ABSTRACT
In this comprehensive investigation, we successfully isolated and characterized 40 distinct plant-associated halotolerant bacteria strains obtained from three halophytic plant species: Tamarix nilotica, Suaeda pruinosa, and Arthrocnemum macrostachyum. From this diverse pool of isolates, we meticulously selected five exceptional plant-associated halotolerant bacteria strains through a judiciously designed seed biopriming experiment and then identified molecularly. Bacillus amyloliquefaciens DW6 was isolated from A. macrostachyum. Three bacteria (Providencia rettgeri DW3, Bacillus licheniformis DW4, and Salinicoccus sesuvii DW5) were isolated for the first time from T. nilotica, S. pruinosa and S. pruinosa, respectively. Paenalcaligenes suwonensis DW7 was isolated for the first time from A. macrostachyum. These plant-associated halotolerant bacteria exhibited growth-promoting activities, including phosphate solubilization, nitrogen fixation, and production of bioactive compounds, i.e., ammonia, phytohormones, hydrogen cyanide, siderophores, and exopolysaccharides. A controlled laboratory experiment was conducted to reduce the detrimental impact of soil salinity. Vicia faba seedlings were inoculated individually or in mixtures by the five most effective plant-associated halotolerant bacteria to reduce the impact of salt stress and improve growth parameters. The growth parameters were significantly reduced due to the salinity stress in the control samples, compared to the experimental ones. The unprecedented novelty of our findings is underscored by the demonstrable efficacy of co-inoculation with these five distinct bacterial types as a pioneering bio-approach for countering the deleterious effects of soil salinity on plant growth. This study thus presents a remarkable contribution to the field of plant science and offers a promising avenue for sustainable agriculture in saline environments.
Subject(s)
Salinity , Vicia faba , Vicia faba/growth & development , Vicia faba/microbiology , Salt-Tolerant Plants/microbiology , Salt-Tolerant Plants/growth & development , Nitrogen Fixation , Bacteria/growth & development , Bacteria/metabolism , Bacteria/classification , Tamaricaceae/microbiology , Tamaricaceae/growth & development , Chenopodiaceae/microbiology , Chenopodiaceae/growth & development , Soil Microbiology , Salt Tolerance , Phosphates/metabolismABSTRACT
Modern intensive cropping systems often contribute to the accumulation of phenolic acids in the soil, which promotes the development of soilborne diseases. This can be suppressed by intercropping. This study analyzed the effects of intercropping on Fusarium wilt based on its effect on photosynthesis under stress by the combination of Fusarium commune and cinnamic acid. The control was not inoculated with F. commune, while the faba bean plants (Vicia faba L.) were inoculated with this pathogen in the other treatments. The infected plants were also treated with cinnamic acid. This study examined the development of Fusarium wilt together with its effects on the leaves, absorption of nutrients, chlorophyll fluorescence parameters, contents of photosynthetic pigments, activities of photosynthetic enzymes, gas exchange parameters, and the photosynthetic assimilates of faba bean from monocropping and intercropping systems. Under monocropping conditions, the leaves of the plants inoculated with F. commune grew significantly less, and there was enhanced occurrence of the Fusarium wilt compared with the control. Compared with the plants solely inoculated with F. commune, the exogenous addition of cinnamic acid to the infected plants significantly further reduced the growth of faba bean leaves and increased the occurrence of Fusarium wilt. A comparison of the combination of F. commune and cinnamic acid in intercropped wheat and faba bean compared with monocropping showed that intercropping improved the absorption of nutrients, increased photosynthetic pigments and its contents, electron transport, photosynthetic enzymes, and photosynthetic assimilates. The combination of these factors reduced the occurrence of Fusarium wilt in faba bean and increased the growth of its leaves. These results showed that intercropping improved the photosynthesis, which promoted the growth of faba bean, thus, reducing the development of Fusarium wilt following the stress of infection by F. commune and cinnamic acid. This research should provide more information to enhance sustainable agriculture.
Subject(s)
Cinnamates , Fusarium , Photosynthesis , Plant Diseases , Vicia faba , Fusarium/physiology , Vicia faba/microbiology , Vicia faba/physiology , Cinnamates/metabolism , Cinnamates/pharmacology , Plant Diseases/microbiology , Stress, Physiological , Plant Leaves/microbiology , Crop Production/methods , Chlorophyll/metabolism , Crops, Agricultural/microbiologyABSTRACT
The bean yellow mosaic virus (BYMV) is one of the most serious economic diseases affecting faba bean crop production. Rhizobium spp., well known for its high nitrogen fixation capacity in legumes, has received little study as a possible biocontrol agent and antiviral. Under greenhouse conditions, foliar application of molecularly characterized Rhizobium leguminosarum bv. viciae strain 33504-Borg201 to the faba bean leaves 24 h before they were infected with BYMV made them much more resistant to the disease while also lowering its severity and accumulation. Furthermore, the treatment promoted plant growth and health, as evidenced by the increased total chlorophyll (32.75 mg/g f.wt.) and protein content (14.39 mg/g f.wt.), as well as the improved fresh and dry weights of the plants. The protective effects of 33504-Borg201 greatly lowered the levels of hydrogen peroxide (H2O2) (4.92 µmol/g f.wt.) and malondialdehyde (MDA) (173.72 µmol/g f.wt.). The antioxidant enzymes peroxidase (1.58 µM/g f.wt.) and polyphenol oxidase (0.57 µM/g f.wt.) inhibited the development of BYMV in plants treated with 33504-Borg201. Gene expression analysis showed that faba bean plants treated with 33504-Borg201 had higher amounts of pathogenesis-related protein-1 (PR-1) (3.28-fold) and hydroxycinnamoyl-CoA quinate hydroxycinnamoyltransferase (4.13-fold) than control plants. These findings demonstrate the potential of 33,504-Borg201 as a cost-effective and eco-friendly method to protect faba bean plants against BYMV. Implementing this approach could help develop a simple and sustainable strategy for protecting faba bean crops from the devastating effects of BYMV.
Subject(s)
Plant Diseases , Plant Leaves , Rhizobium leguminosarum , Vicia faba , Rhizobium leguminosarum/genetics , Rhizobium leguminosarum/growth & development , Rhizobium leguminosarum/physiology , Vicia faba/virology , Vicia faba/microbiology , Plant Diseases/microbiology , Plant Diseases/virology , Plant Diseases/prevention & control , Plant Leaves/microbiology , Plant Leaves/virology , Disease Resistance , Hydrogen Peroxide/metabolismABSTRACT
Reducing the content of quickly absorbed carbohydrates and saturated fats in snack formulations while increasing the consumption of high-quality proteins are effective strategies to prevent obesity in childhood. Thus, the nutritional value, digestibility, and functionality of fava beans (Vicia faba L.) fermented with Pleurotus ostreatus were examined as potential ingredients for food design. Solid-state fermentation enhanced the protein content by 16% with a rise in essential (25%) and non-essential (15%) amino acids while decreasing total carbohydrate content and tannin levels. Moreover, fermentation modified the amino acid profile released during digestion, increasing amino acids such as valine, isoleucine, and threonine, which are vital for health and development in childhood. Furthermore, the bioaccessible fraction of the fermented bean showed a 60% of ACE inhibition and improved magnesium bioaccessibility. Consequently, fava beans fermented with Pleurotus ostreatus emerged as a new ingredient in the development of new protein-rich snacks tailored for children and adolescents.
Subject(s)
Angiotensin-Converting Enzyme Inhibitors , Digestion , Fermentation , Vicia faba , Humans , Amino Acids/metabolism , Amino Acids/analysis , Angiotensin-Converting Enzyme Inhibitors/metabolism , Angiotensin-Converting Enzyme Inhibitors/chemistry , Models, Biological , Nutritive Value , Pleurotus/metabolism , Pleurotus/chemistry , Pleurotus/growth & development , Vicia faba/chemistry , Vicia faba/metabolism , Vicia faba/microbiologyABSTRACT
In Tunisia, Orobanche foetida Poir. is considered an important agricultural biotic constraint on faba bean (Vicia faba L.) production. An innovative control method for managing this weed in faba bean is induced resistance through inoculation by rhizobia strains. In this study, we explored the biochemical dynamics in V. faba L. minor inoculated by rhizobia in response to O. foetida parasitism. A systemic induced resistant reaction was evaluated through an assay of peroxidase (POX), polyphenol oxidase (PPO) and phenyl alanine ammonialyase (PAL) activity and phenolic compound and hydrogen peroxide (H2O2) accumulation in faba bean plants infested with O. foetida and inoculated with rhizobia. Two rhizobia strains (Mat, Bj1) and a susceptible variety of cultivar Badi were used in a co-culture Petri dish experiment. We found that Mat inoculation significantly decreased O. foetida germination and the number of tubercles on the faba bean roots by 87% and 88%, respectively. Following Bj1 inoculation, significant decreases were only observed in O. foetida germination (62%). In addition, Mat and Bj1 inoculation induced a delay in tubercle formation (two weeks) and necrosis in the attached tubercles (12.50% and 4.16%, respectively) compared to the infested control. The resistance of V. faba to O. foetida following Mat strain inoculation was mainly associated with a relatively more efficient enzymatic antioxidative response. The antioxidant enzyme activity was enhanced following Mat inoculation of the infected faba bean plant. Indeed, increases of 45%, 67% and 86% were recorded in the POX, PPO and PAL activity, respectively. Improvements of 56% and 12% were also observed in the soluble phenolic and H2O2 contents. Regarding inoculation with the Bj1 strain, significant increases were only observed in soluble phenolic and H2O2 contents and PPO activity (especially at 45 days after inoculation) compared to the infested control. These results imply that inoculation with the rhizobia strains (especially Mat) induced resistance and could bio-protect V. faba against O. foetida parasitism by inducing systemic resistance, although complete protectionwas not achieved by rhizobia inoculation. The Mat strain could be used as a potential candidate for the development of an integrated method for controlling O. foetida parasitism in faba bean.
Subject(s)
Hydrogen Peroxide , Orobanche , Vicia faba , Vicia faba/microbiology , Vicia faba/parasitology , Vicia faba/metabolism , Hydrogen Peroxide/metabolism , Catechol Oxidase/metabolism , Plant Roots/microbiology , Plant Roots/parasitology , Plant Roots/metabolism , Rhizobium/physiology , Peroxidase/metabolism , Plant Diseases/parasitology , Plant Diseases/microbiology , Phenylalanine Ammonia-Lyase/metabolismABSTRACT
As a legume crop widely cultured in the world, faba bean (Vicia faba L.) forms root nodules with diverse Rhizobium species in different regions. However, the symbionts associated with this plant in Mexico have not been studied. To investigate the diversity and species/symbiovar affiliations of rhizobia associated with faba bean in Mexico, rhizobia were isolated from this plant grown in two Mexican sites in the present study. Based upon the analysis of recA gene phylogeny, two genotypes were distinguished among a total of 35 isolates, and they were identified as Rhizobium hidalgonense and Rhizobium redzepovicii, respectively, by the whole genomic sequence analysis. Both the species harbored identical nod gene cluster and the same phylogenetic positions of nodC and nifH. So, all of them were identified into the symbiovar viciae. As a minor group, R. hidalgonense was only isolated from slightly acid soil and R. redzepovicii was the dominant group in both the acid and neutral soils. In addition, several genes related to resistance to metals (zinc, copper etc.) and metalloids (arsenic) were detected in genomes of the reference isolates, which might offer them some adaptation benefits. As conclusion, the community composition of faba bean rhizobia in Mexico was different from those reported in other regions. Furthermore, our study identified sv. viciae as the second symbiovar in the species R. redzepovicii. These results added novel evidence about the co-evolution, diversification and biogeographic patterns of rhizobia in association with their host legumes in distinct geographic regions.
Subject(s)
Phylogeny , Rhizobium , Soil Microbiology , Symbiosis , Vicia faba , Vicia faba/microbiology , Rhizobium/genetics , Rhizobium/isolation & purification , Rhizobium/classification , Mexico , Bacterial Proteins/genetics , Root Nodules, Plant/microbiology , Soil/chemistry , N-Acetylglucosaminyltransferases/genetics , Oxidoreductases/genetics , Rec A Recombinases/genetics , Multigene FamilyABSTRACT
Ascochyta blight, caused by Ascochyta fabae, poses a significant threat to faba bean and other legumes worldwide. Necrotic lesions on stems, leaves, and pods characterize the disease. Given the economic impact of this pathogen and the potential involvement of secondary metabolites in symptom development, a study was conducted to investigate the fungus's ability to produce bioactive metabolites that might contribute to its pathogenicity. For this investigation, the fungus was cultured in three substrates (Czapek-Dox, PDB, and rice). The produced metabolites were analyzed by NMR and LC-HRMS methods, resulting in the dereplication of seven metabolites, which varied with the cultural substrates. Ascochlorin, ascofuranol, and (R)-mevalonolactone were isolated from the Czapek-Dox extract; ascosalipyrone, benzoic acid, and tyrosol from the PDB extract; and ascosalitoxin and ascosalipyrone from the rice extract. The phytotoxicity of the pure metabolites was assessed at different concentrations on their primary hosts and related legumes. The fungal exudates displayed varying degrees of phytotoxicity, with the Czapek-Dox medium's exudate exhibiting the highest activity across almost all legumes tested. The species belonging to the genus Vicia spp. were the most susceptible, with faba bean being susceptible to all metabolites, at least at the highest concentration tested, as expected. In particular, ascosalitoxin and benzoic acid were the most phytotoxic in the tested condition and, as a consequence, expected to play an important role on necrosis's appearance.
Subject(s)
Fabaceae , Toxins, Biological , Vicia faba , Fabaceae/microbiology , Vicia faba/microbiology , Vegetables , Crops, Agricultural , Benzoic Acid , Plant ExtractsSubject(s)
Levilactobacillus brevis , Vicia faba , Vicia faba/microbiology , Antifungal Agents , Flour/microbiology , Bread/microbiology , Triticum , Peptides , FermentationABSTRACT
BACKGROUND: Broad bean paste is a high nitrogen and high salt traditional Chinese condiment, which triggers biosynthesis of nitrogen hazards like biogenic amines (BAs). Mechanisms of association and applied research of functional safety and community assembly within multiple-microbial fermentation are currently lacking. Here, bioaugmentation was performed based on the profiles of BAs accumulation and microbial succession to evaluate the functional variation within broad bean paste fermentation. RESULTS: Putrescine, spermine, and spermidine were the main BAs during traditional broad bean paste fermentation. Staphylococcus, Streptococcus, Lactococcus, Lactobacillus, Leuconostoc, and Bacillus were the predominant bacteria, whereas Aspergillus and Zygosaccharomyces dominated in fungal species, and community structure shifted upon salt exposure. PICRUSt software uncovered that Bacillus contributed significantly (>1%) to the amine oxidase gene family. Bacillus amyloliquefaciens 1-G6 and Bacillus licheniformis 2-B3 were screened to perform the bioaugmentation of broad bean paste, which achieved a 29% and 16% BA decrease respectively. Interaction network analysis showed that Cronobacter and Lactobacillus were significantly negatively correlated with Bacillus (ρ = -0.829 and ρ = -0.714, respectively, P < 0.05) in the B. amyloliquefaciens 1-G6 group, and Staphylococcus and Buttiauxella were inhibited by Bacillus (ρ = -0.657 and ρ = -0.543, respectively, P < 0.05) in the B. licheniformis 2-B3 group. CONCLUSION: The synergism of amine oxidase activity and microbial interactions led to the decline of BAs. Thus, this study improves our understanding of the underlying mechanisms of microbial succession and functional variation to further facilitate the optimization of the fermented food industry.
Subject(s)
Bacillus , Fabaceae , Vicia faba , Bacillus/genetics , Fermentation , Biogenic Amines , Vicia faba/microbiology , OxidoreductasesABSTRACT
Drought is an environmental stress that strongly impacts plants. It affects all stages of growth and induces profound disturbances that influence all cellular functions. Legumes can establish a symbiosis with Rhizobium-type bacteria, whose function is to fix atmospheric nitrogen in organs called nodules and to meet plant nitrogen needs. Symbiotic nitrogen fixation (SNF) is particularly sensitive to drought. We raised the hypothesis that, in drought-stressed nodules, SNF inhibition is partly correlated to hypoxia resulting from nodule structure compaction and an increased O2 diffusion barrier, and that the nodule energy regeneration involves phytoglobin-nitric oxide (Pgb-NO) respiration. To test this hypothesis, we subjected faba bean (Vicia faba L.) plants nodulated with a Rhizobium laguerreae strain to either drought or osmotic stress. We monitored the N2-fixation activity, the energy state (ATP/ADP ratio), the expression of hypoxia marker genes (alcohol dehydrogenase and alanine aminotransferase), and the functioning of the Pgb-NO respiration in the nodules. The collected data confirmed our hypothesis and showed that (1) drought-stressed nodules were subject to more intense hypoxia than control nodules and (2) NO production increased and contributed via Pgb-NO respiration to the maintenance of the energy state of drought-stressed nodules.
Subject(s)
Vicia faba , Droughts , Hypoxia/metabolism , Metabolic Networks and Pathways , Nitric Oxide/metabolism , Nitrogen/metabolism , Nitrogen Fixation/physiology , Plants/metabolism , Root Nodules, Plant/metabolism , Symbiosis/physiology , Vicia faba/microbiologyABSTRACT
Rhizosphere soil microbial community and its diversity are important for the structure and functions of medicinal plant ecosystem. In this study, based on high-throughput sequencing, rhizosphere soil microbial diversity, and yield and quality of rhizome and root of Notopterygium incisum cultivated alone(control, CK) and intercropped with Vicia faba(QH) were analyzed, which is expected to lay a basis for optimization of the cultivation mode and ecological production of N. incisum. RESULTS:: showed that the rhizosphere soil bacteria of N. incisum were dominated by Proteobacteria and Bacteroides, with the relative abundance of 50.38%-51.95% and 16.36%-17.02%, respectively. Soil bacterial community at the phylum level was not significantly different between CK and QH. At the genus level, the relative abundance of MND1(3.54%), Spinstomonas(3.50%), Nitrospira(1.53%), and Rhizobacter(1.05%) was significantly higher and that of Gemmatimonas, Candidatus_Solibacter, and Bryophytes was lower in QH treatment than in the CK. The plant height, leaf length, leaf width, and petiole length of N. incisum in QH treatment was significantly increased and the underground biomass rose by 71.43% compared with those in the CK. Thus, intercropping with V. faba promoted the aboveground growth of N. incisum and improved the yield of root and rhizome. Moreover, the content of notopterol and isoimperatorin increased by 37.96% and 4.09% in QH treatment, respectively, indicating that the intercropping with V. faba boosted the accumulation of secondary metabolites in N. incisum. Pearson's correlation analysis showed that the soil bacterial community was mainly influenced by the soil factors including the content of soil available nutrients, soil organic matter, pH value, and soil water. The influence was in the order: total potassium>total nitrogen>pH>organic matter>available potassium>soil water content>available nitrogen>available phosphorus. In conclusion, the intercropping with V. faba altered soil microenvironment and also increased the yield and accumulation of secondary metabolites of N. incisum, which is a promising ecological planting model for N. incisum.
Subject(s)
Apiaceae , Vicia faba , Agriculture , Apiaceae/metabolism , Ecosystem , Nitrogen/metabolism , Plant Roots , Potassium , Rhizosphere , Soil/chemistry , Soil Microbiology , Vicia faba/metabolism , Vicia faba/microbiology , Water/metabolismABSTRACT
Water deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield-related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.
Subject(s)
Acclimatization , Pseudomonas putida/growth & development , Rhizobium leguminosarum/growth & development , Soil Microbiology , Vicia faba , Dehydration/metabolism , Dehydration/microbiology , Vicia faba/genetics , Vicia faba/growth & development , Vicia faba/microbiologyABSTRACT
BACKGROUND: Ascochyta blight caused by Ascochyta fabae Speg. and broomrape (Orobanche crenata) are among the economically most significant pathogens of faba bean. Several QTLs conferring resistance against the two pathogens have been identified and validated in different genetic backgrounds. The aim of this study was to saturate the most stable QTLs for ascochyta and broomrape resistance in two Recombinant Inbred Line (RIL) populations, 29H x Vf136 and Vf6 x Vf136, to identify candidate genes conferring resistance against these two pathogens. RESULTS: We exploited the synteny between faba bean and the model species Medicago truncatula by selecting a set of 219 genes encoding putative WRKY transcription factors and defense related proteins falling within the target QTL intervals, for genotyping and marker saturation in the two RIL populations. Seventy and 50 of the candidate genes could be mapped in 29H x Vf136 and Vf6 x Vf136, respectively. Besides the strong reduction of the QTL intervals, the mapping process allowed replacing previous dominant and pedigree-specific RAPD flanking markers with robust and transferrable SNP markers, revealing promising candidates for resistance against the two pathogens. CONCLUSIONS: Although further efforts in association mapping and expression studies will be required to corroborate the candidate genes for resistance, the fine-mapping approach proposed here increases the genetic resolution of relevant QTL regions and paves the way for an efficient deployment of useful alleles for faba bean ascochyta and broomrape resistance through marker-assisted breeding.
Subject(s)
Ascomycota/pathogenicity , Disease Resistance/genetics , Medicago truncatula/genetics , Orobanche/parasitology , Quantitative Trait Loci , Vicia faba/genetics , Vicia faba/microbiology , Vicia faba/parasitology , Crops, Agricultural/genetics , Crops, Agricultural/microbiology , Crops, Agricultural/parasitology , Gene Expression Regulation, Plant , Genes, Plant , Genetic Markers , Genetic Variation , SyntenyABSTRACT
Aphanomyces euteiches is an oomycete pathogen that causes the pea root rot. We investigated the potential role of early belowground defense in pea (susceptible plant) and faba bean (tolerant plant) at three days after inoculation. Pea and faba bean were inoculated with A. euteiches zoospores. Root colonization was examined. Root exudates from pea and faba bean were harvested and their impact on A. euteiches development were assessed by using in vitro assays. A. euteiches root colonization and the influence of the oomycete inoculation on specialized metabolites patterns and arabinogalactan protein (AGP) concentration of root exudates were also determined. In faba bean root, A. euteiches colonization was very low as compared with that of pea. Whereas infected pea root exudates have a positive chemotaxis index (CI) on zoospores, faba bean exudate CI was negative suggesting a repellent effect. While furanoacetylenic compounds were only detected in faba bean exudates, AGP concentration was specifically increased in pea.This work showed that early in the course of infection, host susceptibility to A. euteiches is involved via a plant-species specific root exudation opening new perspectives in pea root rot disease management.
Subject(s)
Aphanomyces/drug effects , Aphanomyces/growth & development , Pisum sativum/microbiology , Plant Exudates/pharmacology , Plant Roots/microbiology , Vicia faba/chemistry , Vicia faba/microbiology , Virulence/drug effects , Crops, Agricultural/microbiology , Host-Pathogen Interactions/drug effects , Plant Immunity/drug effectsABSTRACT
<b>Background and Objective:</b> Rhizobia are bacteria including genes codes for enzymes involved in the fixing of the atmospheric nitrogen. A set of twenty rhizobial isolates were studied to determine their morphological, biochemical, molecular characteristics using the 16S rRNA gene in addition to assess their growth and symbiotic performance. <b>Materials and Methods:</b> Rhizobial isolates were isolated from root nodules of <i>Vicia faba </i>L. plants. The isolates were morphologically characterized by determining cell shapes, size, Gram stain reaction, motility, sporulation, bacterial growth performance was determined by IAA production and biomass density. Symbiotic performance was measured by evaluation of nodulation status and shoot/root dry weight. Sequencing of 16S rRNA and phylogenetic analysis were done for the five promising isolates. Statistical analysis was performed using a one-sample Student t-test. <b>Results:</b> Only five rhizobial isolates (Rh 32, Rh 6-A, Rh 3-4, Rh RL3 and Rh 8-A) were selected according to their growth and symbiotic performance and subjected to further molecular characterizations. All isolates were found to have remarkable nodulation status, IAA production, nitrogenase activity and increasing the root and shoot dry weight. The five selected rhizobial isolates were identified by partial sequencing of 16S rRNA genes and registered in the GenBank database. The alignment and phylogenetic analyses of 16S rRNA sequences closely related in the GenBank revealed that all isolates belonging to <i>Rhizobium leguminosarum</i> bv. viciae. <b>Conclusion:</b> The results confirmed that the five Rhizobial strains will be promising as a source of genes for nitrogen fixation and plant growth promotion.
Subject(s)
Plant Roots/microbiology , Rhizobium leguminosarum , Vicia faba/microbiology , Egypt , Nitrogen Fixation , Phylogeny , Plant Root Nodulation , Plant Roots/growth & development , Rhizobium leguminosarum/genetics , Rhizobium leguminosarum/growth & development , Rhizobium leguminosarum/metabolism , Ribotyping , Symbiosis , Vicia faba/growth & development , Vicia faba/metabolismABSTRACT
Plant Growth-Promoting Rhizobacteria (PGPR) induce systemic resistance (SR) in plants, decreasing the development of phytopathogens. The FZB42 strain of Bacillus velezensis is known to induce an SR against pathogens in various plant species. Previous studies suggested that it could also influence the interactions between plants and associated pests. However, insects have developed several strategies to counteract plant defenses, including salivary proteins that allow the insect escaping detection, manipulating defensive pathways to its advantage, deactivating early signaling processes, or detoxifying secondary metabolites. Because Brown Marmorated Stink Bug (BMSB) Halyomorpha halys is highly invasive and polyphagous, we hypothesized that it could detect the PGPR-induced systemic defenses in the plant, and efficiently adapt its salivary compounds to counteract them. Therefore, we inoculated a beneficial rhizobacterium on Vicia faba roots and soil, previous to plant infestation with BMSB. Salivary gland proteome of BMSB was analyzed by LC-MS/MS and a label-free quantitative proteomic method. Among the differentially expressed proteins, most were up-regulated in salivary glands of insects exposed to PGPR-treated plants for 24 h. We could confirm that BMSB was confronted with a stress during feeding on PGPR-treated plants. The to-be-confirmed defensive state of the plant would have been rapidly detected by the invasive H. halys pest, which consequently modified its salivary proteins. Among the up-regulated proteins, many could be associated with a role in plant defense counteraction, and more especially in allelochemicals detoxification or sequestration.
Subject(s)
Bacillus/growth & development , Heteroptera/metabolism , Salivary Proteins and Peptides/analysis , Vicia faba/microbiology , Animals , Chromatography, High Pressure Liquid , Heteroptera/growth & development , Larva/metabolism , Salivary Glands/metabolism , Stress, Physiological , Tandem Mass Spectrometry , Up-Regulation , Vicia faba/chemistry , Vicia faba/parasitologyABSTRACT
Several ascomycetous entomopathogenic fungi, including species in the genera Beauveria, are plant symbionts/endophytes and are termed as endophytic insect-pathogenic fungi. It was shown that the fungus Beauveria bassiana (BBK-1 strain) successfully colonized Vicia faba bean plants in laboratory and field conditions of Western Siberia. The B. bassiana reisolate passed through the plants had significantly higher antagonistic activity against phytopathogens in comparison with the primary stem of entomopahogenic fungi. Pre-sowing faba bean seeds treatment reduced the level of infection of the seed material with phytopathogens, significantly decrease the development and prevalence of root rot disease. A decrease in the disease development index (chocolate spot, powdery mildew, fusariosis and other spots diseases) was found as a result of the use of B. bassiana. The effectiveness and prolonged action of B. bassiana on plants opens up new opportunities both in the creation of biological products and in molecular-genetic research and selection of certain pairs of plants and fungi based on the principle of the greatest synergy.
Subject(s)
Beauveria/physiology , Plant Diseases/microbiology , Vicia faba/microbiology , Endophytes , Seeds/microbiologyABSTRACT
Vicia faba (faba bean) is one of the most significant leguminous crops. The faba bean is specialized by maximum nutritional value, in energy and protein content, which leads it to be suitable for food and feed production. Diseases caused with fungi are amongst the biotic factors responsible for decreasing in faba bean yields. In this work, Cladosporium isolates were recorded in cultivated faba bean leaves and pods collected from markets in Qena, Upper Egypt; morphological features and molecular characterization based on actin gene were performed. The ability of the pathogens to cause disease in faba bean seedlings and the biocontrol method to avoid the pathogenic effect of Cladosporium were determined. Results showed that Cladosporium is the main genera isolated from faba beans, and the morphological criteria showed presence of three species complex groups of Cladosporium (C. cladosporioides, C. herbarum and C. sphaerospermum) and the confirmation with molecular characterization revealed the existence of four species in the three groups. All the 26 tested strains of Cladosporium were able to cause leaf lesions on Vicia faba seedlings with different levels. Chaetomium globosum is a biocontrol agent could inhibit the growth of the majority strains of Cladosporium.
Subject(s)
Cladosporium/growth & development , Plant Diseases/microbiology , Vicia faba/microbiology , Biological Control Agents/metabolism , Chaetomium/growth & development , Chaetomium/isolation & purification , Cladosporium/genetics , Cladosporium/isolation & purification , Phylogeny , Seedlings/microbiologyABSTRACT
Faba bean (Vicia faba L.) is one of the earliest domesticated food legumes after chickpea and pea in the world. It is been produced in many countries including China, Ethiopia, Egypt, northern Europe, the Mediterranean region, central Asia, East Asia, Latin America and as a minor crop in India. The crop is affected by many diseases and alternaria leaf blight (Alternaria spp.) is one of the serious threat to faba bean production. Twenty-five lines of faba bean were selected from three international nurseries and were evaluated at ICARDA-FLRP-Amlaha during 2016-2017 and 2017-2018, to identify resistant lines against alternaria blight disease. A wide range of variation to disease reaction was observed among faba bean genotypes. One faba bean line (S2011-134) found tolerant, six genotypes (S2011-116, FLIP15-139, FLIP15-156, FLIP15-159, FLIP15-164-S2 and FLIP15-169) were found moderately tolerant and 16 genotypes were found susceptible to alternaria blight. The faba bean genotypes showed resistance to the disease scoring (0-9) with high yield as compared to the checks, Giza and Gwalior local. The identified sources of resistance can be utilized in faba bean breeding programmes for the development of disease tolerant cultivars with high yield.
Subject(s)
Disease Resistance/genetics , Plant Breeding , Plant Diseases/genetics , Vicia faba/genetics , Alternaria/pathogenicity , China , Europe , Genotype , India , Plant Diseases/microbiology , Vicia faba/growth & development , Vicia faba/microbiologyABSTRACT
Chinese horse bean-chili-paste (CHCP), a fermented condiment in China, is traditionally manufactured through naturally spontaneous semi-solid fermentation procedures without intentionally inoculated microorganisms. The aim of this study was to investigate the effect on microbiota and quality variations during CHCP fermentation by inoculation of selected autochthonous microorganisms Bacillus amyloliquefaciens and Candida versatilis. The results showed that relative abundance of Bacillus in the samples inoculated with B. amyloliquefaciens were increased from about 0.6% to almost 25%, and the batches bio-augmented with C. versatilis exhibited clearly 0.7 Lg copies/g higher biomass than that of the other samples. By bio-augmentation, six enzyme activities, namely acid protease, leucine aminopeptidase, α-amylase, cellulose, ß-glucosidase and esterase, were considerably enhanced. As a result, inoculation of these two strains exhibited significant effect on the volatile profiles of CHCP. B. amyloliquefaciens herein was found to contribute mainly to the accumulation of acids, sulfur-containing compounds and pyrazines, whereas C. versatilis was considerably associated with the formation of alcohols, esters and phenols. This study proved that combination of B. amyloliquefaciens and C. versatilis could obtain more extensive aroma profiles, especially for the enrichment of miso-like and fruity flavors, which could provide a guideline for the tailored control of CHCP fermentation process.