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A lipopolysaccharide was isolated from cells of the type strain of a rhizobacterium Azospirillum agricola CC-HIH038 by phenol extraction. The O-specific polysaccharide was obtained by mild acid hydrolysis of the lipopolysaccharide followed by chromatographic fractionation. Monosaccharide analysis, including determination of absolute configurations and 1D and 2D 1H and 13C NMR spectroscopy, revealed the following structure of the O-specific polysaccharide repeating unit of A. agricola CC-HIH038T: →3)-α-L-Rhap2Ac-(1 → 3)-α-L-Rhap-(1 → 3)-α-L-Rhap-(1 → 3)-β-D-GlcpNAc6Ac-(1→. This unit is structurally related to that of A. doebereinerae GSF71T. Based on the analysis of full-genome sequencing data for strains A. agricola CC-HIH038T and A. doebereinerae GSF71T, the loci for O-specific polysaccharide biosynthesis have been identified. They were characterized by similar organization and a high level of gene homology, confirming the common structure of the O-antigens of these strains. [ABSTRACT FROM AUTHOR]

Developing microbial consortia emerges as a new research frontier since complementing metabolisms provides new biotechnological capabilities for symbiotic interaction. To date, microalgal consortia with other microorganisms, such as fungi, bacteria, or other microalga are considered a biotechnological strategy to enhance microalgal physiological performance during CO2 removal from biogas—a gaseous by-product composed mainly of methane (CH4, 65–70%) and CO2 (25–30%) considered an energy source due to its high methane content. Today, microalga-microorganism interaction studies have focused on developing diverse microbial consortia to increase CO2 fixation of biogas and their metabolic changes during processing time. Thus, the present review proposes in a novel way the use of microalgal growth-promoting bacteria (MGPB) as a suitable partner to boost microalgal physiological performance and positively influence CO2 fixation from biogas. Furthermore, the MGPB mechanisms involved during MGPB-microalga interaction to mitigate or regulate microalgae metabolism under the stressful condition of this gaseous effluent and improve their biotechnological uses focusing on CO2 removal from biogas are analyzed and proposed. Additionally, the microalgal ability to convert CO2 from biogas into high-value biotechnological compounds of commercial interest is analyzed, including the economic feasibility and scalability of a microalga-MGPB consortium. This physiological knowledge of microalga-MGPG consortia notably warrants its real impact on different economic sectors as a bio-economy overview. Furthermore, the discussion between engineering and biological sciences facilitates the development of suitable bioprocesses based on microalgae. [ABSTRACT FROM AUTHOR]

Water scarcity and global food requirements are two major issues currently that need to be dealt with as soon as possible. Aerobic rice, grown without submergence and requiring occasional irrigation, offers a sustainable solution to water scarcity, contributing to sustainable agriculture. In the present study, nine experimental treatments, consisting of application methods of gel-biofertilizers (seed treatment, soil treatment, and seed + soil treatment) and split application of potassium (at basal, 30DAS, and 50DAS), along with one control, were replicated thrice. Results revealed that application of gel-biofertilizers as seed and soil treatment along with 3 equal splits of potassium recorded significantly higher plant height (97.65 cm), dry weight (27.08 g), panicles/m² (267.20), grain yield (3.35 t/ha), and stover yield (7.47 t/ha). Maximum gross returns (1,80,311.47 INR/ha), net returns (1,10,126.61 INR/ha), and benefit:cost ratio (1.57) were also recorded with the same treatment. Hence it is concluded that application of gel-biofertilizers as seed and soil treatment along with 75% recommended dose of fertilizers with 3 split applications of potassium gives a higher benefit:cost ratio over control (100% RDF). [ABSTRACT FROM AUTHOR]

A whole genome sequence of a new strain of the nitrogen-fixing bacterium Azospirillum doebereinerae, known for its diverse plant growth-promoting bacteria (PGPB), was obtained for the first time. The strain, designated Azospirillum doebereinerae AT, was isolated during a soil analysis in the Chernevaya taiga of Western Siberia, a unique and fertile forest ecosystem known for its diverse plant growth-promoting bacteria (PGPB). The A. doebereinerae genome under study is fully assembled into seven circular molecules, none of which are unequivocally plasmids, with a total length of 6.94 Mb and a G + C content of 68.66%. A detailed phylogenomic analysis confirmed its placement within the genus Azospirillum, specifically closely related to A. doebereinerae GSF71T. Functional annotation revealed genes involved in nitrogen metabolism, highlighting the potential of strain TA as a biofertilizer and plant growth-promoting agent. The findings contribute to our understanding of the genomic diversity and metabolic potential of the Azospirillum genus, and they are of interest for further study in the field of comparative bacterial genomics, given the strain's multi-chromosomal genome structure. [ABSTRACT FROM AUTHOR]

A field experiment was conducted during rabi season (September to January) of 2021 and 2022 at the experimental farm of Integral Institute of Agricultural Science and Technology, Integral University, Lucknow, Uttar Pradesh, India. The objective of the experiment is to find out the most efficient combination of different organic and inorganic sources of nutrients to increase the growth, yield characteristics of cauliflower. Total nine numbers of treatments along with the control treatment were assessed in Randomized Block Design with three numbers of replications. In view of, effect of different organic and inorganic sources of nutrients has observed significant variation. The result revealed that the growth parameters like plant height (5.57, 12.47, 19.77 cm), number of leaves (7.97, 9.53, 13.7), length of leaves (17.30, 24.73, 31.73 cm), width of leaves (7.17, 10.20, 15.10 cm), plant spread (285.50, 806.93, 1212.83 cm) at 20, 40 and 60 days respectively, yield parameters like weight of curd (893.73 g), yield of curd plot-1 (13.40 kg), yield of curd ha-1 (25.30 t) were observed higher in 75% N through RDF+25% N through FYM+Azotobacter @ 5 kg ha-1 (T4). INM treatments showed lesser result on growth and yield of cauliflower in T1 (control). The treatment T4 were the most beneficial treatment which may be followed for commercial cauliflower cultivation on large scale. Thus, farmers are suggested to apply 75% N through RDF+25% N through FYM+Azotobacter @ 5 kg ha-1 to increase growth and yield of cauliflower. [ABSTRACT FROM AUTHOR]

A study was done during two consecutive seasons of 2022/2023 and 2023/2024 to study the effects of humic acid (HU 4, 8, and 12 kg/hectare) as the main plot and BM (Azotobacter chrococum, Azospirulm Brasiliense, and Bacillus polymaxa) and algae extracts (ALG) as the subplot as well as their interactions on plant growth. The design of the experiment was a split plot, including 16 treatments and three replicates. The results showed that the growth parameters, fruit yield measurement, and oil production were noticeably enhanced using humic acid and biostimulants (BM and ALG). In this concern, the high-rise values were obtained by utilizing the high level of HU (12 kg/hectare) with bio-fertilizer (BM + ALG) application compared with control during both seasons. Also, GCMS analysis of the volatile oil revealed that HU and a mixture of bacteria and algae extract had improved the primary volatile oil components of coriander (Linalool - α-Pinene - γ-Terpinene - P-Cymene - Geranial Acetate).

The article examines the effect of Azospirillum and Potash Solubilizing Bacteria (KSB) on the growth and yield of finger millet, also known as ragi, focusing on enhancing crop productivity through biofertilizers combined with chemical fertilizers. It highlights improvements in growth parameters like seed germination, plant height, number of tillers, finger length, and yield, demonstrating the efficacy of biofertilizers in improving soil fertility and reducing chemical fertilizer usage.

The diversity of phage-related sequences (PRSs) and their site-specific integration into the genomes of nonpathogenic, agriculturally valuable, nitrogen-fixing root nodule bacteria, such as Sinorhizobium meliloti, were evaluated in this study. A total of 314 PRSs, ranging in size from 3.24 kb to 88.98 kb, were identified in the genomes of 27 S. meliloti strains. The amount of genetic information foreign to S. meliloti accumulated in all identified PRSs was 6.30 Mb. However, more than 53% of this information was contained in prophages (Phs) and genomic islands (GIs) integrated into genes encoding tRNAs (tRNA genes) located on the chromosomes of the rhizobial strains studied. It was found that phiLM21-like Phs were predominantly abundant in the genomes of S. meliloti strains of distant geographical origin, whereas RR1-A- and 16-3-like Phs were much less common. In addition, GIs predominantly contained fragments of phages infecting bacteria of distant taxa, while rhizobiophage-like sequences were unique. A site-specific integration analysis revealed that not all tRNA genes in S. meliloti are integration sites, but among those in which integration occurred, there were "hot spots" of integration into which either Phs or GIs were predominantly inserted. For the first time, it is shown that at these integration "hot spots", not only is the homology of attP and attB strictly preserved, but integrases in PRSs similar to those of phages infecting the Proteobacteria genera Azospirillum or Pseudomonas are also present. The data presented greatly expand the understanding of the fate of phage-related sequences in host bacterial genomes and also raise new questions about the role of phages in bacterial–phage coevolution. [ABSTRACT FROM AUTHOR]

An open-field experiment was conducted in Cabuyao, Laguna, Philippines to investigate the effects of combining chemical fertilizers, vermicompost, arbuscular mycorrhizal fungi (AMF), and nitrogen-fixing bacteria (Azospirillum spp.) on the growth, nutrient uptake, and yield of tomato plants. The experiment was arranged in a randomized complete block design replicated four times. The treatments include the recommended rate of chemical fertilizer (RRC) and three integrated nutrient management (INM) strategies. The results revealed that AMF inoculation significantly increased the uptake of P, K, Ca, and Mg while INM 3 recorded the highest N uptake. Treatments with vermicompost application recorded a significantly higher uptake of Cu. INM 1, INM 2, and INM 3 gave a significantly higher fruit yield than the RRC with an increase of 8%, 13%, and 14%, respectively. The percentage of mycorrhizal root colonization and number of rhizosphere spores were higher in mycorrhizal plants. Fruit yield and AMF root colonization were positively correlated with the uptake of several nutrients. INM strategies obtained a higher net income than the current fertilizer recommendation by 4–15%. These findings imply that the INM strategies can increase tomato productivity, reduce the amount of chemical fertilizer inputs, increase profitability, and potentially lead to soil health and environmental benefits. [ABSTRACT FROM AUTHOR]

The growth and productivity of wheat is mainly dependent on the availability of major essential plant nutrients. Of the major essential nutrients, nitrogen occupies a prime place and plays an important role in plant metabolism ultimately reflecting on crop production. In view of increasing cost and scarcity of nitrogenous fertilizers, exploring alternative approaches to supply crucial essential nutrients has become imperative. The use of plant growth-promoting rhizobacteria (PGPR), capable of performing biological nitorgen fixation and growth hormone production enhances growth and improves quality. Among PGPR members, genus Azospirillum are well known and commonly used bacteria in agriculture. A total of four native selected Azospirillum isolates viz., UASDAZO-13, UASDAZO-21, UASDAZO-29 and UASDAZO-46 along with reference strain (ACD-15) were inoculated and evaluated on wheat growth at different nitrogen levels. Inoculation of efficient Azospirillum isolates along with a reference strain on wheat significantly increased seed germination, plant height, number of tillers and root parameters like root diameter, volume and surface area over uninoculated control (UIC). It was found that superior growth was observed in UASDAZO-29 inoculated with 75 per cent N application as per RDF. [ABSTRACT FROM AUTHOR]

A study was done during two consecutive seasons of 2022/2023 and 2023/2024 to study the effects of humic acid (HU 4, 8, and 12 kg/hectare) as the main plot and BM (Azotobacter chrococum, Azospirulm Brasiliense, and Bacillus polymaxa) and algae extracts (ALG) as the subplot as well as their interactions on plant growth. The design of the experiment was a split plot, including 16 treatments and three replicates. The results showed that the growth parameters, fruit yield measurement, and oil production were noticeably enhanced using humic acid and biostimulants (BM and ALG). In this concern, the high-rise values were obtained by utilizing the high level of HU (12 kg/hectare) with bio-fertilizer (BM + ALG) application compared with control during both seasons. Also, GCMS analysis of the volatile oil revealed that HU and a mixture of bacteria and algae extract had improved the primary volatile oil components of coriander (Linalool - α-Pinene - γ-Terpinene - P-Cymene - Geranial Acetate). [ABSTRACT FROM AUTHOR]

Seven auxin-producing endophytic bacterial strains (Azospirillum spp., Methylobacterium symbioticum, Bacillus spp.), and two different combinations of these strains were used to verify their influence on tomato during germination and development in hydroponic conditions where, as a novelty for Canestrino di Lucca cultivar, endophytic bacteria were inoculated. To emphasize the presence of bacterial auxins in roots and stems of seedlings, both in situ staining qualitative assessment and quantitative analysis were carried out. Moreover, hypogeal and epigeal growth of the plantlets were measured, and correlation analyses were conducted to examine the relationship between the amount of indolacetic acid (IAA) produced by the bacterial strains and root and stem parameters. Plantlets treated with microbial inoculants showed a significant increase in the survival rate compared to the control treatment. The best results as IAA producers were from Azospirillum baldaniorum Sp245 and A. brasilense Cd, which also induced significant root growth. On the other hand, Bacillus amyloliquefaciens and B. licheniformis induced the best rates in stem growth. These findings highlight the potential for using endophytic bacterial strains in a hydroponic co-cultivation system that enables inoculating plantlets, at an early stage of growth (5 days old). [ABSTRACT FROM AUTHOR]

Nitrogen is the most common limiting factor for crop productivity, and most maize cultivars require fertilizing. Here, we report on the possibility of partially replacing the nitrogenous fertilizer in sweet corn inoculated with a native strain of Azospirillum sp. in arid land on the coast of Peru. We performed an agronomic experiment in a crop field with arid soil under drip irrigation in Huacho (Peru) using a commercial variety of sweet corn. The treatments were two levels of nitrogen (90 and 180 kg N ha−1), one or two applications of a native strain of Azospirillum sp. (1 × 108 CFU/mL) and a control treatment with only nitrogen fertilizer. Eleven agronomic variables related to productive aspects were evaluated by performing statistical analyses and the comparison of treatment means. Inoculation with Azospirillum sp. did not significantly (p > 0.05) affect the total weight of ears, the number of ears per plant and the number of male flowers, but it significantly (p < 0.05) influenced the grain yield per hectare, the survival of plants, grain weight per plant, and the diameter and length of the cob. In some productive characteristics of sweet corn cv "Pardo", a significant effect was found following inoculation with Azospirillum sp., which outperformed the control with only nitrogen fertilization in grain yield, suggesting that it is possible to complement the application of nitrogen to soil with the inoculation of this strain, replacing up to 50% of the levels of fertilizer application, since the benefit/cost ratio increases. [ABSTRACT FROM AUTHOR]

This work aimed to assess Rhizobium tropici, Azospirillum brasilense, and Trichoderma asperellum co-inoculation effects, besides N-fertilizer supplementation as determined by the nitrogen sufficiency index (NSI) on the development of common bean. Field trials were carried out in a randomized block design with four replicates at three different locations. Treatments consisted of sole or combined inoculation of R. tropici, A. brasilense, and T. asperellum, besides N-fertilization. Seeds were inoculated with R. tropici and/or T. asperellum using 10 g of each inoculant kg−1 of seed. At the phenological stage V2/V3 A. brasilense was inoculated using 300 ml ha−1. Nitrogen sufficiency index (NSI), number of nodules (NN), nodule dry mass (NDM), root dry mass (RDM), shoot dry mass (SDM), number of pods (NP), number of grains (NG), and grain yield (GY) were assessed. NN and NDM were higher under R. tropici, A. brasilense, and T. asperellum co-inoculation. This same co-inoculation provided RDM and SDM similar to the use of 120 kg ha−1 of N. R. tropici, A. brasilense, and T. asperellum co-inoculation supplemented with N-fertilizer at the phenological stage R5, provide NP and NG similar to 120 kg ha−1 N, and to 80 kg ha−1 N supplemented with N at the phenological stage V4. NSI was effective to determine the N needs of common bean. The co-inoculation of two doses ha−1 of R. tropici, three doses ha−1 of A. brasilense and two doses ha−1 of T. asperellum, supplemented with N-fertilizer at phenological stage V4 based on NSI, stimulated growth and yield components of common bean, providing GY equivalent to the N-fertilized treatments. [ABSTRACT FROM AUTHOR]

The article explores the possibility of identifying Napoleon's skin disease and treatment through paleoproteomic analyses of his last bathtub in 1821. Residual deposits in the bathtub were analyzed for toxicological and elemental dosages, revealing high concentrations of sulphur and arsenic, potentially indicating the use of seawater with added arsenic for dermatological treatment. The study also detected various taxa, including human proteins, bacteria, and fungi, suggesting the use of seawater and other medicinal materials in Napoleon's therapeutic bathing practices. The presence of Bacillus idriensis raises questions about potential skin infections that may have affected Napoleon at the time of his death. [Extracted from the article]

Nitrogen is the most common limiting factor for crop productivity, and most maize cultivars require fertilizing. Here, we report on the possibility of partially replacing the nitrogenous fertilizer in sweet corn inoculated with a native strain of Azospirillum sp. in arid land on the coast of Peru. We performed an agronomic experiment in a crop field with arid soil under drip irrigation in Huacho (Peru) using a commercial variety of sweet corn. The treatments were two levels of nitrogen (90 and 180 kg N ha−1), one or two applications of a native strain of Azospirillum sp. (1 × 108 CFU/mL) and a control treatment with only nitrogen fertilizer. Eleven agronomic variables related to productive aspects were evaluated by performing statistical analyses and the comparison of treatment means. Inoculation with Azospirillum sp. did not significantly (p > 0.05) affect the total weight of ears, the number of ears per plant and the number of male flowers, but it significantly (p < 0.05) influenced the grain yield per hectare, the survival of plants, grain weight per plant, and the diameter and length of the cob. In some productive characteristics of sweet corn cv “Pardo”, a significant effect was found following inoculation with Azospirillum sp., which outperformed the control with only nitrogen fertilization in grain yield, suggesting that it is possible to complement the application of nitrogen to soil with the inoculation of this strain, replacing up to 50% of the levels of fertilizer application, since the benefit/cost ratio increases.

A factorial experiment was conducted at the Research Station of the College of Agriculture, Anbar University, using the RCBD factorial experiments to determine the effect of the type of carrier and bacterial inoculum on the growth and yield of potatoes. Three carrier materials were used: pre-ripened date seeds, molasses, and zeolite as a control. B. megaterium and A. lipoferum carriers and inoculum were prepared and incubated for five days. The treatments were distributed randomly, adding the full fertilizer recommendation to the field, except P and N, which were added at a rate of 60% of the recommendation. The results showed that the carrier made from pre-ripe date seeds was superior to the zeolite, as the highest plant height and potato yield were recorded at 73.22 cm and 42.95 tons ha-1, with a significant difference from the lowest rate recorded for zeolite, 67.17 cm and 38.18 tons ha-1, respectively. Dpbm and molasses carriers recorded the highest percentages of N and P in soil, reaching 47.0, 45.98, 11.77, and 11.18 mg kg-1 soil, respectively. B. megaterium recorded the highest yields of potato and phosphorus in the soil, reaching 44 ton ha-1 and 9.86 mg Pkg-1. The interaction DpbB-B. megaterium recorded the highest average soil microbial content at 8.65 log cfu g-1. The molasses-A followed the lipoferum interaction with an average microbial content of 6.831 and 6.35.65 log cfu g-1.

BACKGROUND: The plant growth‐promoting bacteria (PGPB) Azospirillum brasilense is widely used as an inoculant for important grass crops, providing numerous benefits to the plants. However, one limitation to develop viable commercial inoculants is the control of PGPB survival, requiring strategies that guarantee their survival during handling and field application. The application of sublethal stress appears to be a promising strategy to increase bacterial cells tolerance to adverse environmental conditions since previous stress induces the activation of physiological protection in bacterial cell. In this work, we evaluated the effects of thermal and salt stresses on the survival of inoculant containing A. brasilense Ab‐V5 and Ab‐V6 strains and we monitored A. brasilense viability in inoculated maize roots after stress treatment of inoculant. RESULTS: Thermal stress application (> 35 °C) in isolated cultures for both strains, as well as salt stress [sodium chloride (NaCl) concentrations > 0.3 mol L−1], resulted in growth rate decline. The A. brasilense enumeration in maize roots obtained by propidium monoazide quantitative polymerase chain reaction (PMA‐qPCR), for inoculated maize seedlings grown in vitro for 7 days, showed that there is an increased number of viable cells after the salt stress treatment, indicating that A. brasilense Ab‐V5 and Ab‐V6 strains are able to adapt to salt stress (0.3 mol L−1 NaCl) growth conditions. CONCLUSION: Azospirillum brasilense Ab‐V5 and Ab‐V6 strains had potential for osmoadaptation and salt stress, resulting in increased cell survival after inoculation in maize plants. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The use of plant symbiosis with arbuscular mycorrhizal fungi (AMF) and Plant-growth-promoting rhizobacteria (PGPR) is one of the ways to reduce drought stress that has recently been used in agriculture. For this purpose, the present study was conducted was conducted to evaluate the effects of the application of PGPR and AMF on the quantitative and qualitative characteristics of lemon balm (Melissa officinalis L.) under drought stress. The experiment was carried out as a factorial in a completely randomized design with five replications in the greenhouse of Islamic Azad University, Ayatollah Amoli Branch, Amol, Iran, in 2020. Drought stress at two levels (control or 100% field capacity and 50% field capacity) as the first factor and seed inoculation with symbiosis microorganisms at four levels (no inoculation, inoculation with Azospirillum brasilense strain Sp245 (108 CFU/mL), inoculation with Glomus mosseae (100 g per pot) and inoculation with A. brasilense + G. mosseae) were considered as the second factor. The results of the present study showed that drought stress by reducing the relative water content (RWC, 17.8%), declined transpiration rate (E, 62.2%), stomatal conductance (gs, 36.8%), intercellular CO2 concentration (Ci, 22.5%), and net photosynthesis (Pn, 48.5%) of the plant compared to control plants. Drought stress also induced oxidative stress by increasing the accumulation of hydrogen peroxide (2.1-fold) and methylglyoxal (2-fold), resulting in damage to bio-membranes and photosynthetic apparatus and reduced growth of lemon balm. However, microbial inoculation, especially co-inoculation of PGPR and AMF, by improving the proline content and RWC, restored Ci, E, gs and Pn under drought stress. Microbial treatments by increasing the activity of antioxidant enzymes and the glyoxalase system reduced the level of hydrogen peroxide and methylglyoxal and alleviated drought stress-induced oxidative stress, which increased the growth of lemon balm under drought stress by protecting bio-membranes and photosynthetic pigments. The results showed that the application of G. mosseae and A. brasilense alleviated the negative effects of drought stress on lemon balm. [ABSTRACT FROM AUTHOR]

Root research often uses rhizotron systems where their main characteristic is to possess a transparent wall allowing the in situ observation of plants' root system. Rhizotrons can vary in size and be filled with different substrates based on soil, sand and other components. Here, a simple and low cost rhizotron system without soil substrate was developed, allowing the observation of wheat (Triticum aestivum L.) root system treated with bioproducts. To show the effectiveness of the rhizotrons, hydrated wheat seeds were treated with plant growthpromoting bioproducts such as Azospirillum argentinense REC3 (106 CFU.ml-1), flagellin AzFlap (200 nM), or strawberry hydroalcoholic extract (0.01 mg.mL-1). This rhizotron system allowed to non-destructively evaluate the roots (length, density and root hair proliferation), where the values of the bioproducts surpassed the control. [ABSTRACT FROM AUTHOR]

Motile plant-associated bacteria use chemotaxis and dedicated chemoreceptors to navigate gradients in their surroundings and to colonize host plant surfaces. Here, we characterize a chemoreceptor that we named Tlp2 in the soil alphaproteobacterium Azospirillum brasilense. We show that the Tlp2 ligand-binding domain is related to the 4-helix bundle family and is conserved in chemoreceptors found in the genomes of many soil- and sediment-dwelling alphaproteobacteria. The promoter of tlp2 is regulated in an NtrC- and RpoN-dependent manner and is most upregulated under conditions of nitrogen fixation or in the presence of nitrate. Using fluorescently tagged Tlp2 (Tlp2-YFP), we show that this chemoreceptor is present in low abundance in chemotaxis-signaling clusters and is prone to degradation. We also obtained evidence that the presence of ammonium rapidly disrupts Tlp2-YFP localization. Behavioral experiments using a strain lacking Tlp2 and variants of Tlp2 lacking conserved arginine residues suggest that Tlp2 mediates chemotaxis in gradients of nitrate and nitrite, with the R159 residue being essential for Tlp2 function. We also provide evidence that Tlp2 is essential for root surface colonization of some plants (teff, red clover, and cowpea) but not others (wheat, sorghum, alfalfa, and pea). These results highlight the selective role of nitrate sensing and chemotaxis in plant root surface colonization and illustrate the relative contribution of chemoreceptors to chemotaxis and root surface colonization. [ABSTRACT FROM AUTHOR]

Copyright of Anbar Journal of Agricultural Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Colombiana de Ciencias Hortícolas is the property of Revista Colombiana de Ciencias Horticolas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The grain production area in the Brazilian agricultural region known as SEALBA, especially in Alagoas State, has seen significant growth in recent years. This study aims to contribute to sustainable regional development by evaluating the effects of inoculation, co-inoculation, and the application of starter mineral nitrogen (N), either individually or in combination, on soybean growth and yield. Eight field experiments were conducted from 2018 to 2021 in two municipalities within Alagoas, covering soybean cultivation areas ranging from the first to the fourth year. The experiments followed a randomized complete block design with four replications, employing a factorial arrangement of treatments. The first factor encompassed five levels related to inoculation technologies and N management: 1) Inoculation with Bradyrhizobium; 2) Inoculation with Bradyrhizobium combined with N basal fertilization; 3) Co-inoculation of Bradyrhizobium + Azospirillum; 4) Co-inoculation of Bradyrhizobium + Azospirillum + N fertilization at the base; and 5) Control treatment without microbiological inputs or nitrogen fertilizers. The second factor involved the evaluation of different soybean cultivars, with two materials assessed in 2018 and three cultivars in 2019, 2020, and 2021. Results demonstrated that seed inoculation with Bradyrhizobium led to increased soybean grain yield in first-year cultivation areas. However, N basal fertilization, commonly known as starter fertilization, did not result in yield improvements compared to the use of microbiological inputs alone. Soybean cultivars BRS 9383 IPRO and FTR 3191 IPRO exhibited greater responsiveness to seed inoculation with Bradyrhizobium.

Synthetic dyes are widely used in various branches of light industry. Due to the insuffi cient effi ciency of industrial painting processes, a large percentage of dyes end up in the wastewater of enterprises in an unmodifi ed form, which creates a huge risk of environmental pollution with these compounds. Triphenylmethane dyes, in particular malachite green, are toxic, allergenic and carcinogenic compounds. To date, biodegradability of triphenylmethane dyes has been shown for some bacteria and fungi producing phenol oxidase complex enzymes, including soil associative bacteria of the genus Azospirillum. Many factors are capable of inducing and inhibiting the biodegradation effi ciency, in particular the enzymatic systems that are involved in bleaching processes. In the present work we studied the eff ects of typical deactivating agents of phenol oxidases, such as H2 O2 , EDTA, SDS-Na, β-mercaptoethanol, dithiothreitol, Tween, and sodium azide, on the azospirilla’s phenol oxidases activity and the ability to decolorize malachite green. It was found that Tween and sodium azide do not have an inhibitory eff ect on azospirillum enzymes and exhibit a total stabilizing eff ect on the entire complex. An inhibitory eff ect from 60 to 100% was noted for laccase and Mn-peroxidase activity under the action of β-mercaptoethanol, dithiothreitol and EDTA, which is directly proportional to the decolorization rate of malachite green. Compared with the latest issues on classical phenol-oxidizing enzymes, our data revealed non-typical properties of the phenol oxidase complex enzymes of azospirillum.

The use of chemical inputs has led to the loss of microbial diversity involved in the N cycle, such as diazotrophic bacteria, which are inhibited by saturation of the receptors responsible for activating nitrogenase. Biological nitrogen fixation (BNF) in forage grasses can be used as an ecosystem service. The aim of this review was to analyze the contribution of forage grasses to BNF and their response to inoculation of non-symbiotic diazotrophs in order to find study opportunities. The analysis of the information was carried out using the prisma methodology of systematic reviews and meta-analyses. It should be noted that the main forage species that contribute to BNF are Brachiaria sp. and Pennisetum sp. The inoculation of Azospirillum sp. has generated a growth-promoting effect in grasses, but the response of the inoculated forage depends mainly on the synergy between plant and bacteria, showing neutral, antagonistic, and positive effects. [ABSTRACT FROM AUTHOR]

A fixação biológica de nitrogênio, promovida por bactérias do gênero Bradyrhizobium, além de substituir a adubação mineral, fornece nitrogênio suficiente para propiciar elevados rendimentos na cultura da soja. O objetivo do trabalho foi comparar a inoculação padrão de produto contendo Bradyrhizobium spp., aplicado isolado ou em associação com Azospirillum brasilense, com a pré-inoculação, via tratamento de sementes, na nodulação das plantas e produtividade de grãos da cultura da soja. O experimento foi implantado no mês de novembro de 2020 em quatro localidades (Mandaguaçu/PR, Marialva/PR, Paranavaí/PR e Itaquiraí/MS) com características edafoclimáticas distintas. Foi utilizado o delineamento em blocos casualizados, com sete tratamentos e cinco repetições. As variáveis avaliadas foram o número e massa seca de nódulos no início do florescimento, biomassa seca da parte aérea, teor de N e N-total na parte aérea e nos grãos e rendimento de grãos. Os resultados obtidos nos quatro ensaios permitiram concluir que a inoculação com Bradyrhizobium spp. + Azospirillum brasilense, via tratamento de sementes ou pulverização foliar do Azospirillum, mostrou-se tecnicamente viável na cultura da soja. [ABSTRACT FROM AUTHOR]

Plant growth-promoting bacteria (PGPB) that inhabit root rhizosphere of plants are of great agricultural importance due to their ability to produce phytohormones during root colonization. These phytohormones produce physiological changes in the plant that favor a greater absorption of nutrients, promote growth and increase production. This study analyzed the effect of inoculation of two of these bacteria, Azospirillum sp. and Pseudomonas fluorescens, under field conditions representative of the Andean Highlands. The experiment was carried out using flour corn seed of the INIAP-101 variety in a randomized complete block design with six repetitions. The treatments corresponded to: T1 (Azospirillum sp.), T2 (P. fluorescens), T3 (Azospirillum sp. and P. fluorescens), T4 (control, conventional chemical fertilization) and T5 (absolute control). The application of these bacteria significantly increased (p<0.05) the root length, the diameter of the cob, and the yield of fresh corn ("elotes" or "choclos"). The combined inoculation of these bacteria (T3) obtained the highest yield, with 19.70 t ha􀀀1 of fresh corn; while the chemical control and the absolute control got 17.12 and 13.58 t ha􀀀1 of fresh corn, respectively. The economic analysis of T3 reported a benefit/cost of 1.35, which indicates that the synergism of these two bacteria could be a sustainable strategy to improve yields and reduce the use of chemical fertilizers for corn production in the Andean region. [ABSTRACT FROM AUTHOR]

Due to the effect of herbicide on the soil, the natural fluorescence changes, and prevents the growth of bacteria that fix nitrogen an imbalance occurs between the organisms that live in the soil. Harmful organisms present in the soil increase until they become pests. Studying the effects of glyphosate on nitrogen-fixing bacteria like Azospirillum normally includes a combination of laboratory and field trials. An overarching framework for conducting such studies is outlined below. The average number of Azospirillum cells at each concentration and in the control group is shown by the mean values. There were more total counts of Azospirillum in the control group, suggesting a higher mean (8200.00) without glyphosate. There appears to be a dose-dependent effect of glyphosate on Azospirillum count, with the mean values decreasing as the concentration of glyphosate rises from 5% to 20%. The p-values give us an idea of how significant the results are. A p-value of 0.00001 for the 5% concentration level implies an extremely low likelihood of achieving the observed results if there were no meaningful effects. Work on the research began on 12/26/2022 in the laboratories affiliated with the College of Education for Pure Sciences, University of Mosul, and the work and writing of the research was completed within 7 months. [ABSTRACT FROM AUTHOR]

The dose-dependent effect of the A.brasilense Sp7 lectin on the roots of 4-day-old wheat seedlings (Triticumaestivum L. cv. Saratovskaya 29) grown under simulated salt stress was studied. In the roots of wheat seedlings under salt stress, lectin increased the activity of peroxidase and superoxide dismutase, but decreased the activity of catalase. In the roots of stressed seedlings, lectin reduced the total protein content and lipid peroxidation causing membrane damage, but increased the content of secondary metabolites, such as the total amount of phenols and flavonoids. It was concluded that Azospirillum lectins are involved in adaptive changes in the roots of wheat seedlings, due to which the relationship between bacteria and their hosts can be regulated when soil and climatic factors change. [ABSTRACT FROM AUTHOR]

A significant part of research in environmentally friendly agroindustrial production is aimed at immobilized bacterial preparations with retained capacity for active growth without loss of metabolic activity both during immobilization and after long-term storage and biotechnological use. In the present work, immobilization of members of the genus Azospirillum on natural and synthetic carriers was investigated. Efficiency of immobilization of the cells of A. brasilense strain SR80 in alginate hydrogel and vermiculite was investigated. Proliferative and metabolic activities of immobilized preparations were investigated. The prospects of using vermiculite and calcium alginate as matrices for Azospirillum immobilization are shown. [ABSTRACT FROM AUTHOR]

سابقه و هدف: با توجه به نیاز بالای کشور ایران به چای و کافی نبودن مقدار تولید داخلی، استفاده از کودهای شیمیایی جهت افزایش تولید در واحد سطح رو به افزایش است. کاربرد طولانی مدت کودهای شیمیایی به ویژه کودهای نیتروژن‌دار، سبب اسیدی شدن خاک باغ‌های چای شده و سلامت و کیفیت خاک را تحت تاثیر قرار داده است. از این رو، جست‌وجو برای یک روش جایگزین و کارآمد که کارایی آن به اندازه کودهای شیمیایی باشد و ضررهای ناشی از مصرف بی‌رویه کودهای شیمیایی را جبران نماید، ضروری است. مواد و روش‌ها: در این پژوهش ابتدا ریزوباکتری‌های بومی تثبیت کننده نیتروژن (آزوسپیریلیوم) و حل کننده فسفر از ریزوسفر گیاه چای جداسازی و سپس به عنوان کود زیستی در کشت گلدانی نهال‌های چای هیبرید چینی در پژوهشکده چای کشور در سال 1400 مورد استفاده قرار گرفتند. این آزمایش در قالب طرح بلوک کامل تصادفی با آرایش فاکتوریل در سه تکرار اجرا شد. فاکتورهای آزمایش شامل pH خاک در دو سطح (65/4 و 21/5) و تیمارهای کودی در پنج سطح شامل شاهد منفی (B)، کود شیمیایی بر اساس آزمون خاک (C)، کود زیستی باکتری تثبیت کننده نیتروژن (BN)، کود زیستی باکتری حل کننده فسفر (BP) و کود زیستی دارای باکتری‌های تثبیت کننده نیتروژن و حل کننده فسفر (BNP) بودند. پس از گذشت سه ماه از کشت نهال چای در گلدان-ها پیامد استفاده از این کودهای زیستی بر ویژگی‌های خاک و رشد گیاه چای مورد بررسی قرار گرفت. یافته‌ها:‌ مقدار pH خاک در تمامی تیمارهایی که کود زیستی دریافت نمودند نسبت به تیمارهای شاهد و کود شیمیایی بیشتر بود. بیشترین و کمترین مقدار نیتروژن خاک به ترتیب در تیمارهای BNP وB مشاهده شد. بیشترین مقدار فسفر فراهم خاک در تیمار BNP مشاهده شد که البته اختلاف معنی‌داری با تیمار و BN نداشت. مقدار پتاسیم قابل جذب خاک در تیمارهای دریافت کننده کود زیستی و شیمیایی اختلاف آماری معنی‌داری را نشان نداد. بیشترین و کمترین مقدار وزن تر، وزن خشک و محصول به ترتیب در تیمارهای BNP و B مشاهده شد. بیشترین محتوای نیتروژن و فسفر گیاه به ترتیب مربوط به تیمارهای BNP (8/4 درصد) و BP (24/0 درصد) بود. محتوای پتاسیم گیاه در تیمارهای کود زیستی بیشتر از تیمار شاهد بود، اگرچه درصد پتاسیم در تمامی تیمارهای کود زیستی از تیمار کود شیمیایی کمتر بود. نتیجه‌گیری: در این پژوهش، تیمار کودهای زیستی باکتری آزوسپیریلیوم و حل کننده فسفر به ترتیب سبب افزایش محتوای نیتروژن و فسفر گیاه چای و خاک زیرکشت آن شدند و کاربرد هم‌زمان آن‌ها سبب افزایش کارایی هردو شد. بنابراین، از آن‌جا که این باکتری‌ها سبب بهبود رشد گیاه و ویژگیهای خاک شدند به نظر می‌رسد رایزوباکترهای بومی جداشده از ریزوسفر چای پتانسیل استفاده در باغ‌های چای به عنوان کود زیستی را در راستای کشاورزی پایدار داشته باشند. اگرچه بررسی طولانی‌مدت در شرایط مزرعه طی چند دوره‌ی رشد و همچنین فصول مختلف سال برای ارزیابی‌های بیشتر مورد نیاز است.

IntroductionSouth of Iran has been located in the dry belt and desert strip thus water stress has always been one of the serious problems in its agriculture (Buzarjomehri et al., 2020). Intercropping is the cultivation of two or more plant species in a specific land and growing season, which is important in agricultural systems with limited resources and low input (Brooker et al., 2015). Due to the differences in the rooting depth, lateral expansion, and root density of cereals and legumes, they have been the best candidates for intercropping traditionally for limited soil water and nutrient availability environments (Babalola, 1980; Haynes, 1980). Application of bio-fertilizers (PGPR bacteria) that have nitrogen (N) fixation and phosphorus (P) solubilizing activity (Azospirillum brasilense and Pseudomonas fluorescence, respectively) is a promising approach for obtaining N, P, and water-restricted areas (Tien et al, 1979; Barea, 2015). Organic manures enhance soil water holding capacity and serve as excellent slow-release sources of nitrogen (N) and phosphorus (P) in the soil (Risse et al., 2006). This study aimed to investigate the effect of different fertilizer systems (chemical, integrated, and bio-organic) on triticale grain yield and its components in sole and intercropped triticale in triticale/chickpea system under late season water stress in a hot and dry area of southern Iran (Fars province - Darab). Materials and MethodsTo evaluate the yield and yield components of triticale (× Triticosecale Wittmack) in monoculture and intercropping with chickpea (Cicer arietinum L.) under late season water stress conditions, a split-factorial experiment in a randomized complete block design with three replications was implemented at the research field of the College of Agriculture and Natural Resources of Darab - Shiraz University in 2019-2020 growing season. Treatments were two levels of irrigation (Ir): [1- normal (IRN): irrigation based on the plant water requirement up to the physiological maturity stage (ZGS92) and 2- water stress (WS): irrigation based on the plant water requirement up to the milking stage] as the main plots and three fertilizer sources (FS) [1- chemical: ( 50 kg P ha-1 + 150 kg N ha-1), 2- integrated: (25 kg P ha-1 + 75 kg N ha-1 + 20 tons sheep manure ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilense) 3- bio-organic: 40 tons sheep manure ha-1 + inoculation with Pseudomonas fluorescens and Azospirillum brasilense] and two cropping systems (Cs) [1- monoculture of triticale, 2- intercropped triticale with chickpea (1:1)] as the sub-plots. Triticale grain yield and its components were measured and the harvest index (%) was calculated. Data were analyzed using SAS 9.1 software and the means were separated by the least significant difference (LSD) test at 5% probability level.Results and DiscussionThe results demonstrated that water stress reduced the grain yield and its components in triticale, with the extent of reduction varying among different treatments. In the Ir × Cs interaction, the Ws treatment reduced the triticale grain yield as compared to IRN by 38% and 55 % in the intercropped and sole-triticale, respectively. The Ir × Fs interaction showed that the grain yield decreased by water stress as a function of the fertilizer system (60.4%, 43.7%, and 30.7% reduction in the chemical, integrated, and bio-organic treatments, respectively). Evaluation of the results related to the triticale yield components (grain weight, biological yield, and harvest index) also showed that the Ws treatment reduced these traits. However, the least reduction occurred in bio-organic fertilizer as compared with the other fertilizer systems (significant Ir × Fs interaction). Furthermore, the Ir × Cs interaction showed that the Ws treatment reduced triticale grain weight and its biological yield as compared to IRN in both cropping systems with different manners. The least reduction of their traits by Ws treatment was showed in intercropped triticale as compared to its sole cropping.ConclusionBased on the results of this study, intercropped triticale with chickpea and using of bio-organic fertilizer were recommended for hot and dry areas of southern Iran where water stress may occur at the end of the growing seasons. Using these strategies leads to water stress alleviation and therefore less reduction of triticale grain yield in these environments.

An open-field experiment was conducted in Cabuyao, Laguna, Philippines to investigate the effects of combining chemical fertilizers, vermicompost, arbuscular mycorrhizal fungi (AMF), and nitrogen-fixing bacteria (Azospirillum spp.) on the growth, nutrient uptake, and yield of tomato plants. The experiment was arranged in a randomized complete block design replicated four times. The treatments include the recommended rate of chemical fertilizer (RRC) and three integrated nutrient management (INM) strategies. The results revealed that AMF inoculation significantly increased the uptake of P, K, Ca, and Mg while INM 3 recorded the highest N uptake. Treatments with vermicompost application recorded a significantly higher uptake of Cu. INM 1, INM 2, and INM 3 gave a significantly higher fruit yield than the RRC with an increase of 8%, 13%, and 14%, respectively. The percentage of mycorrhizal root colonization and number of rhizosphere spores were higher in mycorrhizal plants. Fruit yield and AMF root colonization were positively correlated with the uptake of several nutrients. INM strategies obtained a higher net income than the current fertilizer recommendation by 4–15%. These findings imply that the INM strategies can increase tomato productivity, reduce the amount of chemical fertilizer inputs, increase profitability, and potentially lead to soil health and environmental benefits.

Background and Objectives: Considering the high demand for tea in Iran and the insufficient local production, the use of chemical fertilizers to enhance production per unit area is increasing. The long-term use of chemical fertilizers, especially nitrogen fertilizers, in tea gardens has led to soil acidification which in turn impacted the soil quality and health. Therefore, searching for an alternative method that is as efficient as chemical fertilizers and compensates for the disadvantages caused by the excessive use of chemical fertilizers is essential in tea gardens nutrition. Materials and Methods: In this research, native nitrogen-fixing (Azospirillum) and phosphorus solubilizing rhizobacteria were isolated from the rhizosphere of tea plants and then used as biofertilizers for cultivation of Chinese hybrid tea seedlings at tea research center in 1400 under pot experiment. This experiment was conducted in a randomized complete block design with factorial arrangement and three replications. The factors include pH of soil at two levels (4.65 and 5.21), and fertilizer treatments at five levels including blank (B), control; where chemical fertilizer was applied based on soil analysis (C), nitrogen fixing bacteria was applied as biofertilizer (BN), phosphorus solubilizing bacteria was applied as biofertilizer (BP), and nitrogen fixing and phosphorus solubilizing bacteria were applied as biofertilizer (BNP). After three months of tea planting, the effect of applied biofertilizers on soil biochemical characteristics and yield of tea plant were investigated. Results: The soil pH values in all treatments that received biofertilizers were higher than that of the blank and control treatments. The highest and the lowest soil nitrogen (N) content were observed in BNP and B treatments, respectively. The highest content of soil phosphorus (P) was observed in BNP treatments, which P content in this treatment with BN was not significantly different. The soil available potassium content in treatments that receiving bio and chemical fertilizers did not show a statistically significant difference. The highest and the lowest values of fresh weight, dry weight and yield were observed in BNP and B treatments, respectively. The highest content of N and P in plant were observed in BNP (4.8%) and BP (0.24%) treatments, respectively. The potassium content of plant in treatments that received biofertilizers was lower than B, while the potassium content in all biofertilizer treatments were higher than that of the control. Conclusion: In this study biofertilizer treatments, Azospirillum and phosphorus solubilizing bacteria, increased the nitrogen and phosphorus contents in tea plant and soil, respectively. Since these bacteria improved plant growth and soil properties, it seems that native rhizobacteria isolated from tea rhizosphere have the potential to be used as biofertilizers in tea gardens in line with sustainable agriculture. Although, long term investigation during the several growth periods and different seasons of the year is needed for further evaluations. [ABSTRACT FROM AUTHOR]

Plant nutrition is one of the most important environmental factors affecting the quantitative and qualitative yield of crops. This study investigated the effect of rhizobium and azospirillum inoculum and foliar application of humic acid and nutrients of molybdenum, cobalt, and boron on node formation, yield, yield components, and morpho-phenological traits of soybean (Saman cultivar). The experiment was carried out in a factorial randomized complete block design at Golestan Agricultural and Natural Resources Research Center in 2018 and 2019 in three replications. The results showed that experimental treatments had a significant effect on the measured traits. Most of the measured traits, including yield, under the influence of seed treatment with bacteria azospirillum and cobalt, molybdenum, boron showed more increase than the control. It was found that under humic treatment, application of bacteria and nutrients can be effective on improvement of seed yield, so the highest seed yield mean (3268 kg/ha) was obtained by humic acid + Rhizobium+Azospirillum + Co+Mo+B treatments. Also, the highest protein yield mean was obtained by humic acid + Rhizobium + Co+Mo+B treatments (1103 kg/ha) and highest mean of oil yield was obtained by humic acid + Rhizobium+Azospirillum + Co+Mo treatments (577 kg/ha). Overall, the results of this study confirmed the efficiency of nitrogen-fixing bacteria as well as foliar application of micronutrients in increasing soybean yield per unit area. [ABSTRACT FROM AUTHOR]

Plant growth-promoting rhizobacteria (PGPR) can be used to increase plant growth rates in natural field conditions, as well as in micropropagation of plants in vitro and in substrate-free aero/hydroponic systems. This study demonstrates the ability of rhizobacteria Azospirillum baldaniorum Sp245 and Kocuria rosea T1Ks19 to stimulate the cultivation of potato microplants of the 'Nevsky' and 'Kondor' cultivars in in vitro culture, to increase the rate of adaptation of microplants to unsterile conditions of aeroponics ex vitro, and also to increase the productivity of minitubers. The conclusions obtained are based on the results of morphometric analysis of microplants, cytological analysis of stomata and biochemical assessment of the content of antioxidant enzymes (catalase, peroxidase and ascorbate peroxidase), as well as hydrogen peroxide and malondialdehyde in the leaves. The presence of bacteria on plant roots was monitored using enzyme immunoassay and CFU counting methods. It has been established that inoculation with the used combination of rhizobacteria stimulates the synthesis of antioxidant enzymes in microplants under stressful conditions, which leads to a decrease in the level of hydrogen peroxide. As a result, the adaptation efficiency, growth rates and productivity of micro-plants increase. It is recommended to inoculate potato microplants with A. baldaniorum Sp245 and K. rosea T1Ks19 strains at the stage of in vitro cultivation in the production of healthy seed material based on aeroponics in the potato seed production system. [ABSTRACT FROM AUTHOR]

Pesticide treatment leads to a significant increase in wheat yield and enhances pest resistance. However, pesticides, particularly the insecticide cypermethrin, which is used for wheat Triticum aestivum L. field and grain storage treatment, are toxic xenobiotics. To reduce their toxicity, it is possible to pre-treat seeds with plant growth-promoting rhizobacteria (PGPR), which can enhance plant resistance to adverse environmental factors. In this study, we used a previously unused as PGPR representative of the genus Azospirillum, A. thiophilum BV-ST, isolated in Russia, which makes it interesting for agricultural use in the same climatic zone. We optimized the detection method of A. thiophilum using PCR. Then, we demonstrated that this bacterium successfully inoculates to wheat roots. We showed that cypermethrin treatment of one- and two-week-old wheat seedlings caused an increase in mtDNA damage, and in one-week-old seedlings, it induced a decrease in chlorophyll levels. However, three- and four-week-old seedlings were more resistant to damage, possibly due to their approximately 5-fold higher expression of NDOR-1 and GST genes, which play an important role in xenobiotic detoxification. Pre-treatment of wheat seeds with A. thiophilum contributed to the upregulation of NDOR-1 and GST gene expression in one- and two-week-old seedlings, resulting in the protection of mtDNA from cypermethrin-induced damage and prevented the decrease in chlorophyll levels. [ABSTRACT FROM AUTHOR]

Aldehyde dehydrogenases (ALDHs) are indispensable enzymes that play a pivotal role in mitigating aldehyde toxicity by converting them into less reactive compounds. Despite the availability of fully sequenced Azospirillum genomes in public databases, a comprehensive analysis of the ALDH superfamily within these genomes has yet to be undertaken. This study presents the identification and classification of 17 families and 31 subfamilies of ALDHs in fully assembled Azospirillum genomes. This classification system framework provides a more comprehensive understanding of the diversity and redundancy of ALDHs across bacterial genomes, which can aid in elucidating the distinct characteristics and functions of each family. The study also proposes the adoption of the ALDH19 family as a powerful phylogenetic marker due to its remarkable conservation and non-redundancy across various Azospirillum species. The diversity of ALDHs among different strains of Azospirillum can influence their adaptation and survival under various environmental conditions. The findings of this study could potentially be used to improve agricultural production by enhancing the growth and productivity of crops. Azospirillum bacteria establish a mutualistic relationship with plants and can promote plant growth by producing phytohormones such as indole-3-acetic acid (IAA). The diversity of ALDHs in Azospirillum can affect their ability to produce IAA and other beneficial compounds that promote plant growth and can be used as biofertilizers to enhance agricultural productivity. [ABSTRACT FROM AUTHOR]

A field experiment entitled "Effect of Bio-fertilisers on Growth, Quality, and Yield of Broccoli (Brassica oleracea L. var. italica)" was conducted at Lovely Professional University, Punjab in 2021-2022. The experiment was laid out in a factorial randomized block design with 13 treatments and replicated three times. The result showed that maximum plant height (21.10 cm, 27.03 cm, 30.73 cm), number of leaves (7.33, 11.53, 13.20) at 30 DAT, 60 DAT, and at harvest, maximum stem diameter (2.85 cm), SPAD value at 45 DAT (56.50) and 60 DAT (66.60) and days to maturity (75.60) were found to be maximum in T12 (50% RDF + Azospirillum + Azotobacter + VAM+ PSB). Similarly, yield parameters, i.e., maximum curd diameter (12.25 cm), average curd weight (300.66 g), yield of curd per plot (2.99 g), total yield of curd per hectare (147.65 q) and dry matter content (12.47%), were found to be maximal in T12. An application of T12 (50% RDF + Azospirillum + Azotobacter + VAM + PSB) gave the highest net return (Rs. 660,325.90), followed by Rs. 630,696.30 under the treatment T11 (50% RDF + Azospirillum + Azotobacter + VAM) and the highest benefit-to-cost ratio (2.84), which was statistically significant over other treatments. The study shows the great potential of organics and biofertilizers that could be used for integrated nutrient management in broccoli. [ABSTRACT FROM AUTHOR]

The selection and deployment of microorganisms in stressed ecosystems with biocontrol ability is a major challenge. In this investigation, we sought to isolate and identify strains of Azotobacter and Azospirillum spp., which could withstand abiotic stresses and possess the potential to serve as biological control against five phytopathogenic fungi. Stress tolerance was evidently less obvious in Azospirillum strains than in Azotobacter strains, when bacterial strains were screened for high temperature (50 °C), salt (7% NaCl), and drought (1.2 MPa). Strains Asp30 and Asp 32 of Azospirillum and Azb 19, Azb20 and Azb27 of Azotobacter were found tolerant to temperature, drought and salinity stresses. Five strains of Azotobacter viz. Azb2, Azb6, Azb10, Azb16 and Azb18 and six strains of Azospirillum viz. Asp2, Asp10, Asp22, Asp30, Asp32 and Asp39 inhibited all the five fungal phytopathogens studied. Therefore, in vitro screening provided the basis for identification and selection of strains with abiotic stress tolerance and biocontrol ability. [ABSTRACT FROM AUTHOR]

The enhancing effect of N2-fixing bacterial strains in the presence of mineral N doses on maize plants in pots and field trials was investigated. The OT-H1 of 10 isolates maintained the total nitrogen, nitrogenase activities, IAA production, and detection of NH3 in their cultures. In addition, they highly promoted the germination of maize grains in plastic bags compared to the remainder. Therefore, OT-H1 was subjected for identification and selected for further tests. Based on their morphological, cultural, and biochemical traits, they belonged to the genera Azotobacter. The genomic sequences of 16S rRNA were, thus, used to confirm the identification of the genera. Accordingly, the indexes of tree and similarity for the related bacterial species indicated that genera were exactly closely linked to Azotoacter salinestris strain OR512393. In pot (35 days) and field (120 days) trials, the efficiencies of both A. salinestris and Azospirillum oryzea SWERI 111 (sole/dual) with 100, 75, 50, and 25% mineral N doses were evaluated with completely randomized experimental design and three repetitions. Results indicated that N2-fixing bacteria in the presence of mineral N treatment showed pronounced effects compared to controls. A high value of maize plants was also noticed through increasing the concentration of mineral N and peaked at a dose of 100%. Differences among N2-fixing bacteria were insignificant and were observed for A. oryzea with different mineral N doses. Thus, the utilization of A. oryzea and A. salinestris in their dual mix in the presence of 75 followed by 50% mineral N was found to be the superior treatments, causing the enhancement of vegetative growth and grain yield parameters of maize plants. Additionally, proline and the enzyme activities of both polyphenol oxidase (PPO) and peroxidase (PO) of maize leaves were induced, and high protein contents of maize grains were accumulated due to the superior treatments. The utilization of such N2-fixing bacteria was, therefore, found to be effective at improving soil fertility and to be an environmentally safe strategy instead, or at least with low doses, of chemical fertilizers. [ABSTRACT FROM AUTHOR]

The introduction of legumes into rotations can improve nitrogen use efficiency and crop yield; however, its microbial mechanism involved remains unclear. This study aimed to explore the temporal impact of peanut introduction on microorganisms related to nitrogen metabolism in rotation systems. In this study, the dynamics of diazotrophic communities in two crop seasons and wheat yields of two rotation systems: winter wheat – summer maize (WM) and spring peanut → winter wheat – summer maize (PWM) in the North China Plain were investigated. Our results showed that peanut introduction increased wheat yield and biomass by 11.6% (p < 0.05) and 8.9%, respectively. Lower Chao1 and Shannon indexes of the diazotrophic communities were detected in soils that sampling in June compared with those sampling in September, although no difference was found between WM and PWM. Principal co-ordinates analysis (PCoA) showed that rotation system significantly changed the diazotrophic community structures (PERMANOVA; p < 0.05). Compared with WM, the genera of Azotobacter, Skermanella, Azohydromonas, Rhodomicrobium, Azospirillum, Unclassified_f_Opitutaceae, and Unclassified_f_Rhodospirillaceae were significantly enriched (p < 0.05) in PWM. Furthermore, rotation system and sampling time significantly influenced soil properties, which significantly correlated with the top 15 genera in relative abundance. Partial least squares path modeling (PLS-PM) analysis further showed that the diazotrophic community diversity (alpha- and beta-diversity) and soil properties (pH, SOC and TN) significantly affected wheat yield. In conclusion, legume inclusion has the potential to stabilize diazotrophic community structure at the temporal scales and increase subsequent crop yield. [ABSTRACT FROM AUTHOR]