significantly enhanced plant height(32.5 cm),vitamin C content(28.63 mg 100 g^(−1) FW),and gross margin($616.09 da^(−1)),along with improved nutrient uptake and leaf coloration.These findings highlight the synergistic benefits of integrating mycorrhizal inoculants with organic-based biostimulants in greenhouse-grown lettuce systems.The results contribute to the development of eco-friendly,climate-resilient production strategies for protected cultivation in semi-arid environments.展开更多
Salinity stress is amajor constraint on agricultural productivity,particularly in arid and semi-arid regions.This study evaluated the potential of Ascophyllum nodosum extract(ANE)in mitigating salinity-induced stress ...Salinity stress is amajor constraint on agricultural productivity,particularly in arid and semi-arid regions.This study evaluated the potential of Ascophyllum nodosum extract(ANE)in mitigating salinity-induced stress and enhancing the growth and physiological performance of Portulaca oleracea L.under NaCl concentrations of 0,50,70,and 100 mM for 50 days.A two-way ANOVA assessed the effects of NaCl concentration,ANE treatment,and their interaction.The results showed that ANE significantly increased plant height at 50 mMNaCl(p=0.0011)but had no effect at higher salinity levels(p>0.05).Shoot dry weight was significantly influenced by the interaction of NaCl and ANE(p=0.0064),with ANE increasing biomass at 0 mM but decreasing it at 100 mM NaCl.However,ANE did not significantly affect root dry weight(p>0.05).Physiological responses indicated a significant increase in proline content at 50mMNaCl(p=0.0011),supporting improved osmotic adjustment.Total soluble protein was significantly enhanced at all salinity levels except 100 mM NaCl(p<0.01).Regarding ionic regulation,ANE had no significant effect on leaf sap pH(p>0.05)but increased electrical conductivity(EC)at 70 and 100 mM NaCl(p<0.01),suggesting a role in ion homeostasis under high salinity.Photosynthetic pigments responded positively to ANE,with significant increases in chlorophyll“a”(p<0.0001)and carotenoid content(p<0.0001),while chlorophyll“b”remained unchanged(p>0.05).These findings highlight ANE’s potential as a sustainable biostimulant for improving salinity tolerance,particularly at moderate NaCl levels.Future research should focus on molecular mechanisms and long-term field applications to optimize ANE’s role in enhancing soil and crop productivity under salinity stress.展开更多
Biostimulation has been proven to be an available approach for microbially induced calcium carbonate precipitation(MICP).However,biostimulation may not be as effective as bioaugmentation in some unfavorable situations...Biostimulation has been proven to be an available approach for microbially induced calcium carbonate precipitation(MICP).However,biostimulation may not be as effective as bioaugmentation in some unfavorable situations.In this study,the feasibility of biochar-assisted MICP for improving the shear strength of calcareous sand is investigated.The optimization of cementation solution for biostimulated MICP is first determined through a series of unconfined compressive tests.The shear characteristics of biocemented calcareous sand,enhanced by biochar and treated through biostimulation,are then assessed using consolidated undrained(CU)shear triaxial tests.To characterize the shear strength of biocemented sand under low effective normal stress,both Mohr-Coulomb failure envelopes and nonlinear failure envelopes were employed.Meanwhile,the current study also compared and analyzed two distinct stress states:maximum principal stress ratio(σ'_(1)/σ'_(3)max)and Skempton’s pore pressure parameter A=0,to identify an appropriate failure criterion for determination of the shear strength parameters.Furthermore,the microscopic features and post-failure characteristics of biochar-assisted calcareous sand were examined and discussed.The findings indicate that biochar can contribute to an increase in cementation content by serving as additional nucleation sites.The study may provide valuable insights into the potential of biochar-assisted MICP for enhancing the biostimulation approach.展开更多
Conventional agrochemical plant biostimulants have been used to increase crop yield and stress resistance,andthis strategy continues to be integral to today's farming.While effective,the large-scale implantations ...Conventional agrochemical plant biostimulants have been used to increase crop yield and stress resistance,andthis strategy continues to be integral to today's farming.While effective,the large-scale implantations of theseproducts are not without environmental,ecological,and cost concerns and the associated climate-change challenges.To alleviate this long-standing pressure on agriculture,designing and developing more biocompatible andsustainable plant stimulants are among the primary focuses of agricultural management.Over the recent decades,the field has witnessed significant progress in emerging naturally derived or nature-inspired nano-biostimulantswith large-active-surface areas,including bio-compounds,biopolymers,and nanocarbons.However,the extraction/preparation of these products may apply additional costs or require specific equipment.More recently,thefield's attention has shifted to the sustainable application of chemical-additive-free biostimulants towards practicalapplications in nano-agriculture.Herein,we rationally designed and reported the first evidence and elucidationon biostimulant impacts of plant-self-derived nano-extracts from donor Arabidopsis thaliana as a model forinducing mirror biostimulant activities in conspecific host seeds,seedlings,and plants.Moreover,we assessed theeffect of donor plants'age on short,mid-,and long-term biocompatibility,growth,and development/maturationof the recipient plants for up to around 30 days.As a proof-of-concept,we found these autologous bio-extractscould effectively promote seed sprouting,seedling germination,and the development of soil-drenched plantsof the same types.Our transmission-electron microscopy characterization of root/shoot pieces shows the presenceof multiple phyto-compounds,including microtubules/actin filaments,cell vacuoles,Golgi stacks/endoplasmicreticulum,cell wall polysaccharide-based cellulose fibers,and organic amorphous nanoparticles and clusters ofcarbon quantum dots in the structure of these extracts.This personalized plant stimulation may induce furthergrowth/defense-related mechanisms,setting new paradigms toward reducing the agrochemical inputs.展开更多
Biostimulators combined with pesticides can reduce the need for chemical crop protection to yield healthy wheat with high grain quality and nutritional value.The goal of this four-year field study was an assessment of...Biostimulators combined with pesticides can reduce the need for chemical crop protection to yield healthy wheat with high grain quality and nutritional value.The goal of this four-year field study was an assessment of the effects of seven levels of sulfonylurea herbicide,morpholine and triazole fungicides,and humic biostimulator protection on concentrations of 20 amino acids(AAs)and on yield parameters under diverse climatic conditions.Application of pesticides and biostimulators reduced amino acid concentrations.Sulfonylurea applied alone reduced AAs least.Chemical(herbicide+fungicide)protection or its combination with humic biostimulator were the most effective strategies for increasing yield,thousand-kernel weight,spike number,grain surface area,and wet gluten.Reduced dosages of fungicides showed effects on AA content and crop parameter values similar to those of the recommended dosages of fungicides and are in line with the European Commission’s “From Farm to Fork”strategy.Humic biostimulators as agents supporting pesticide protection should be optimized for wheat growth stage to achieve the most desirable wheat parameters and implemented in agricultural practice.展开更多
Multiple biostimulation treatments were applied to enhance the removal of heavy crude oil pollutants in the saline soil of Yellow River Delta.Changes of the soil bacterial community were monitored using the terminal r...Multiple biostimulation treatments were applied to enhance the removal of heavy crude oil pollutants in the saline soil of Yellow River Delta.Changes of the soil bacterial community were monitored using the terminal restriction fragment length polymorphism(T-RFLP)and clone library analyses.The 140-day microcosm experiments showed that low C:N:P ratio,high availability of surfactant and addition of bulking agent significantly enhanced the performance,leading to the highest total petroleum hydrocarbon removal.Meanwhile,the bacterial community was remarkably changed by the multiple biostimulation treatments,with the Deltaproteobacteria,Firmicutes,Actinobacteria,Acidobacteria and Planctomycetes being inhibited and the Alphaand Beta-proteobacteria and some unknown Gammaproteobacteria bacteria being enriched.In addition,different hydrocarbon-degraders came to power in the following turn.At the first stage,the Alcanivorax-related Gammaproteobacteria bacteria dominated in the biostimulated soil and contributed mainly to the biodegradation of easily degradable portion of the heavy crude oil.Then the bacteria belonging to Alphaproteobacteria,followed by bacteria belonging to Candidate division OD1,became the dominant oil-degraders to degrade the remaining recalcitrant constituents of the heavy crude oil.展开更多
1,2-Dichloroethane （DCA）, a potential mutagen and carcinogen, is commonly introduced into the environment through its industrial and agricultural use. In this study, the impact of lead and mercury on DCA degradation...1,2-Dichloroethane （DCA）, a potential mutagen and carcinogen, is commonly introduced into the environment through its industrial and agricultural use. In this study, the impact of lead and mercury on DCA degradation in soil was investigated, owing to the complex co-contamination problem frequently encountered in most sites. 1,2-Dichloroethane was degraded readily in both contaminated loam and clay soils with the degradation rate constants ranging between 0.370-0.536 week-1 and 0.309-0.417 week-1, respectively. The presence of heavy metals have a negative impact on DCA degradation in both soil types, resulting in up to 24.11% reduction in DCA degradation within one week. Both biostimulation and treatment additives increased DCA degradation, with the best degradation observed upon addition of glucose and a combination of diphosphate salt and sodium chloride, leading to about 17.91% and 43.50% increase in DCA degradation, respectively. The results have promising potential for effective remediation of soils co-contaminated with chlorinated organics and heavy metals. However, the best bioremediation strategy will depend on the soil types, microbial population present in the soil matrices, nutrients availability and metal forms.展开更多
The bioremediation of a long-term contaminated soil through biostimulation and surfactant addition was evaluated. The concentrations of 1,1,1-trichloro-2,2-bis（4-chlorophenyl）ethane（DDT） and its metabolites 1,1-di...The bioremediation of a long-term contaminated soil through biostimulation and surfactant addition was evaluated. The concentrations of 1,1,1-trichloro-2,2-bis（4-chlorophenyl）ethane（DDT） and its metabolites 1,1-dichloro-2,2-bis（4-chlorophenyl） ethane（DDD） and1,1-dichloro-2,2-bis（4-chlorophenyl） ethylene（DDE） were monitored during an 8-week remediation process. Physicochemical characterization of the treated soil was performed before and after the bioremediation process. The isolation and identification of predominant microorganisms during the remediation process were also carried out. The efficiency of detoxification was evaluated after each bioremediation protocol. Humidity and p H and the heterotrophic microorganism count were monitored weekly. The DDT concentration was reduced by 79% after 8 weeks via biostimulation with surfactant addition（B ＋ S） and 94.3%via biostimulation alone（B）. Likewise, the concentrations of the metabolites DDE and DDD were reduced to levels below the quantification limits. The microorganisms isolated during bioremediation were identified as Bacillus thuringiensis, Flavobacterium sp., Cuprivadius sp.,Variovorax soli, Phenylobacterium sp. and Lysobacter sp., among others. Analysis with scanning electron microscopy（SEM） allowed visualization of the colonization patterns of soil particles. The toxicity of the soil before and after bioremediation was evaluated using Vibrio fischeri as a bioluminescent sensor. A decrease in the toxic potential of the soil was verified by the increase of the concentration/effect relationship EC50 to 26.9% and 27.2% for B ＋ S and B, respectively, compared to 0.4% obtained for the soil before treatment and 2.5%by natural attenuation after 8 weeks of treatment.展开更多
Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to stressors.The current study was perfor...Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to stressors.The current study was performed to investigate the effectiveness of algae(Chlorella vulgaris Beijerinck)foliar applications[1%,3%,or 5%(v/v)]on mitigation of drought stress in broccoli plants subjected to water deficit at 25%of field capacity.The results showed that the broccoli plants grown under drought stress alone exhibited severe disturbance in growth with considerable reductions in the shoot length,and fresh and dry weights,leaf area,relative water content,leaf water potential,and photosynthetic pigment contents and elevated levels of the lipid peroxidation product malondialdehyde in the leaves.Additionally,the foliar application of microalgae mitigated the detrimental effects of drought,leading to better growth performance(increase of 9%–132%)when compared with the drought-stressed plants that had not received an application of microalgae.Microalgae-mediated beneficial effects were particularly evident in the enhancement of the photosynthetic pigment contents,including chlorophyll-a(6%–60%),chlorophyll-b(19%–55%),and total carotenoids(26%–114%).Exogenous microalgae also contributed to the reduction of membrane damage,as proven by significantly decreased levels of malondialdehyde(10%–39%)in the leaves of the broccoli plants exposed to drought stress.The application of microalgae increased the total flavonoid and phenolic contents,and nutrition uptake.Furthermore,the activities of enzymatic antioxidants like ascorbate peroxidase,catalase,glutathione reductase,and superoxide dismutase increased in response to mediation,resulting in significant alleviation of drought-induced oxidative damage.The most effective application concentration of microalgae was determined as 5%.Overall investigations revealed that the foliar application of microalgae could be recommended as a sustainable strategy to improve the defense system of drought-stressed broccoli plants.展开更多
Bacillus thuringiensis/cereus L2 was added as a biostimulant to enhance the biomass accumulation and carotenoid yield of Rhodobacter sphaeroides using wastewater as the culturing medium. Results showed that biostimula...Bacillus thuringiensis/cereus L2 was added as a biostimulant to enhance the biomass accumulation and carotenoid yield of Rhodobacter sphaeroides using wastewater as the culturing medium. Results showed that biostimulation could significantly enhance the R. sphaeroides biomass production and carotenoid yield. The optimal biostimulant proportion was 40 μL（about 6.4 × 10^5CFU）. Through the use of biostimulation, chemical oxygen demand removal, R. sphaeroides biomass production, carotenoid concentration, and carotenoid yield were improved by 178%, 67%, 214%, and 70%, respectively. Theoretical analysis revealed that there were two possible reasons for such increases. One was that biostimulation enhanced the R. sphaeroides wastewater treatment efficiency. The other was that biostimulation significantly decreased the peroxidase activity in R. sphaeroides. The results showed that the highest peroxidase activity dropped by 87% and the induction ratio of the RSP_3419 gene was 3.1 with the addition of biostimulant. The enhanced carotenoid yield in R. sphaeroides could thus be explained by a decrease in peroxidase activity.展开更多
Bacterial-feeding nematodes can promote the bacterial activity through feeding.Bacterial abundance and their activity affect the degradation of polycyclic aromatic hydrocarbons(PAH) such as phenanthrene.The effects of...Bacterial-feeding nematodes can promote the bacterial activity through feeding.Bacterial abundance and their activity affect the degradation of polycyclic aromatic hydrocarbons(PAH) such as phenanthrene.The effects of bacterial-feeding nematodes,bacteria,and their interactions on the degradation of phenanthrene with or without glucose were studied through a microcosm experiment.The results showed that up to 57.0%of phenanthrene in mineral medium contaminated with phenanthrene was degraded in the control with bacteria alone and bacteria with the presence of nematodes and/or glucose increased the degradation of phenanthrene by 25.6%to 36.6%.Although both nematode and bacteria abundance decreased gradually,catechol 2,3-dioxygenase(C230) activity increased during the incubation period.Compared with bacteria alone,the presence of nematodes significantly increased C230 activity as well as the abundance of bacteria;this effect was more pronounced when glucose was present.The results imply that nematodes might promote the removal of phenanthrene from medium by stimulating bacteria and C230 activities.展开更多
In the era of climate change,abiotic stresses(e.g.,salinity,drought,extreme temperature,flooding,metal/metalloid(s),UV radiation,ozone,etc.)are considered as one of the most complex environmental constraints that rest...In the era of climate change,abiotic stresses(e.g.,salinity,drought,extreme temperature,flooding,metal/metalloid(s),UV radiation,ozone,etc.)are considered as one of the most complex environmental constraints that restricts crop production worldwide.Introduction of stress-tolerant crop cultivars is the most auspicious way of surviving this constraint,and to produce these types of tolerant crops.Several bioengineering mechanisms involved in stress signaling are being adopted in this regard.One example of this kind of manipulation is the osmotic adjustment.The quarternary ammonium compound glycinebetaine(GB),also originally referred to as betaine is a methylated glycine derivative.Among the betaines,GB is the most abundant one in plants,which is mostly produced in response to dehydration caused by different abiotic stresses like drought,salinity,and extreme temperature.Glycinebetaine helps in decreased accumulation and detoxification of ROS,thereby restoring photosynthesis and reducing oxidative stress.It takes part in stabilizing membranes and macromolecules.It is also involved in the stabilization and protection of photosynthetic components,such as ribulose-1,5-bisphosphate carboxylase/oxygenase,photosystem II and quarternary enzyme and protein complex structures under environmental stresses.Glycinebetaine was found to perform in chaperone-induced protein disaggregation.In addition,GB can confer stress tolerance in very low concentrations,and it acts in activating defense responsive genes with stress protection.Recently,field application of GB has also shown protective effects against environmental adversities increasing crop yield and quality.In this review,we will focus on the role of GB in conferring abiotic stress tolerance and the possible ways to engineer GB biosynthesis in plants.展开更多
In this study, biostimulation technology was used for bioremediation of nitrobenzene-contaminated groundwater by adding a mixture of lactose and phosphate, peptone, and beef extract. During the process of biostimulati...In this study, biostimulation technology was used for bioremediation of nitrobenzene-contaminated groundwater by adding a mixture of lactose and phosphate, peptone, and beef extract. During the process of biostimulation, the remediation effectiveness, microbial dehydrogenase activities and microbial densities were investigated; the varieties of microbial community structure and composition were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis（PCR-DGGE） technique and the relative abundances of nitrobenzene-degrading gene（nbzA） were determined by fluorescence quantitative real-time PCR（RT-PCR）. Findings show that the removal rate of nitrobenzene in groundwater could reach about 60% by biostimulation with lactose and phosphate, 70% with peptone and 68% with beef extract. The microbial dehydrogenase activities and microbial densities were all improved obviously via biostimulation. The results of PCR-DGGE show that the microbial diversities were improved, and more than ten kinds of dominant microorganisms were detected after biostimulation. RT-PCR results show that the relative abundances of nbzA gene of microbes in groundwater were increased significantly, which indicated that biostimulation actually enhanced the growth of nitrobenzene-degrading bacteria. Therefore, biostimulation is a cost-effective and feasible bioremediation technique for nitrobenzene-contaminated groundwater.展开更多
The possible impacts on nitrogen-cycle in a p-nitrophenol （PNP） polluted soil and the effectiveness of wastewater sludge amendments in restoring nitrification potential and urease activity were evaluated by an incub...The possible impacts on nitrogen-cycle in a p-nitrophenol （PNP） polluted soil and the effectiveness of wastewater sludge amendments in restoring nitrification potential and urease activity were evaluated by an incubation study. The results indicated that PNP at 250 mg/kg soil inhibited urease activity, nitrification potential, arginine ammonification rate and heterotrophic bacteria counts to some extents. After exposure to PNP, the nitrification potential of the tested soil was dramatically reduced to zero over a period of 30 days. Based on the findings, nitrification potential was postulated as a simple biochemical indicator for PNP pollution in soils. Nitrogen-cycling processes in soils responded positively to the applications of wastewater sludges. A sludge application rate of 200 tons/ha was sufficient for successful biostimulation of these nitrogen processes. The microbial activities in sludge-amended, heavy PNP-polluted soils seemed to recover after 30–45 days, indicating the effectiveness of sludge as a useful soil amendment.展开更多
Recently,botanical extracts are gaining popularity as biostimulants in vegetable production.In present study,the effect of aqueous garlic bulb extract(AGE)was studied on the growth and physiology of eggplant grown in ...Recently,botanical extracts are gaining popularity as biostimulants in vegetable production.In present study,the effect of aqueous garlic bulb extract(AGE)was studied on the growth and physiology of eggplant grown in plastic tunnel.AGE was foliage sprayed with various frequencies,i.e.,0,S1(once),S2(twice)and S3(three times)at two independent growth stages,pre-and post-transplant.The results showed that the treated plants exhibited stimulatory responses in growth and physiology in accord with the repetition of AGE spray and growth stages of the plants,respectively.A single foliage sprayed pre-transplant resulted in improved growth,i.e.,plant morphology and biomass,and enhanced antioxidants enzymes(superoxide dismutase,SOD;peroxidase,POD),photosynthesis and chlorophyll abundance observed at vegetative,first flowering and fruit setting stages,respectively.However,thrice application inhibited the plant growth and development and resulted in lipid peroxidation,i.e.,increased malondialdehyde(MDA)content.In addition,the post-transplant application also showed growth stimulation and interestingly,an overall positive influence was observed with respect to the AGE application and no significant increase in the MDA content indicated the post-transplant seedlings responded well.Our findings demonstrate that AGE can act as a biostimulant to enhance the eggplant growth in plastic tunnel production.展开更多
文摘Pepper (Capsicum annuum L.) is an important agricultural crop because of the nutritional value of the fruit and its economic importance.Various techniques have been practiced to enhance pepper's productivity and nutritional value.Therefore,this study was conducted to determine the impact of different training methods and biostimulant applications on sweet pepper plants'growth,yield,and chemical composition under greenhouse conditions.For the training method,unpruned plants were compared with one stem and two stem plants.Unpruned plants had the fruit number of 33.98,fruit weight of 2.18 kg·plant^(-1),and total marketable yield of 1 090.0 kg·hm^(-2).One stem plant gave the best average fruit weight of 86.63 g,vitamin C content of 13.66 mg·kg^(-1)FW,and TSS content of 7.21%.However,two stem plants had the highest fruit setting of 62.41%,carotenoid content of 0.14 mg·kg^(-1)FW,and fruit chlorophyll content of 3.57 mg·kg^(-1)FW.For biostimulant applications,control plants were compared with the Disper Root (DR) and Disper Vital (DV).DR application significantly increased total sugar,carotenoid,fruit chlorophyll,and TSS contents compared to the control and DV applications.While,applying DV increased fruit setting,plant fruit number,weight,and total marketable yield.In addition,integrating one stem plant with the DR application improved fiber,vitamin C,and TSS contents significantly.Two stem plants,and the DV application improved fruit setting and carotenoid content.Thus,one and two stem training methods integrated with the DR and DV biostimulant applications could be considered for developing agricultural practices to obtain commercial yield and improve the nutrition values of sweet peppers,as unpruned plants without biostimulant applications have a negative impact.
文摘Tomato is an economically important crop that is susceptible to biotic and abiotic stresses,situations that negatively affect the crop cycle.Biotic stress is caused by phytopathogens such as Fusarium oxysporum f.sp.lycopersici(FOL),responsible for vascular wilt,a disease that causes economic losses of up to 100%in crops of interest.Nanomaterials represent an area of opportunity for pathogen control through stimulations that modify the plant development program,achieving greater adaptation and tolerance to stress.The aim of this study was to evaluate the antimicrobial capacity of the nanoparticles and the concentrations used in tomato plants infected with FOL.To this end,a two-stage experiment was conducted.In Stage 1,the effects of the nanomaterials(Graphene nanoplatelets[GP],Zinc oxide nanoparticles[ZnO NPs],Magnesium oxide nanoparticles[MgO NPs])were evaluated both alone and in combination to determine the most effective method of controlling FOL-induced disease.In Stage 2,the most effective combination of nanomaterials(ZnO+GP)was evaluated at four concentrations ranging from 100 to 400 mg L^(−1).To evaluate the effectiveness of the treatments,we determined the incidence and severity of the disease,agronomic parameters,as well as the following biochemical variables:chlorophylls,β-carotene,vitamin C,phenols,flavonoids,hydrogen peroxide,superoxide anion,and malondialdehyde.The results show various positive effects,highlighting the efficiency of the ZnO+GP at 200mg L^(−1),which reduced the severity by approximately 20%,in addition to increasing agronomic variables and reducing reactive oxygen species.Moreover,the results show that the application of these nanomaterials increases vegetative development and defense against biotic stress.The use of nanomaterials such as zinc oxide,magnesium oxide and graphene can be an effective tool in the control of the severity of Fusarium oxysporum disease.
文摘Selenium(Se)is a nutrient that is considered beneficial for plants,because its improvement in growth,yield and quality helps plants to mitigate stress.The objective of this research was to evaluate the application of sodium selenite(Na2SeO3),nanoparticles(SeNPs)and microparticles(SeMPs)of Se in cucumber seedlings,via two experiments:one with seed priming and the other with foliar application of Sematerials.The doses used were:0,0.1,0.5,1.0,1.5 and 3.0 mg⋅L^(−1),for each form of Se and for each form of application.Treatment 0 consisted of the application of distilled water,which was used as a control.The results indicated that the SeMPs treatment at 3.0 mg⋅L^(−1)for seed priming had the greatest effect on stem diameter and leaf area.Foliar application of SeMPs at 1.5 mg⋅L^(−1)was the most effective at increasing the leaf area.In terms of fresh and dry biomass(aerial,root and total)for seed priming,all the treatments were superior to the control,and SeMPs at 1.5 and 3.0 mg⋅L^(−1)caused the greatest effects.With foliar application,fresh root biomass improved to a greater extent with the SeMPs treatment at 3.0 mg⋅L^(−1),and dry biomass(aerial,root and total)increased with the SeMPs at 1.0 and 3.0 mg⋅L^(−1).With respect to the photosynthetic pigments,proteins,phenols and minerals,the Se treatments,both for seed priming and foliar application,caused increases and decreases;however,reduced glutathione(GSH)increased with treatments in both forms of application.The Se concentration in the seedlings increased as the dose of Se material increased,and greater accumulation was achieved with foliar application of SeNPs and SeMPs.The results indicate that the use of Se materials is recommended,mainly the use of SeMPs,which improved the variables studied.This opens new opportunities for further studies with SeMPs,as little information is available on their application in agricultural crops.
文摘Soybean yield contests have been generating useful information regarding the cultivation of this important crop commodity. The aim of this study was to analyze environmental, management, and economic variables associated with soybean yield contest winners in Brazil. Data from eleven summer soybean harvests included grain yield, rainfall, climatic and agronomic efficiency, soil chemical and physical attributes, management strategies, and economic indicators. Two grain yield classes were evaluated: 1) high yield(4967–6839 kg ha^(-1)) and 2) very high yield(6859–8945 kg ha^(-1)). Enhanced soybean yield was due to adequate rainfall that led to high climatic efficiency(77%) and high agronomic efficiency;average values ranged between 78%(high yield class) and 86%(very high yield class). Correction and maintenance of soil chemical and physical quality(surface and subsurface), alternative fertilization and microbial co-inoculation were notable. Winners in the very high yield class reported higher soil K^(+), Ca^(2+), and Mg^(2+) levels, more frequent use of dolomitic limestone, greater soil structural quality, greater use of biostimulants(via foliar spray), and higher net revenue. While high climatic efficiency was fundamental for success, intensive integration of technologies with conservation practices for better soil and crop management are necessary to maximize soybean yield and economic gains.
基金provided by SIRAM project within the framework of PRIMA,a program supported by H2020,the European Program for Research and Innovation and the Tunisian Ministry of Higher Education and Scientific Research(MERS).
文摘Fungal plant diseases are infections caused by pathogenic fungi that affect crops,ornamental plants,and trees.Symptoms of these diseases can include leaf spots,fruit rot,root rot,and generalized growth retardation.Fungal diseases can result in decreased quality and quantity of crops,which can have a negative economic impact on farmers and producers.Moreover,these diseases can cause environmental damage.Indeed,fungal diseases can directly affect crops by reducing plant growth and yield,as well as altering their quality and nutritional value.Although effective,the use of many chemical products is often harmful to health and the environment,and their use is increasingly restricted due to their high toxicity.To address this issue,it is becoming increasingly essential to replace these chemical products with products that respect the environment and human health,and for sustainable agriculture,such as regenerative agricultural practices.Regenerative agricultural practices such as crop rotation,intercropping,composting,and notill farming techniques can offer sustainable solutions for the prevention and control of plant fungal diseases.These regenratives approaches not only help to control fungal plant disease by strengthening plant disease resistance,but also significantly contribute to the improvement of sustainable agriculture,by restoring soil health,increasing biodiversity and reducing the use of harmful chemicals to the environment and human health in order to keep a long-termecosystem resilience,promote environmental sustainability,and support global food security.Using regenerative agricultural practices can provide a holistic and effective approach to controlling fungal plant diseases while improving the health and productivity of farming systems.
文摘In semi-arid regions where climatic limitations hinder open-field vegetable production,greenhouse-based lettuce(Lactuca sativa L.)cultivation plays a vital role in ensuring off-season supply.In this study,the potential of sustainable input combinations was evaluated to enhance lettuce productivity,quality,and profitability under unheated greenhouse conditions in Southeastern Türkiye.Treatments included farmer practice and a mycorrhizal biofertilizer(ERS,a water-soluble arbuscular mycorrhizal fungus product)applied alone or in combination with organic-based biostimulants(IS and NM).Evaluated parameters were plant height,leaf pigmentation(a^(*),h°),SPAD values,vitamin C,nitrogen and phosphorus content,and gross margin.The ERS2+IS&NM treatment significantly enhanced plant height(32.5 cm),vitamin C content(28.63 mg 100 g^(−1) FW),and gross margin($616.09 da^(−1)),along with improved nutrient uptake and leaf coloration.These findings highlight the synergistic benefits of integrating mycorrhizal inoculants with organic-based biostimulants in greenhouse-grown lettuce systems.The results contribute to the development of eco-friendly,climate-resilient production strategies for protected cultivation in semi-arid environments.
文摘Salinity stress is amajor constraint on agricultural productivity,particularly in arid and semi-arid regions.This study evaluated the potential of Ascophyllum nodosum extract(ANE)in mitigating salinity-induced stress and enhancing the growth and physiological performance of Portulaca oleracea L.under NaCl concentrations of 0,50,70,and 100 mM for 50 days.A two-way ANOVA assessed the effects of NaCl concentration,ANE treatment,and their interaction.The results showed that ANE significantly increased plant height at 50 mMNaCl(p=0.0011)but had no effect at higher salinity levels(p>0.05).Shoot dry weight was significantly influenced by the interaction of NaCl and ANE(p=0.0064),with ANE increasing biomass at 0 mM but decreasing it at 100 mM NaCl.However,ANE did not significantly affect root dry weight(p>0.05).Physiological responses indicated a significant increase in proline content at 50mMNaCl(p=0.0011),supporting improved osmotic adjustment.Total soluble protein was significantly enhanced at all salinity levels except 100 mM NaCl(p<0.01).Regarding ionic regulation,ANE had no significant effect on leaf sap pH(p>0.05)but increased electrical conductivity(EC)at 70 and 100 mM NaCl(p<0.01),suggesting a role in ion homeostasis under high salinity.Photosynthetic pigments responded positively to ANE,with significant increases in chlorophyll“a”(p<0.0001)and carotenoid content(p<0.0001),while chlorophyll“b”remained unchanged(p>0.05).These findings highlight ANE’s potential as a sustainable biostimulant for improving salinity tolerance,particularly at moderate NaCl levels.Future research should focus on molecular mechanisms and long-term field applications to optimize ANE’s role in enhancing soil and crop productivity under salinity stress.
基金financially supported by the Natural Science Foundation of China(Grant Nos.42377166 and 42007246)Key R&D Program Social Development Project of Jiangsu Province(Grant No.BE2023800)the National Key R&D Program of China(Grant No.2023YFC3709600).
文摘Biostimulation has been proven to be an available approach for microbially induced calcium carbonate precipitation(MICP).However,biostimulation may not be as effective as bioaugmentation in some unfavorable situations.In this study,the feasibility of biochar-assisted MICP for improving the shear strength of calcareous sand is investigated.The optimization of cementation solution for biostimulated MICP is first determined through a series of unconfined compressive tests.The shear characteristics of biocemented calcareous sand,enhanced by biochar and treated through biostimulation,are then assessed using consolidated undrained(CU)shear triaxial tests.To characterize the shear strength of biocemented sand under low effective normal stress,both Mohr-Coulomb failure envelopes and nonlinear failure envelopes were employed.Meanwhile,the current study also compared and analyzed two distinct stress states:maximum principal stress ratio(σ'_(1)/σ'_(3)max)and Skempton’s pore pressure parameter A=0,to identify an appropriate failure criterion for determination of the shear strength parameters.Furthermore,the microscopic features and post-failure characteristics of biochar-assisted calcareous sand were examined and discussed.The findings indicate that biochar can contribute to an increase in cementation content by serving as additional nucleation sites.The study may provide valuable insights into the potential of biochar-assisted MICP for enhancing the biostimulation approach.
基金Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)grant number 525793193Prof.Stefan Eimer and Ms.Marion Basoglu at Goethe University for their assistance in TEM characterization+1 种基金Mr.Holger Schranz for his help in plant cultivation and maintenanceProf.Bruno M.Moerschbacher from the Institute of Plant Biology and Biotechnology at the Münster University。
文摘Conventional agrochemical plant biostimulants have been used to increase crop yield and stress resistance,andthis strategy continues to be integral to today's farming.While effective,the large-scale implantations of theseproducts are not without environmental,ecological,and cost concerns and the associated climate-change challenges.To alleviate this long-standing pressure on agriculture,designing and developing more biocompatible andsustainable plant stimulants are among the primary focuses of agricultural management.Over the recent decades,the field has witnessed significant progress in emerging naturally derived or nature-inspired nano-biostimulantswith large-active-surface areas,including bio-compounds,biopolymers,and nanocarbons.However,the extraction/preparation of these products may apply additional costs or require specific equipment.More recently,thefield's attention has shifted to the sustainable application of chemical-additive-free biostimulants towards practicalapplications in nano-agriculture.Herein,we rationally designed and reported the first evidence and elucidationon biostimulant impacts of plant-self-derived nano-extracts from donor Arabidopsis thaliana as a model forinducing mirror biostimulant activities in conspecific host seeds,seedlings,and plants.Moreover,we assessed theeffect of donor plants'age on short,mid-,and long-term biocompatibility,growth,and development/maturationof the recipient plants for up to around 30 days.As a proof-of-concept,we found these autologous bio-extractscould effectively promote seed sprouting,seedling germination,and the development of soil-drenched plantsof the same types.Our transmission-electron microscopy characterization of root/shoot pieces shows the presenceof multiple phyto-compounds,including microtubules/actin filaments,cell vacuoles,Golgi stacks/endoplasmicreticulum,cell wall polysaccharide-based cellulose fibers,and organic amorphous nanoparticles and clusters ofcarbon quantum dots in the structure of these extracts.This personalized plant stimulation may induce furthergrowth/defense-related mechanisms,setting new paradigms toward reducing the agrochemical inputs.
基金funded by the Ministry of Education and Science in Poland in terms of designated subsidy among statutory activities(SIB-01,SIB-03).
文摘Biostimulators combined with pesticides can reduce the need for chemical crop protection to yield healthy wheat with high grain quality and nutritional value.The goal of this four-year field study was an assessment of the effects of seven levels of sulfonylurea herbicide,morpholine and triazole fungicides,and humic biostimulator protection on concentrations of 20 amino acids(AAs)and on yield parameters under diverse climatic conditions.Application of pesticides and biostimulators reduced amino acid concentrations.Sulfonylurea applied alone reduced AAs least.Chemical(herbicide+fungicide)protection or its combination with humic biostimulator were the most effective strategies for increasing yield,thousand-kernel weight,spike number,grain surface area,and wet gluten.Reduced dosages of fungicides showed effects on AA content and crop parameter values similar to those of the recommended dosages of fungicides and are in line with the European Commission’s “From Farm to Fork”strategy.Humic biostimulators as agents supporting pesticide protection should be optimized for wheat growth stage to achieve the most desirable wheat parameters and implemented in agricultural practice.
基金supported by the International Cooperation Project of National Natural Science Foundation of China(No.40821140541)the National High Technology Research and Development Program(863)of China(No.2009AA063501)
文摘Multiple biostimulation treatments were applied to enhance the removal of heavy crude oil pollutants in the saline soil of Yellow River Delta.Changes of the soil bacterial community were monitored using the terminal restriction fragment length polymorphism(T-RFLP)and clone library analyses.The 140-day microcosm experiments showed that low C:N:P ratio,high availability of surfactant and addition of bulking agent significantly enhanced the performance,leading to the highest total petroleum hydrocarbon removal.Meanwhile,the bacterial community was remarkably changed by the multiple biostimulation treatments,with the Deltaproteobacteria,Firmicutes,Actinobacteria,Acidobacteria and Planctomycetes being inhibited and the Alphaand Beta-proteobacteria and some unknown Gammaproteobacteria bacteria being enriched.In addition,different hydrocarbon-degraders came to power in the following turn.At the first stage,the Alcanivorax-related Gammaproteobacteria bacteria dominated in the biostimulated soil and contributed mainly to the biodegradation of easily degradable portion of the heavy crude oil.Then the bacteria belonging to Alphaproteobacteria,followed by bacteria belonging to Candidate division OD1,became the dominant oil-degraders to degrade the remaining recalcitrant constituents of the heavy crude oil.
基金supported by the Competitive Research Grant of the University of KwaZulu-Natal, Durbanthe National Research Foundation of South Africa.
文摘1,2-Dichloroethane （DCA）, a potential mutagen and carcinogen, is commonly introduced into the environment through its industrial and agricultural use. In this study, the impact of lead and mercury on DCA degradation in soil was investigated, owing to the complex co-contamination problem frequently encountered in most sites. 1,2-Dichloroethane was degraded readily in both contaminated loam and clay soils with the degradation rate constants ranging between 0.370-0.536 week-1 and 0.309-0.417 week-1, respectively. The presence of heavy metals have a negative impact on DCA degradation in both soil types, resulting in up to 24.11% reduction in DCA degradation within one week. Both biostimulation and treatment additives increased DCA degradation, with the best degradation observed upon addition of glucose and a combination of diphosphate salt and sodium chloride, leading to about 17.91% and 43.50% increase in DCA degradation, respectively. The results have promising potential for effective remediation of soils co-contaminated with chlorinated organics and heavy metals. However, the best bioremediation strategy will depend on the soil types, microbial population present in the soil matrices, nutrients availability and metal forms.
基金the GDCON group and the 2013–2014 sustainability grant of the Pro-Vice Chancellor for Research of the University of Antioquia for funding the project
文摘The bioremediation of a long-term contaminated soil through biostimulation and surfactant addition was evaluated. The concentrations of 1,1,1-trichloro-2,2-bis（4-chlorophenyl）ethane（DDT） and its metabolites 1,1-dichloro-2,2-bis（4-chlorophenyl） ethane（DDD） and1,1-dichloro-2,2-bis（4-chlorophenyl） ethylene（DDE） were monitored during an 8-week remediation process. Physicochemical characterization of the treated soil was performed before and after the bioremediation process. The isolation and identification of predominant microorganisms during the remediation process were also carried out. The efficiency of detoxification was evaluated after each bioremediation protocol. Humidity and p H and the heterotrophic microorganism count were monitored weekly. The DDT concentration was reduced by 79% after 8 weeks via biostimulation with surfactant addition（B ＋ S） and 94.3%via biostimulation alone（B）. Likewise, the concentrations of the metabolites DDE and DDD were reduced to levels below the quantification limits. The microorganisms isolated during bioremediation were identified as Bacillus thuringiensis, Flavobacterium sp., Cuprivadius sp.,Variovorax soli, Phenylobacterium sp. and Lysobacter sp., among others. Analysis with scanning electron microscopy（SEM） allowed visualization of the colonization patterns of soil particles. The toxicity of the soil before and after bioremediation was evaluated using Vibrio fischeri as a bioluminescent sensor. A decrease in the toxic potential of the soil was verified by the increase of the concentration/effect relationship EC50 to 26.9% and 27.2% for B ＋ S and B, respectively, compared to 0.4% obtained for the soil before treatment and 2.5%by natural attenuation after 8 weeks of treatment.
文摘Microalgae,such as Chlorella vulgaris Beijerinck(green algae),are beneficial microscopic organisms that may help plants to improve nutrient uptake,growth,and abiotic tolerance to stressors.The current study was performed to investigate the effectiveness of algae(Chlorella vulgaris Beijerinck)foliar applications[1%,3%,or 5%(v/v)]on mitigation of drought stress in broccoli plants subjected to water deficit at 25%of field capacity.The results showed that the broccoli plants grown under drought stress alone exhibited severe disturbance in growth with considerable reductions in the shoot length,and fresh and dry weights,leaf area,relative water content,leaf water potential,and photosynthetic pigment contents and elevated levels of the lipid peroxidation product malondialdehyde in the leaves.Additionally,the foliar application of microalgae mitigated the detrimental effects of drought,leading to better growth performance(increase of 9%–132%)when compared with the drought-stressed plants that had not received an application of microalgae.Microalgae-mediated beneficial effects were particularly evident in the enhancement of the photosynthetic pigment contents,including chlorophyll-a(6%–60%),chlorophyll-b(19%–55%),and total carotenoids(26%–114%).Exogenous microalgae also contributed to the reduction of membrane damage,as proven by significantly decreased levels of malondialdehyde(10%–39%)in the leaves of the broccoli plants exposed to drought stress.The application of microalgae increased the total flavonoid and phenolic contents,and nutrition uptake.Furthermore,the activities of enzymatic antioxidants like ascorbate peroxidase,catalase,glutathione reductase,and superoxide dismutase increased in response to mediation,resulting in significant alleviation of drought-induced oxidative damage.The most effective application concentration of microalgae was determined as 5%.Overall investigations revealed that the foliar application of microalgae could be recommended as a sustainable strategy to improve the defense system of drought-stressed broccoli plants.
基金supported by the National Natural Science Foundation of China (No. 51278489)
文摘Bacillus thuringiensis/cereus L2 was added as a biostimulant to enhance the biomass accumulation and carotenoid yield of Rhodobacter sphaeroides using wastewater as the culturing medium. Results showed that biostimulation could significantly enhance the R. sphaeroides biomass production and carotenoid yield. The optimal biostimulant proportion was 40 μL（about 6.4 × 10^5CFU）. Through the use of biostimulation, chemical oxygen demand removal, R. sphaeroides biomass production, carotenoid concentration, and carotenoid yield were improved by 178%, 67%, 214%, and 70%, respectively. Theoretical analysis revealed that there were two possible reasons for such increases. One was that biostimulation enhanced the R. sphaeroides wastewater treatment efficiency. The other was that biostimulation significantly decreased the peroxidase activity in R. sphaeroides. The results showed that the highest peroxidase activity dropped by 87% and the induction ratio of the RSP_3419 gene was 3.1 with the addition of biostimulant. The enhanced carotenoid yield in R. sphaeroides could thus be explained by a decrease in peroxidase activity.
基金supported by the Shandong Academy of Agricultural Sciences Youth Fund,China(No.2014QNM49)the National Key Technology R&D Program during the 12th Five-Year Plan Period (No.2012BAD15B02)+1 种基金the Program of Taishan Scholars for Overseas Experts,Chinathe Key Project of Science and Technology Innovation of Shandong Academy of Agricultural Sciences,China(No.2014CXZ01)
文摘Bacterial-feeding nematodes can promote the bacterial activity through feeding.Bacterial abundance and their activity affect the degradation of polycyclic aromatic hydrocarbons(PAH) such as phenanthrene.The effects of bacterial-feeding nematodes,bacteria,and their interactions on the degradation of phenanthrene with or without glucose were studied through a microcosm experiment.The results showed that up to 57.0%of phenanthrene in mineral medium contaminated with phenanthrene was degraded in the control with bacteria alone and bacteria with the presence of nematodes and/or glucose increased the degradation of phenanthrene by 25.6%to 36.6%.Although both nematode and bacteria abundance decreased gradually,catechol 2,3-dioxygenase(C230) activity increased during the incubation period.Compared with bacteria alone,the presence of nematodes significantly increased C230 activity as well as the abundance of bacteria;this effect was more pronounced when glucose was present.The results imply that nematodes might promote the removal of phenanthrene from medium by stimulating bacteria and C230 activities.
基金Financial assistance from Council of Scientific and Industrial Research(CSIR),Government of India,through the research grant[38(1387)/14/EMR-II]Science and Engineering Research Board,Government of India through the grant[EMR/2016/004799]+1 种基金Department of Higher Education,Science and Technology and Biotechnology,Government of West Bengal,through the grant[264(Sanc.)/ST/P/S&T/1G-80/2017]to Dr.Aryadeep Roychoudhury is gratefully acknowledgedThe authors are thankful to the University Grants Commission(UGC),Government of India,for providing Junior Research Fellowship to Aditya Banerjee.
文摘In the era of climate change,abiotic stresses(e.g.,salinity,drought,extreme temperature,flooding,metal/metalloid(s),UV radiation,ozone,etc.)are considered as one of the most complex environmental constraints that restricts crop production worldwide.Introduction of stress-tolerant crop cultivars is the most auspicious way of surviving this constraint,and to produce these types of tolerant crops.Several bioengineering mechanisms involved in stress signaling are being adopted in this regard.One example of this kind of manipulation is the osmotic adjustment.The quarternary ammonium compound glycinebetaine(GB),also originally referred to as betaine is a methylated glycine derivative.Among the betaines,GB is the most abundant one in plants,which is mostly produced in response to dehydration caused by different abiotic stresses like drought,salinity,and extreme temperature.Glycinebetaine helps in decreased accumulation and detoxification of ROS,thereby restoring photosynthesis and reducing oxidative stress.It takes part in stabilizing membranes and macromolecules.It is also involved in the stabilization and protection of photosynthetic components,such as ribulose-1,5-bisphosphate carboxylase/oxygenase,photosystem II and quarternary enzyme and protein complex structures under environmental stresses.Glycinebetaine was found to perform in chaperone-induced protein disaggregation.In addition,GB can confer stress tolerance in very low concentrations,and it acts in activating defense responsive genes with stress protection.Recently,field application of GB has also shown protective effects against environmental adversities increasing crop yield and quality.In this review,we will focus on the role of GB in conferring abiotic stress tolerance and the possible ways to engineer GB biosynthesis in plants.
基金Supported by the National Natural Science Foundation of China(No.41072170)the National High Technology Research and Development Program of China(No. 2007AA06A410)the Graduate Innovation Fund of Jilin University, China(No.20111037)
文摘In this study, biostimulation technology was used for bioremediation of nitrobenzene-contaminated groundwater by adding a mixture of lactose and phosphate, peptone, and beef extract. During the process of biostimulation, the remediation effectiveness, microbial dehydrogenase activities and microbial densities were investigated; the varieties of microbial community structure and composition were analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis（PCR-DGGE） technique and the relative abundances of nitrobenzene-degrading gene（nbzA） were determined by fluorescence quantitative real-time PCR（RT-PCR）. Findings show that the removal rate of nitrobenzene in groundwater could reach about 60% by biostimulation with lactose and phosphate, 70% with peptone and 68% with beef extract. The microbial dehydrogenase activities and microbial densities were all improved obviously via biostimulation. The results of PCR-DGGE show that the microbial diversities were improved, and more than ten kinds of dominant microorganisms were detected after biostimulation. RT-PCR results show that the relative abundances of nbzA gene of microbes in groundwater were increased significantly, which indicated that biostimulation actually enhanced the growth of nitrobenzene-degrading bacteria. Therefore, biostimulation is a cost-effective and feasible bioremediation technique for nitrobenzene-contaminated groundwater.
文摘The possible impacts on nitrogen-cycle in a p-nitrophenol （PNP） polluted soil and the effectiveness of wastewater sludge amendments in restoring nitrification potential and urease activity were evaluated by an incubation study. The results indicated that PNP at 250 mg/kg soil inhibited urease activity, nitrification potential, arginine ammonification rate and heterotrophic bacteria counts to some extents. After exposure to PNP, the nitrification potential of the tested soil was dramatically reduced to zero over a period of 30 days. Based on the findings, nitrification potential was postulated as a simple biochemical indicator for PNP pollution in soils. Nitrogen-cycling processes in soils responded positively to the applications of wastewater sludges. A sludge application rate of 200 tons/ha was sufficient for successful biostimulation of these nitrogen processes. The microbial activities in sludge-amended, heavy PNP-polluted soils seemed to recover after 30–45 days, indicating the effectiveness of sludge as a useful soil amendment.
基金funded by the Shaanxi Provincial Science and Technology Innovation Project of China(2016KTCL02-01)
文摘Recently,botanical extracts are gaining popularity as biostimulants in vegetable production.In present study,the effect of aqueous garlic bulb extract(AGE)was studied on the growth and physiology of eggplant grown in plastic tunnel.AGE was foliage sprayed with various frequencies,i.e.,0,S1(once),S2(twice)and S3(three times)at two independent growth stages,pre-and post-transplant.The results showed that the treated plants exhibited stimulatory responses in growth and physiology in accord with the repetition of AGE spray and growth stages of the plants,respectively.A single foliage sprayed pre-transplant resulted in improved growth,i.e.,plant morphology and biomass,and enhanced antioxidants enzymes(superoxide dismutase,SOD;peroxidase,POD),photosynthesis and chlorophyll abundance observed at vegetative,first flowering and fruit setting stages,respectively.However,thrice application inhibited the plant growth and development and resulted in lipid peroxidation,i.e.,increased malondialdehyde(MDA)content.In addition,the post-transplant application also showed growth stimulation and interestingly,an overall positive influence was observed with respect to the AGE application and no significant increase in the MDA content indicated the post-transplant seedlings responded well.Our findings demonstrate that AGE can act as a biostimulant to enhance the eggplant growth in plastic tunnel production.
