[Objective] The study aimed to investigate the growth-promoting activities of endophytic bacteria from tomato plants.[Method]The endophytic bacteria isolated from different tissues of tomato plants were analyzed for t...[Objective] The study aimed to investigate the growth-promoting activities of endophytic bacteria from tomato plants.[Method]The endophytic bacteria isolated from different tissues of tomato plants were analyzed for the effects of their growth-promoting activities on the germination and growth of tomato plants.The bacteria with growth-promoting activity were preliminarily identified.[Result]Totally 59 endophytic bacterial strains were isolated from roots and stems of tomatoes,of which 4 showed significantly growth-promoting activity to germination and growth of tomato.The results suggest that these strains are endowed with the potential capability of growth-promoting.[Conclusion]The endophytic bacteria with growth-promoting activity were found among the isolates from tomato plants.This provided a good foundation for utilization of these bacteria with growth-promoting activity.展开更多
[ Objective ] The paper was to study the growth-promoting and antagonistic action of endophytic bacteria strains Itb57 and Itb295 of tobacco to explore their functions in biological control. [ Method] The growth-promo...[ Objective ] The paper was to study the growth-promoting and antagonistic action of endophytic bacteria strains Itb57 and Itb295 of tobacco to explore their functions in biological control. [ Method] The growth-promoting effects of bacterial suspension ~ff endophytic bacteria Itb57 and Itb295 on tobacco seedling un- der different treatment modes were studied using potting method in greenhouse. The antagonistic action of bacterial suspension of endophytic bacteria Itb57 and Itb295 on Phytophthora nicotianae, Alternaria alternata and Botrytis cinerea were measured by duel culture method. [ Result] Bacterial suspensions of enduphytic bacteria Itb57 and Itb295 had certain growth-promoting effects on tobacco seedling, which could significantly increase the fresh weight and dry weight in aerial part; the growth-promoting effect of soaking ＋ spraying and irrigating treatment was the best. Itb57 strain had good antagonistic action against P. nicotianae. A. alterna- ta and B. cinerea, while Itb295 strain only had good antifungal effect against P. nicotianae. [ Conclusion] The results provided basis for the study and application of tobacco endophytic bacteria strains Itb57 and Itb295 in biocontrol of tobacco diseases.展开更多
Salinity is one of the most important growth-limiting factors for most crops in arid and semi-arid regions;however,the use of plant growth-promoting rhizobacteria isolated from saline soils could reduce the effects of...Salinity is one of the most important growth-limiting factors for most crops in arid and semi-arid regions;however,the use of plant growth-promoting rhizobacteria isolated from saline soils could reduce the effects of saline stress in crops.This study aimed to evaluate the efficiency of plant growth-promoting rhizobacteria(PGPRs),isolated from the rhizosphere of halophile plants,for the growth,Na^+/K^+balance,ethylene emission,and gene expression of wheat seedlings{Triticum aestivum L.)grown under saline conditions(100 mmol L^-1 NaCl)for 14 d.A total of 118 isolates obtained from saline soils of the deserts of Iran were tested for their capacity as PGPRs.Out of the 118 isolates,17 could solubilize phosphate(Ca3(P〇4)2),5 could produce siderophores,and 16 could synthesize indole-3-acetic acid.Additionally,PGPRs were also evaluated for aminocyclopropane-l-carboxylate deaminase activity.A pot experiment was conducted to evaluate the ability of 28 PGPR isolates to promote growth,regulate Na^+/K^+balance,and decrease ethylene emissions in plants.The most efficient PGPRs were Arthrobacter aurescens.Bacillus atrophaeus,Enterobacter ashuriae,and Pseudomonas fluorescens.Gene expression analysis revealed the up-regulation of H^+-PPase,HKT1,NHX7,CAT,and APX expression in roots of Enterobacter-inocuVdied salt-stressed plants.Salt-tolerant rhizobacteria exhibiting plant growth-promoting traits can facilitate the growth of wheat plants under saline conditions.Our results indicate that the isolation of these bacteria may be useful for formulating new inoculants to improve wheat cropping systems in saline soils.展开更多
Bacterial ability to colonize the rhizosphere of plants in arsenic（As） contaminated soils is highly important for symbiotic and free-living plant growth-promoting rhizobacteria（PGPR）used as inoculants, since they ...Bacterial ability to colonize the rhizosphere of plants in arsenic（As） contaminated soils is highly important for symbiotic and free-living plant growth-promoting rhizobacteria（PGPR）used as inoculants, since they can contribute to enhance plant As tolerance and limit metalloid uptake by plants. The aim of this work was to study the effect of As on growth,exopolysaccharide（EPS） production, biofilm formation and motility of two strains used as soybean inoculants, Bradyrhizobium japonicum E109 and Azospirillum brasilense Az39. The metabolism of arsenate（As（V）） and arsenite（As（III）） and their removal and/or possible accumulation were also evaluated. The behavior of both bacteria under As treatment was compared and discussed in relation to their potential for colonizing plant rhizosphere with high content of the metalloid. B. japonicum E109 growth was reduced with As（III）concentration from 10 μM while A. brasilense Az39 showed a reduction of growth with As（III） from 500 μM. EPS and biofilm production increased significantly under 25 μM As（III）for both strains. Moreover, this was more notorious for Azospirillum under 500 μM As（III）,where motility was seriously affected. Both bacterial strains showed a similar ability to reduce As（V）. However, Azospirillum was able to oxidize more As（III）（around 53%） than Bradyrhizobium（17%）. In addition, both strains accumulated As in cell biomass. The behavior of Azospirillum under As treatments suggests that this strain would be able to colonize efficiently As contaminated soils. In this way, inoculation with A. brasilense Az39 would positively contribute to promoting growth of different plant species under As treatment.展开更多
Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with t...Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with the plants.These bacteria viz.,Agrobacterium,Arthobacter,Azospirillum,Bacillus,Burkholderia,Flavobacterium,Pseudomonas,Rhizobium,etc.,play important role in plant growth promotion.In addition,such symbiotic associations of PGPRs in the rhizospheric region also confer protection against several diseases caused by bacterial,fungal and viral pathogens.The biocontrol mechanism utilized by PGPR includes direct and indirect mechanisms direct PGPR mechanisms include the production of antibiotic,siderophore,and hydrolytic enzymes,competition for space and nutrients,and quorum sensing whereas,indirect mechanisms include rhizomicrobiome regulation via.secretion of root exudates,phytostimulation through the release of phytohormones viz.,auxin,cytokinin,gibberellic acid,1-aminocyclopropane-1-carboxylate and induction of systemic resistance through expression of antioxidant defense enzymes viz.,phenylalanine ammonia lyase(PAL),peroxidase(PO),polyphenyloxidases(PPO),superoxide dismutase(SOD),chitinase andβ-glucanases.For the suppression of plant diseases potent bio inoculants can be developed by modulating the rhizomicrobiome through rhizospheric engineering.In addition,understandings of different strategies to improve PGPR strains,their competence,colonization efficiency,persistence and its future implications should also be taken into consideration.展开更多
Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activ...Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activity have exacerbated salinization in arid and semi-arid regions,which in turn has led to the growth inhibition of halophytes,including N.tangutorum.Arbuscular mycorrhizal fungi(AMF)and plant growth-promoting rhizobacteria(PGPR)have the potential to improve the salt tolerance of plants and their adaptation to saline soil environments.In this study,the effects of single and combined inoculations of AMF(Glomus mosseae)and PGPR(Bacillus amyloliquefaciens FZB42)on N.tangutorum were evaluated in severe saline soil conditions.The results indicate that AMF and PGPR alone may not adapt well to the real soil environment,and cannot ensure the effect of either growth promotion or salt-tolerance induction on N.tangutorum seedlings.However,the combination of AMF and PGPR significantly promoted mycorrhizal colonization,increased biomass accumulation,improved morphological development,enhanced photosynthetic performance,stomatal adjustment ability,and the exchange of water and gas.Co-inoculation also significantly counteracted the adverse effect of salinity on the soil structure of N.tangutorum seedlings.It is concluded that the effectiveness of microbial inoculation on the salt tolerance of N.tangutorum seedlings depends on the functional compatibility between plants and microorganisms as well as the specific combinations of AMF and PGPR.展开更多
Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise ...Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise were identified to five genera Dyella,Luteimonas,Euterobacter,Paraburkholderia and Bacillus based on the sequences of16 S rRNA gene.All the strains were isolated from nondisturbed stands.These bacteria significantly decreased germination time and increased sprout sizes.Indole acetic acid and gibberellin production and phosphate solubilisation were detected.Results indicate that these biochemicals could be essential for P.chiapensis distribution and suggest the possibility that PGPR inoculation on P.chiapensis seeds prior to planting could improve germination and possibly seedling development.展开更多
Various microorganisms live in association with different parts of plants and can be harmful,neutral,or beneficial to plant health.Some microbial inhabitants of plants can control plant diseases by contesting with,pre...Various microorganisms live in association with different parts of plants and can be harmful,neutral,or beneficial to plant health.Some microbial inhabitants of plants can control plant diseases by contesting with,predating on,or antagonizing plant pathogens and by inducing systems for plant defense.A range of methods,including plant growth-promoting microorganisms(PGPMs)as biological control agents(BCAs)(BCA-PGPMs)are used for the biological management and control of plant pathogens.Some BCAs interact with plants by inducing resistance or priming plants without direct interaction with the pathogen.Other BCAs operate via nutrient competition or other mechanisms to modulate the growth conditions for the pathogen.Generally,PGPMs can be applied alone or together with other chemicals or carriers to control various crop diseases.This review highlights the effective types of BCA-PGPMs and their applications,roles,carrier based-formulations,and responses to rice(Oryza sativa L.)pathogens.Future plant disease management prospects are promising,and growers’increasing demand for BCA-PGPM products can be exploited as an effective approach to the management of plant diseases,as well as to improve yield,environmental protection,biological resources,and agricultural system sustainability.展开更多
[Objectives] This study was conducted to explore the interaction between nitrogen-fixing and phosphate-solubilizing strains and the optimal combination of different functional strains,in order to provide a theoretical...[Objectives] This study was conducted to explore the interaction between nitrogen-fixing and phosphate-solubilizing strains and the optimal combination of different functional strains,in order to provide a theoretical basis for the development of PGPR compound fertilizers suitable for local environment.[Methods] In this study,16S rDNA gene sequence analysis was used to identify fast-growing and competitive strains from pasture nodules and rhizosphere soils in Guizhou Province,and three representative Rhizobia and phosphorus-solubilizing bacteria were chosen for the test of bacterial combination when reducing 50% of nitrogen and 30% of phosphorus.The effects of different strain combinations on the plant height,root length,aboveground and underground biomass of Lotus corniculatus L.were investigated,and the total nitrogen and total phosphorus contents of the plants were determined.[Results] The mixed bacterial agents could promote the increase of root biomass,and the effects of A1,A3,B3 and C3 were the most obvious.The fresh weight and dry weight of the roots of L.corniculatus increased by 30.35%-168.45% and 26.43%-180.00%,respectively,and A3,B3,B2 and C3 had the best effects.The total phosphorus content of the plants increased by 12.79%-55.25% compared with the CK2;and most of the bacterial agents with significant growth-promoting effects showed decreased total nitrogen contents,while those with non-significant growth-promoting effects showed significantly-increased total nitrogen contents,which were not as much as the CK1.Comprehensively,the most productive combination was C3,namely R27-2 Rhinohizobium fredii and P33-3 Stenotrophomonas rhizophila.[Conclusions] This study can provide a theoretical basis for the production and promotion of bacterial fertilizers.展开更多
Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture,...Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha−1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies.展开更多
Endophytes,as crucial components of plant microbial communities,significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts,promote plant growth,and degrade pathoge...Endophytes,as crucial components of plant microbial communities,significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts,promote plant growth,and degrade pathogenic fungal mycelia.In this study,an experiment was conducted in August 2022 to explore the growth-promoting potential of endophytic bacterial strains isolated from two medical plant species,Thymus altaicus and Salvia deserta,using a series of screening media.Plant samples of Thymus altaicus and Salvia deserta were collected from Zhaosu County and Habahe County in Xinjiang Uygur Autonomous Region,China,in July 2021.Additionally,the inhibitory effects of endophytic bacterial strains on the four pathogenic fungi(Fusarium oxysporum,Fulvia fulva,Alternaria solani,and Valsa mali)were determined through the plate confrontation method.A total of 80 endophytic bacterial strains were isolated from Thymus altaicus,while a total of 60 endophytic bacterial strains were isolated from Salvia deserta.The endophytic bacterial strains from both Thymus altaicus and Salvia deserta exhibited plant growth-promoting properties.Specifically,the strains of Bacillus sp.TR002,Bacillus sp.TR005,Microbacterium sp.TSB5,and Rhodococcus sp.TR013 demonstrated strong cellulase-producing activity,siderophore-producing activity,phosphate solubilization activity,and nitrogen-fixing activity,respectively.Out of 140 endophytic bacterial strains isolated from Thymus altaicus and Salvia deserta,104 strains displayed anti-fungal activity against Fulvia fulva,Alternaria solani,Fusarium oxysporum,and Valsa mali.Furthermore,the strains of Bacillus sp.TR005,Bacillus sp.TS003,and Bacillus sp.TSB7 exhibited robust inhibition rates against all the four pathogenic fungi.In conclusion,the endophytic bacterial strains from Thymus altaicus and Salvia deserta possess both plant growth-promoting and anti-fungal properties,making them promising candidates for future development as growth-promoting agents and biocontrol tools for plant diseases.展开更多
Plant growth-promoting bacteria(PGPBs)can promote plant growth and improve crop yield.They can induce plant systemic resistance to resist biotic and abiotic stresses.In recent years,with the development of green ecolo...Plant growth-promoting bacteria(PGPBs)can promote plant growth and improve crop yield.They can induce plant systemic resistance to resist biotic and abiotic stresses.In recent years,with the development of green ecological agriculture,new biological fertilizers such as microbial inocula and microbial fertilizers based on PGPBs have been gradually applied in crop planting.Based on plant growth promotion and disease control,the application progress of PGPBs in crops from the aspects of growth promotion mechanism,growth promotion effect,resistance to biological and abiotic stresses were discussed,aiming to provide reference for the relevant research and application of PGPBs in crops.展开更多
Outdoor green walls are gaining popularity for enhancing building aesthetics and promoting healthy and sustainable urban environment.However,concerns about their high water consumption in the context of ongoing water ...Outdoor green walls are gaining popularity for enhancing building aesthetics and promoting healthy and sustainable urban environment.However,concerns about their high water consumption in the context of ongoing water crises highlight the need for alternative water sources,such as recycled water.This research investigated the effects of recycled water irrigation and plant growth-promoting bacteria(PGPB)on four plant species for green walls in Mashhad,Iran:Festuca ovina,Ophiopogon japonicus,Aptenia cordifolia,and Carpobrotus edulis.Over nine months(March to December 2022),researchers conducted experiments using three water types(graywater,wastewater,and urban water)as the main factor and four bacterial treatments(Mix B1,Mix B2,Mix B3,and a control)as the sub-factor,with three replications of split-plot layout based on a randomized complete block design.Results showed significant differences in aesthetic qualities,with optimal visual quality achieved by applying Mix B2 or B3 with wastewater for Aptenia cordifolia,Carpobrotus edulis,and Festuca ovina;and Ophiopogon japonicus performed best with Mix B1 and graywater.The research highlights the potential of using Aptenia cordifolia with Mix B3 and wastewater irrigation for outdoor green walls,especially in arid and semi-arid climates.展开更多
Fulminant hepatitis is a serious and complex disease with high mortality. In recent years, hepatocyte growth-promoting factors (pHGF), developed on the basis of fetal liver cell injection, has been jointly used as a c...Fulminant hepatitis is a serious and complex disease with high mortality. In recent years, hepatocyte growth-promoting factors (pHGF), developed on the basis of fetal liver cell injection, has been jointly used as a comprehensive therapy for fulminant hepatitis. The following is a report of the results of using pHGF for the treatment of 1687 cases of fulminant hepatitis (with 1196 controls).展开更多
Plant growth-promoting rhizobacteria(PGPR)have been widely used for the promotion of plant performance.Predatory protists can influence the taxonomic and functional composition of rhizosphere bacteria.However,research...Plant growth-promoting rhizobacteria(PGPR)have been widely used for the promotion of plant performance.Predatory protists can influence the taxonomic and functional composition of rhizosphere bacteria.However,research on the impact of the interaction between protist and PGPR on plant performance remains at a very early stage.Here,we examined the impacts of individual inoculation of protist(Colpoda inflata,Dimastigella trypaniformis,or Vermamoeba vermiformis)or the PGPR strain Bacillus velezensis SQR9 as well as the co-inoculation of the protist C.inflata and B.velezensis SQR9 on the growth of tomato plants.We found that all individual protists and Bacillus could promote plant growth compared to the control with no microbe inoculation,with the co-inoculation of C.inflata and B.velezensis SQR9 achieving the greatest performance,including plant height,fresh weight,and dry weight.Different protists harbored distinct rhizosphere bacterial communities,with the co-inoculation of protist and Bacillus resulting in the lowest bacterial diversity and driving significant changes in community structure and composition,particularly by increasing the relative abundance of Proteobacteria.Random forest model highlighted Cellvibrio as the most important bacterial predictor of plant growth,which was enriched after protist inoculation,especially after the mixed inoculation of protist and Bacillus.We further found that bacterial functional genes of nitrogen metabolism were the key determinants of plant growth.These results indicate that the interaction between protists and Bacillus can support plant growth by reshaping rhizosphere bacterial community composition and function.Understanding the interaction mechanisms between protist and PGPR is crucial for their effective utilization in sustainable agriculture.展开更多
Rice yield in the black soil region of Northeast China has been declining due to severe soil fertility degradation caused by both biotic and abiotic factors.Artificial humic substance(A-HS)has attracted much attention...Rice yield in the black soil region of Northeast China has been declining due to severe soil fertility degradation caused by both biotic and abiotic factors.Artificial humic substance(A-HS)has attracted much attention due to its high cost-effectiveness and great potential to improve soil fertility.However,the specific effects of A-HS on nutrient contents in rice nursery soils remain unclear.This study systematically investigated the effects of rational application of A-HS on soil nutrient turnover and yield and analyzed the changes in soil nutrients and microbial communities at Qianfeng Farm,Northeast China.The results indicated that the application of A-HS significantly increased soil dissolved organic matter and nutrient contents in the native and seedling soils.In addition,the root growth and yield of the seedlings at maturity were effectively promoted.More interestingly,the application of A-HS significantly altered plant growth-promoting rhizobacteria,such as Noviherbaspirillum,Klebsiella,and Pedobacter,improving natural barrier formation and soil nutrient conversion.It could be concluded that A-HS significantly enhanced crop nutrient uptake and accumulation by altering soil bacterial communities.In general,the application of A-HS could be profitable and sustainable in rice production.The current study from multiple aspects provides valuable insights into the benefits of A-HS in promoting crop growth and development,which could have important implications for agriculture and food security.展开更多
Salinity is a major environmental stress affecting crop growth and productivity globally.The application of halotolerant plant growth-promoting bacteria(HT-PGPB)has been widely recognized to promote crop growth and re...Salinity is a major environmental stress affecting crop growth and productivity globally.The application of halotolerant plant growth-promoting bacteria(HT-PGPB)has been widely recognized to promote crop growth and reduce the adverse effects of salt stress.In this study,key endophytic bacteria that can respond to salinity changes were identified by analyzing the microbial community in propagules of Kandelia obovata.Delftia tsuruhatensis DYX29,a strain that can grow normally under high salinity conditions with a sodium chloride(NaCl)concentration of 5%(w/v),was obtained by pure culture.DYX29 can produce siderophores with a siderophore unit value of 87.6%and 1-aminocyclopropane-1-carboxylate(ACC)deaminase with 29 UL^(-1),and its synthesis of intracellular amino acids and auxin can be induced by high salinity.Inoculation with DYX29 can remarkably promote the salt tolerance of rice.Under salt stress,the addition of DYX29 was shown to effectively promote the growth of rice seedlings through a variety of approaches.It increased the biomass of rice seedlings by 32.9%(dry weight)and promoted the accumulation of soluble sugars by 23.1%.It also increased catalase(CAT)and peroxidase(POD)activities in rice leaves by 37.8 and 88.2%,respectively.Moreover,it maintained the ionic homeostasis in rice roots and leaves.In addition,it upregulated the expression of growth-promoting hormones,such as indole-3-acetic acid(IAA),brassinolide(BL),abscisic acid(ABA),and salicylic acid(SA),in rice roots by 27.8,69.5,123.7 and 28.6%,respectively.This study provides inspiration for screening valuable salt-tolerant pro-biotic bacteria from mangrove ecosystems and their use for crop growth promotion under salt stress.It can also provide useful references for the development of new salt-tolerant and pro-biotic biofertilizers,as well as the investigation of the related mechanisms.展开更多
Continuous cropping leads to high incidence of soilborne diseases such as bacterial wilt caused by Ralstonia solanacearum,which poses a risk to agricultural production.Anaerobic soil disinfestation(ASD)and plant growt...Continuous cropping leads to high incidence of soilborne diseases such as bacterial wilt caused by Ralstonia solanacearum,which poses a risk to agricultural production.Anaerobic soil disinfestation(ASD)and plant growthpromoting rhizobacteria(PGPR)are considered environmentally friendly methods to control bacterial wilt.However,the underlying mechanism of the improvement of soil health and the inhibition of bacterial wilt after ASD treatment and PGPR inoculation needs further exploration.This study evaluated the effect of ASD treatment on soil improvement at pre-planting of tomato,and the effect of ASD treatment combined with the application of Bacillus velezensis Y6(BV)on soil quality,R.solanacearum abundance,and bacterial communities at 90 days before harvesting of tomato.The results showed that ASD treatment reduced R.solanacearum abundance in soil by17.6%at pre-planting and 18.7%at 90 days before harvesting,but BV inoculation did not influence R.solanacearum abundance.ASD and ASD+BV treatments effectively reduced the occurrence of bacterial wilt,improved soil nutrient status and increased soil microbial activity at 90 days before harvesting.Principal co-ordinate analysis showed that the soil bacterial community was significantly influenced by ASD treatment both at pre-planting and at 90 days before harvesting.Further investigation found that ASD contributed to the enrichment of beneficial flora(Bacillus and Streptomyces).Moreover,pH was an important environmental factor affecting the abundance of R.solanacearum in soil.Co-occurrence network analysis showed that ASD treatment significantly increased network connection of bacterial communities and the proportion of beneficial microorganisms(Proteobacteria and Firmicutes),leading to complex soil bacterial co-occurrence networks both at pre-planting and at 90 days before harvesting.Collectively,these results indicate that ASD treatment,but not microbial inoculation can enhance tomato plant resistance to bacterial wilt by improving soil quality and modulating the soil bacterial community.展开更多
Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolera...Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.展开更多
Enhancing the growth of alfalfa(Medicago sativa L.)through inoculation with rhizobacteria represents a sustainable strategy for reclaiming saline soils.However,the lack of suitable strains and practical application gu...Enhancing the growth of alfalfa(Medicago sativa L.)through inoculation with rhizobacteria represents a sustainable strategy for reclaiming saline soils.However,the lack of suitable strains and practical application guidelines poses significant challenges to the utilization of Plant Growth-Promoting Rhizobacteria(PGPR)in saltaffected soils of Northwest China.In this study,we selected four PGPR strains derived from indigenous halophytes based on their growth-promoting characteristics.These strains underwent further selection via a petri dish assay.Subsequently,the effects of the selected PGPR strains on alfalfa growth and soil fertility were rigorously examined through pot trials.The results demonstrated that Bacillus filamentosus HL3,B.filamentosus HL6,Bacillus subtilis subsp.stercoris HG12,and Paenibacillus peoriae HG24 significantly produced indole-3-acetic acid(IAA),solubilized phosphorus,and fixed nitrogen(except for B.filamentosus HL6,which did not significantly fix nitrogen).Compared to non-inoculated plants,B.filamentosus HL6 and B.subtilis subsp.stercoris HG12 significantly enhanced seed germination,root elongation,and seedling biomass in a 150 mmol/L NaCl saline solution.In saline-alkaline soils,PGPR inoculation under brackish water irrigation did not restore alfalfa growth to the levels observed under freshwater irrigation.Principal Component Analysis(PCA)condensed ten indicators into two indices,explaining 86.85%of the variance.Using these two indices as weights,an evaluation model for the PGPR-alfalfa symbiosis indicated that B.subtilis subsp.stercoris HG12 had the most substantial effect under freshwater irrigation,while co-inoculation with B.subtilis subsp.stercoris HG12 and B.filamentosus HL6 had the most significant impact on alfalfa growth and soil improvement under brackish water irrigation.Available phosphorus was identified as the primary factor influencing alfalfa growth,contributing 82.3%to the growth variation.These findings provide suitable microbial strains for the utilization of saline-alkali land and underscore the potential of applying indigenous PGPR-alfalfa symbiotic techniques to improve soil fertility and crop yield in the arid regions of Northwest China.展开更多
基金Supported by the Science Foundation for the Introduced High-level Talents in Anhui Agricultural University(yj2008-1)~~
文摘[Objective] The study aimed to investigate the growth-promoting activities of endophytic bacteria from tomato plants.[Method]The endophytic bacteria isolated from different tissues of tomato plants were analyzed for the effects of their growth-promoting activities on the germination and growth of tomato plants.The bacteria with growth-promoting activity were preliminarily identified.[Result]Totally 59 endophytic bacterial strains were isolated from roots and stems of tomatoes,of which 4 showed significantly growth-promoting activity to germination and growth of tomato.The results suggest that these strains are endowed with the potential capability of growth-promoting.[Conclusion]The endophytic bacteria with growth-promoting activity were found among the isolates from tomato plants.This provided a good foundation for utilization of these bacteria with growth-promoting activity.
基金Supported by Natural Science Foundation of Chongqing City(CSTC,2009BB1294)~~
文摘[ Objective ] The paper was to study the growth-promoting and antagonistic action of endophytic bacteria strains Itb57 and Itb295 of tobacco to explore their functions in biological control. [ Method] The growth-promoting effects of bacterial suspension ~ff endophytic bacteria Itb57 and Itb295 on tobacco seedling un- der different treatment modes were studied using potting method in greenhouse. The antagonistic action of bacterial suspension of endophytic bacteria Itb57 and Itb295 on Phytophthora nicotianae, Alternaria alternata and Botrytis cinerea were measured by duel culture method. [ Result] Bacterial suspensions of enduphytic bacteria Itb57 and Itb295 had certain growth-promoting effects on tobacco seedling, which could significantly increase the fresh weight and dry weight in aerial part; the growth-promoting effect of soaking ＋ spraying and irrigating treatment was the best. Itb57 strain had good antagonistic action against P. nicotianae. A. alterna- ta and B. cinerea, while Itb295 strain only had good antifungal effect against P. nicotianae. [ Conclusion] The results provided basis for the study and application of tobacco endophytic bacteria strains Itb57 and Itb295 in biocontrol of tobacco diseases.
基金This work was supported scientifically by COST Action ESI406“Soil fauna-Key to Soil Organic Matter Dynamics and Modelling(KEYSOM)”.
文摘Salinity is one of the most important growth-limiting factors for most crops in arid and semi-arid regions;however,the use of plant growth-promoting rhizobacteria isolated from saline soils could reduce the effects of saline stress in crops.This study aimed to evaluate the efficiency of plant growth-promoting rhizobacteria(PGPRs),isolated from the rhizosphere of halophile plants,for the growth,Na^+/K^+balance,ethylene emission,and gene expression of wheat seedlings{Triticum aestivum L.)grown under saline conditions(100 mmol L^-1 NaCl)for 14 d.A total of 118 isolates obtained from saline soils of the deserts of Iran were tested for their capacity as PGPRs.Out of the 118 isolates,17 could solubilize phosphate(Ca3(P〇4)2),5 could produce siderophores,and 16 could synthesize indole-3-acetic acid.Additionally,PGPRs were also evaluated for aminocyclopropane-l-carboxylate deaminase activity.A pot experiment was conducted to evaluate the ability of 28 PGPR isolates to promote growth,regulate Na^+/K^+balance,and decrease ethylene emissions in plants.The most efficient PGPRs were Arthrobacter aurescens.Bacillus atrophaeus,Enterobacter ashuriae,and Pseudomonas fluorescens.Gene expression analysis revealed the up-regulation of H^+-PPase,HKT1,NHX7,CAT,and APX expression in roots of Enterobacter-inocuVdied salt-stressed plants.Salt-tolerant rhizobacteria exhibiting plant growth-promoting traits can facilitate the growth of wheat plants under saline conditions.Our results indicate that the isolation of these bacteria may be useful for formulating new inoculants to improve wheat cropping systems in saline soils.
基金PPI (SECy T-UNRC) (18/C418), CONICET, MINCy T Córdoba and PICT (FONCy T-SECy T-UNRC) (1568/10) for financial support
文摘Bacterial ability to colonize the rhizosphere of plants in arsenic（As） contaminated soils is highly important for symbiotic and free-living plant growth-promoting rhizobacteria（PGPR）used as inoculants, since they can contribute to enhance plant As tolerance and limit metalloid uptake by plants. The aim of this work was to study the effect of As on growth,exopolysaccharide（EPS） production, biofilm formation and motility of two strains used as soybean inoculants, Bradyrhizobium japonicum E109 and Azospirillum brasilense Az39. The metabolism of arsenate（As（V）） and arsenite（As（III）） and their removal and/or possible accumulation were also evaluated. The behavior of both bacteria under As treatment was compared and discussed in relation to their potential for colonizing plant rhizosphere with high content of the metalloid. B. japonicum E109 growth was reduced with As（III）concentration from 10 μM while A. brasilense Az39 showed a reduction of growth with As（III） from 500 μM. EPS and biofilm production increased significantly under 25 μM As（III）for both strains. Moreover, this was more notorious for Azospirillum under 500 μM As（III）,where motility was seriously affected. Both bacterial strains showed a similar ability to reduce As（V）. However, Azospirillum was able to oxidize more As（III）（around 53%） than Bradyrhizobium（17%）. In addition, both strains accumulated As in cell biomass. The behavior of Azospirillum under As treatments suggests that this strain would be able to colonize efficiently As contaminated soils. In this way, inoculation with A. brasilense Az39 would positively contribute to promoting growth of different plant species under As treatment.
文摘Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with the plants.These bacteria viz.,Agrobacterium,Arthobacter,Azospirillum,Bacillus,Burkholderia,Flavobacterium,Pseudomonas,Rhizobium,etc.,play important role in plant growth promotion.In addition,such symbiotic associations of PGPRs in the rhizospheric region also confer protection against several diseases caused by bacterial,fungal and viral pathogens.The biocontrol mechanism utilized by PGPR includes direct and indirect mechanisms direct PGPR mechanisms include the production of antibiotic,siderophore,and hydrolytic enzymes,competition for space and nutrients,and quorum sensing whereas,indirect mechanisms include rhizomicrobiome regulation via.secretion of root exudates,phytostimulation through the release of phytohormones viz.,auxin,cytokinin,gibberellic acid,1-aminocyclopropane-1-carboxylate and induction of systemic resistance through expression of antioxidant defense enzymes viz.,phenylalanine ammonia lyase(PAL),peroxidase(PO),polyphenyloxidases(PPO),superoxide dismutase(SOD),chitinase andβ-glucanases.For the suppression of plant diseases potent bio inoculants can be developed by modulating the rhizomicrobiome through rhizospheric engineering.In addition,understandings of different strategies to improve PGPR strains,their competence,colonization efficiency,persistence and its future implications should also be taken into consideration.
基金the National Key Research and Development Program of China(No.2017YFE0119100)the National Natural Science Foundation of China(No.42107513)the Key Research and Development Program of Gansu(No.21YF5FA151)。
文摘Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activity have exacerbated salinization in arid and semi-arid regions,which in turn has led to the growth inhibition of halophytes,including N.tangutorum.Arbuscular mycorrhizal fungi(AMF)and plant growth-promoting rhizobacteria(PGPR)have the potential to improve the salt tolerance of plants and their adaptation to saline soil environments.In this study,the effects of single and combined inoculations of AMF(Glomus mosseae)and PGPR(Bacillus amyloliquefaciens FZB42)on N.tangutorum were evaluated in severe saline soil conditions.The results indicate that AMF and PGPR alone may not adapt well to the real soil environment,and cannot ensure the effect of either growth promotion or salt-tolerance induction on N.tangutorum seedlings.However,the combination of AMF and PGPR significantly promoted mycorrhizal colonization,increased biomass accumulation,improved morphological development,enhanced photosynthetic performance,stomatal adjustment ability,and the exchange of water and gas.Co-inoculation also significantly counteracted the adverse effect of salinity on the soil structure of N.tangutorum seedlings.It is concluded that the effectiveness of microbial inoculation on the salt tolerance of N.tangutorum seedlings depends on the functional compatibility between plants and microorganisms as well as the specific combinations of AMF and PGPR.
基金supported by SEP,Grant DSA/103.5/15/10976 and VIEP-BUAP,Grant 20 Sub-Program。
文摘Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise were identified to five genera Dyella,Luteimonas,Euterobacter,Paraburkholderia and Bacillus based on the sequences of16 S rRNA gene.All the strains were isolated from nondisturbed stands.These bacteria significantly decreased germination time and increased sprout sizes.Indole acetic acid and gibberellin production and phosphate solubilisation were detected.Results indicate that these biochemicals could be essential for P.chiapensis distribution and suggest the possibility that PGPR inoculation on P.chiapensis seeds prior to planting could improve germination and possibly seedling development.
基金Raiganj University,IndiaInstituto Tecnológico de Sonora,México+7 种基金Campo Experimental Norman E.Borlaug-Instituto Nacional de Investigaciones Forestales,Agrícolas y Pecuarias(INIFAP),MéxicoUniversidad Nacional Experimental del Táchira,VenezuelaFederal University of Pernambuco,BrazilFederal University of Agriculture,NigeriaUniversity of Tabriz,IranIndian Council of Agricultural Research(ICAR)-National Rice Research Institute for supportthe Government of West Bengal,India for the Swami Vivekananda Merit Cum Means Ph.D.Scholarship(No.WBP191584588825)the Department of Science and Technology(DST),India for Inspire Fellowship(No.IF190457)。
文摘Various microorganisms live in association with different parts of plants and can be harmful,neutral,or beneficial to plant health.Some microbial inhabitants of plants can control plant diseases by contesting with,predating on,or antagonizing plant pathogens and by inducing systems for plant defense.A range of methods,including plant growth-promoting microorganisms(PGPMs)as biological control agents(BCAs)(BCA-PGPMs)are used for the biological management and control of plant pathogens.Some BCAs interact with plants by inducing resistance or priming plants without direct interaction with the pathogen.Other BCAs operate via nutrient competition or other mechanisms to modulate the growth conditions for the pathogen.Generally,PGPMs can be applied alone or together with other chemicals or carriers to control various crop diseases.This review highlights the effective types of BCA-PGPMs and their applications,roles,carrier based-formulations,and responses to rice(Oryza sativa L.)pathogens.Future plant disease management prospects are promising,and growers’increasing demand for BCA-PGPM products can be exploited as an effective approach to the management of plant diseases,as well as to improve yield,environmental protection,biological resources,and agricultural system sustainability.
基金Supported by Guizhou Province Science and Technology Support Program(QKHZC[2016]2504,[2019]2359)
文摘[Objectives] This study was conducted to explore the interaction between nitrogen-fixing and phosphate-solubilizing strains and the optimal combination of different functional strains,in order to provide a theoretical basis for the development of PGPR compound fertilizers suitable for local environment.[Methods] In this study,16S rDNA gene sequence analysis was used to identify fast-growing and competitive strains from pasture nodules and rhizosphere soils in Guizhou Province,and three representative Rhizobia and phosphorus-solubilizing bacteria were chosen for the test of bacterial combination when reducing 50% of nitrogen and 30% of phosphorus.The effects of different strain combinations on the plant height,root length,aboveground and underground biomass of Lotus corniculatus L.were investigated,and the total nitrogen and total phosphorus contents of the plants were determined.[Results] The mixed bacterial agents could promote the increase of root biomass,and the effects of A1,A3,B3 and C3 were the most obvious.The fresh weight and dry weight of the roots of L.corniculatus increased by 30.35%-168.45% and 26.43%-180.00%,respectively,and A3,B3,B2 and C3 had the best effects.The total phosphorus content of the plants increased by 12.79%-55.25% compared with the CK2;and most of the bacterial agents with significant growth-promoting effects showed decreased total nitrogen contents,while those with non-significant growth-promoting effects showed significantly-increased total nitrogen contents,which were not as much as the CK1.Comprehensively,the most productive combination was C3,namely R27-2 Rhinohizobium fredii and P33-3 Stenotrophomonas rhizophila.[Conclusions] This study can provide a theoretical basis for the production and promotion of bacterial fertilizers.
文摘Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha−1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies.
基金financially supported by the Third Xinjiang Comprehensive Scientific Expedition (2022xjkk020605)the Xinjiang Uygur Autonomous Region Regional Coordinated Innovation Project (Shanghai Cooperation Organization Science and Technology Partnership Program) (2020E01047)supported by the Introduction Project of High-level Talents in Xinjiang Uygur Autonomous Region, China
文摘Endophytes,as crucial components of plant microbial communities,significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts,promote plant growth,and degrade pathogenic fungal mycelia.In this study,an experiment was conducted in August 2022 to explore the growth-promoting potential of endophytic bacterial strains isolated from two medical plant species,Thymus altaicus and Salvia deserta,using a series of screening media.Plant samples of Thymus altaicus and Salvia deserta were collected from Zhaosu County and Habahe County in Xinjiang Uygur Autonomous Region,China,in July 2021.Additionally,the inhibitory effects of endophytic bacterial strains on the four pathogenic fungi(Fusarium oxysporum,Fulvia fulva,Alternaria solani,and Valsa mali)were determined through the plate confrontation method.A total of 80 endophytic bacterial strains were isolated from Thymus altaicus,while a total of 60 endophytic bacterial strains were isolated from Salvia deserta.The endophytic bacterial strains from both Thymus altaicus and Salvia deserta exhibited plant growth-promoting properties.Specifically,the strains of Bacillus sp.TR002,Bacillus sp.TR005,Microbacterium sp.TSB5,and Rhodococcus sp.TR013 demonstrated strong cellulase-producing activity,siderophore-producing activity,phosphate solubilization activity,and nitrogen-fixing activity,respectively.Out of 140 endophytic bacterial strains isolated from Thymus altaicus and Salvia deserta,104 strains displayed anti-fungal activity against Fulvia fulva,Alternaria solani,Fusarium oxysporum,and Valsa mali.Furthermore,the strains of Bacillus sp.TR005,Bacillus sp.TS003,and Bacillus sp.TSB7 exhibited robust inhibition rates against all the four pathogenic fungi.In conclusion,the endophytic bacterial strains from Thymus altaicus and Salvia deserta possess both plant growth-promoting and anti-fungal properties,making them promising candidates for future development as growth-promoting agents and biocontrol tools for plant diseases.
基金Supported by Hebei Provincial Key R&D projects(21327306D)Hebei Provincial Key R&D projects(20326807D)Chengde Science and Technology Research and Development Planning Project(202103B003).
文摘Plant growth-promoting bacteria(PGPBs)can promote plant growth and improve crop yield.They can induce plant systemic resistance to resist biotic and abiotic stresses.In recent years,with the development of green ecological agriculture,new biological fertilizers such as microbial inocula and microbial fertilizers based on PGPBs have been gradually applied in crop planting.Based on plant growth promotion and disease control,the application progress of PGPBs in crops from the aspects of growth promotion mechanism,growth promotion effect,resistance to biological and abiotic stresses were discussed,aiming to provide reference for the relevant research and application of PGPBs in crops.
文摘Outdoor green walls are gaining popularity for enhancing building aesthetics and promoting healthy and sustainable urban environment.However,concerns about their high water consumption in the context of ongoing water crises highlight the need for alternative water sources,such as recycled water.This research investigated the effects of recycled water irrigation and plant growth-promoting bacteria(PGPB)on four plant species for green walls in Mashhad,Iran:Festuca ovina,Ophiopogon japonicus,Aptenia cordifolia,and Carpobrotus edulis.Over nine months(March to December 2022),researchers conducted experiments using three water types(graywater,wastewater,and urban water)as the main factor and four bacterial treatments(Mix B1,Mix B2,Mix B3,and a control)as the sub-factor,with three replications of split-plot layout based on a randomized complete block design.Results showed significant differences in aesthetic qualities,with optimal visual quality achieved by applying Mix B2 or B3 with wastewater for Aptenia cordifolia,Carpobrotus edulis,and Festuca ovina;and Ophiopogon japonicus performed best with Mix B1 and graywater.The research highlights the potential of using Aptenia cordifolia with Mix B3 and wastewater irrigation for outdoor green walls,especially in arid and semi-arid climates.
文摘Fulminant hepatitis is a serious and complex disease with high mortality. In recent years, hepatocyte growth-promoting factors (pHGF), developed on the basis of fetal liver cell injection, has been jointly used as a comprehensive therapy for fulminant hepatitis. The following is a report of the results of using pHGF for the treatment of 1687 cases of fulminant hepatitis (with 1196 controls).
基金supported by the National Natural Science Foundation of China(Nos.42377296 and 42107141)the National Key Research and Development Program of China(Nos.2023YFD1901402 and 2023YFD1901105)the Fundamental Research Funds for the Central Universities,China(No.YDZX2025046).
文摘Plant growth-promoting rhizobacteria(PGPR)have been widely used for the promotion of plant performance.Predatory protists can influence the taxonomic and functional composition of rhizosphere bacteria.However,research on the impact of the interaction between protist and PGPR on plant performance remains at a very early stage.Here,we examined the impacts of individual inoculation of protist(Colpoda inflata,Dimastigella trypaniformis,or Vermamoeba vermiformis)or the PGPR strain Bacillus velezensis SQR9 as well as the co-inoculation of the protist C.inflata and B.velezensis SQR9 on the growth of tomato plants.We found that all individual protists and Bacillus could promote plant growth compared to the control with no microbe inoculation,with the co-inoculation of C.inflata and B.velezensis SQR9 achieving the greatest performance,including plant height,fresh weight,and dry weight.Different protists harbored distinct rhizosphere bacterial communities,with the co-inoculation of protist and Bacillus resulting in the lowest bacterial diversity and driving significant changes in community structure and composition,particularly by increasing the relative abundance of Proteobacteria.Random forest model highlighted Cellvibrio as the most important bacterial predictor of plant growth,which was enriched after protist inoculation,especially after the mixed inoculation of protist and Bacillus.We further found that bacterial functional genes of nitrogen metabolism were the key determinants of plant growth.These results indicate that the interaction between protists and Bacillus can support plant growth by reshaping rhizosphere bacterial community composition and function.Understanding the interaction mechanisms between protist and PGPR is crucial for their effective utilization in sustainable agriculture.
基金the financial support by the National Key Research and Development Program of China(No.2022YFD1500100)the National Natural Science Foundation of China(No.52279034)+5 种基金the Outstanding Youth Project of Heilongjiang Province,China(No.JQ2021D001)the Young Longjiang Scholar,China,the Science and Technology Project of Henan Province,China(No.252102321157)the Scientific Research Foundation for Doctoral Talents at Shangqiu Normal University,China(No.700125017)the Natural Science Foundation of Heilongjiang Province,China(No.LH2022D003)the Heilongjiang Postdoctoral Fund,China(No.LBH-Z21037)the Science and Technology Project of Henan Province,China(No.252102110185)。
文摘Rice yield in the black soil region of Northeast China has been declining due to severe soil fertility degradation caused by both biotic and abiotic factors.Artificial humic substance(A-HS)has attracted much attention due to its high cost-effectiveness and great potential to improve soil fertility.However,the specific effects of A-HS on nutrient contents in rice nursery soils remain unclear.This study systematically investigated the effects of rational application of A-HS on soil nutrient turnover and yield and analyzed the changes in soil nutrients and microbial communities at Qianfeng Farm,Northeast China.The results indicated that the application of A-HS significantly increased soil dissolved organic matter and nutrient contents in the native and seedling soils.In addition,the root growth and yield of the seedlings at maturity were effectively promoted.More interestingly,the application of A-HS significantly altered plant growth-promoting rhizobacteria,such as Noviherbaspirillum,Klebsiella,and Pedobacter,improving natural barrier formation and soil nutrient conversion.It could be concluded that A-HS significantly enhanced crop nutrient uptake and accumulation by altering soil bacterial communities.In general,the application of A-HS could be profitable and sustainable in rice production.The current study from multiple aspects provides valuable insights into the benefits of A-HS in promoting crop growth and development,which could have important implications for agriculture and food security.
基金supported by funds from the National Natural Science Foundation of China(32270296)the Natural Science Foundation of Guangdong Province,China(2024A1515010498)+1 种基金the Shenzhen Postdoctoral Scientific Research,China(77000-42100004)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University,China。
文摘Salinity is a major environmental stress affecting crop growth and productivity globally.The application of halotolerant plant growth-promoting bacteria(HT-PGPB)has been widely recognized to promote crop growth and reduce the adverse effects of salt stress.In this study,key endophytic bacteria that can respond to salinity changes were identified by analyzing the microbial community in propagules of Kandelia obovata.Delftia tsuruhatensis DYX29,a strain that can grow normally under high salinity conditions with a sodium chloride(NaCl)concentration of 5%(w/v),was obtained by pure culture.DYX29 can produce siderophores with a siderophore unit value of 87.6%and 1-aminocyclopropane-1-carboxylate(ACC)deaminase with 29 UL^(-1),and its synthesis of intracellular amino acids and auxin can be induced by high salinity.Inoculation with DYX29 can remarkably promote the salt tolerance of rice.Under salt stress,the addition of DYX29 was shown to effectively promote the growth of rice seedlings through a variety of approaches.It increased the biomass of rice seedlings by 32.9%(dry weight)and promoted the accumulation of soluble sugars by 23.1%.It also increased catalase(CAT)and peroxidase(POD)activities in rice leaves by 37.8 and 88.2%,respectively.Moreover,it maintained the ionic homeostasis in rice roots and leaves.In addition,it upregulated the expression of growth-promoting hormones,such as indole-3-acetic acid(IAA),brassinolide(BL),abscisic acid(ABA),and salicylic acid(SA),in rice roots by 27.8,69.5,123.7 and 28.6%,respectively.This study provides inspiration for screening valuable salt-tolerant pro-biotic bacteria from mangrove ecosystems and their use for crop growth promotion under salt stress.It can also provide useful references for the development of new salt-tolerant and pro-biotic biofertilizers,as well as the investigation of the related mechanisms.
基金the National Natural Science Foundation of China(31870420)the Science and Technology Program of Guangdong Province,China(2121A0505030057)。
文摘Continuous cropping leads to high incidence of soilborne diseases such as bacterial wilt caused by Ralstonia solanacearum,which poses a risk to agricultural production.Anaerobic soil disinfestation(ASD)and plant growthpromoting rhizobacteria(PGPR)are considered environmentally friendly methods to control bacterial wilt.However,the underlying mechanism of the improvement of soil health and the inhibition of bacterial wilt after ASD treatment and PGPR inoculation needs further exploration.This study evaluated the effect of ASD treatment on soil improvement at pre-planting of tomato,and the effect of ASD treatment combined with the application of Bacillus velezensis Y6(BV)on soil quality,R.solanacearum abundance,and bacterial communities at 90 days before harvesting of tomato.The results showed that ASD treatment reduced R.solanacearum abundance in soil by17.6%at pre-planting and 18.7%at 90 days before harvesting,but BV inoculation did not influence R.solanacearum abundance.ASD and ASD+BV treatments effectively reduced the occurrence of bacterial wilt,improved soil nutrient status and increased soil microbial activity at 90 days before harvesting.Principal co-ordinate analysis showed that the soil bacterial community was significantly influenced by ASD treatment both at pre-planting and at 90 days before harvesting.Further investigation found that ASD contributed to the enrichment of beneficial flora(Bacillus and Streptomyces).Moreover,pH was an important environmental factor affecting the abundance of R.solanacearum in soil.Co-occurrence network analysis showed that ASD treatment significantly increased network connection of bacterial communities and the proportion of beneficial microorganisms(Proteobacteria and Firmicutes),leading to complex soil bacterial co-occurrence networks both at pre-planting and at 90 days before harvesting.Collectively,these results indicate that ASD treatment,but not microbial inoculation can enhance tomato plant resistance to bacterial wilt by improving soil quality and modulating the soil bacterial community.
基金supported by funding from the National Natural Science Foundation of China(32060593 and 32060474)the Yunnan Provincial Science and Technology Department+4 种基金China(202101AT070021 and 202101AS070001)the Yunnan Provincial Department of Education Science Research Fund ProjectChina(2023J0006)the Graduate Innovation Project of Yunnan UniversityChina(KC-22223012 and ZC-22222760)。
文摘Oryza longistaminata is an African wild rice species with valuable agronomic traits and the donor parent of perennial rice.Endophytic bacteria play an important role in host health,adaptive evolution and stress tolerance.However,endophytic bacterial communities in O.longistaminata and their plant growth-promoting(PGP)effects on the perennial rice of O.longistaminata offspring are poorly understood.In this study,the endophytic bacterial diversity,composition and network structures in the root,stem,and leaf tissues of O.longistaminata were characterized using Illumina sequencing of the 16S rRNA gene.The results suggested that O.longistaminata contains a multitude of niches for different endophytic bacteria,among which the root endosphere is more complex and functionally diverse than the stem and leaf endospheres.Tissue-specific biomarkers were identified,including Paludibaculum,Pseudactinotalea and Roseimarinus and others,for roots,Blautia for stems and Lachnospiraceae NK4A136 for leaves.The endophytic bacterial network of O.longistaminata was reassembled for various functions,including degradation/utilization/assimilation,detoxification,generation of precursor metabolites and energy,glycan pathways,macromolecule modification and metabolism.A total of 163 endophytic bacterial strains with PGP traits of potassium release,phosphate solubilization,nitrogen fixation,siderophore activity,indole-3-acetic acid(IAA)production,and 1-aminocyclopropane-1-carboxylate(ACC)deaminase activity were isolated from O.longistaminata.Eleven strains identified as Enterobacter cloacae,Enterobacter ludwigii,Stenotrophomonas maltophilia,Serratia fonticola,and Bacillus velezensis showed stable colonization abilities and PGP effects on perennial rice seedlings.Inoculated plants generally exhibited an enhanced root system and greater photosynthesis,biomass accumulation and nutrient uptake.Interestingly,two strains of E.cloacae have host genotype-dependent effects on perennial rice growth.The results of this study provide insights into the endophytic bacterial ecosystems of O.longistaminata,which can potentially be used as biofertilizers for sustainable perennial rice productivity.
基金funded by the National Natural Science Foundation of China (No. 42107513)the Key Projects of Natural Science Foundation of Gansu Province (No. 22JR5RA051)+1 种基金the Key Research and Development Program of Gansu Province (No. 21YF5FA151)the Gansu Province science and Technology project (21JR7RA070)
文摘Enhancing the growth of alfalfa(Medicago sativa L.)through inoculation with rhizobacteria represents a sustainable strategy for reclaiming saline soils.However,the lack of suitable strains and practical application guidelines poses significant challenges to the utilization of Plant Growth-Promoting Rhizobacteria(PGPR)in saltaffected soils of Northwest China.In this study,we selected four PGPR strains derived from indigenous halophytes based on their growth-promoting characteristics.These strains underwent further selection via a petri dish assay.Subsequently,the effects of the selected PGPR strains on alfalfa growth and soil fertility were rigorously examined through pot trials.The results demonstrated that Bacillus filamentosus HL3,B.filamentosus HL6,Bacillus subtilis subsp.stercoris HG12,and Paenibacillus peoriae HG24 significantly produced indole-3-acetic acid(IAA),solubilized phosphorus,and fixed nitrogen(except for B.filamentosus HL6,which did not significantly fix nitrogen).Compared to non-inoculated plants,B.filamentosus HL6 and B.subtilis subsp.stercoris HG12 significantly enhanced seed germination,root elongation,and seedling biomass in a 150 mmol/L NaCl saline solution.In saline-alkaline soils,PGPR inoculation under brackish water irrigation did not restore alfalfa growth to the levels observed under freshwater irrigation.Principal Component Analysis(PCA)condensed ten indicators into two indices,explaining 86.85%of the variance.Using these two indices as weights,an evaluation model for the PGPR-alfalfa symbiosis indicated that B.subtilis subsp.stercoris HG12 had the most substantial effect under freshwater irrigation,while co-inoculation with B.subtilis subsp.stercoris HG12 and B.filamentosus HL6 had the most significant impact on alfalfa growth and soil improvement under brackish water irrigation.Available phosphorus was identified as the primary factor influencing alfalfa growth,contributing 82.3%to the growth variation.These findings provide suitable microbial strains for the utilization of saline-alkali land and underscore the potential of applying indigenous PGPR-alfalfa symbiotic techniques to improve soil fertility and crop yield in the arid regions of Northwest China.
