The Purified Siderophore from Streptomyces tricolor HM10 Accelerates Recovery from Iron-Deficiency-Induced Anemia in Rats.

Iron-deficiency-induced anemia is associated with poor neurological development, including decreased learning ability, altered motor functions, and numerous pathologies. Siderophores are iron chelators with low molecular weight secreted by microorganisms. The proposed catechol-type pathway was identified based on whole-genome sequences and bioinformatics tools. The intended pathway consists of five genes involved in the biosynthesis process. Therefore, the isolated catechol-type siderophore (Sid) from Streptomyces tricolor HM10 was evaluated through an anemia-induced rat model to study its potential to accelerate recovery from anemia. Rats were subjected to an iron-deficient diet (IDD) for 42 days. Anemic rats (ARs) were then divided into six groups, and normal rats (NRs) fed a standard diet (SD) were used as a positive control group. For the recovery experiment, ARs were treated as a group I; fed an IDD (AR), group II; fed an SD (AR + SD), group III, and IV, fed an SD with an intraperitoneal injection of 1 µg Sid Kg-1 (AR + SD + Sid1) and 5 µg Sid Kg-1 (AR + SD + Sid5) twice per week. Group V and VI were fed an iron-enriched diet (IED) with an intraperitoneal injection of 1 µg Sid Kg-1 (AR + IED + Sid1) and 5 µg Sid Kg-1 (AR + IED + Sid5) twice per week, respectively. Weight gain, food intake, food efficiency ratio, organ weight, liver iron concentration (LIC) and plasma (PIC), and hematological parameters were investigated. The results showed that ~50-60 mg Sid L-1 medium could be producible, providing ~25-30 mg L-1 purified Sid under optimal conditions. Remarkably, the AR group fed an SD with 5 µg Sid Kg-1 showed the highest weight gain. The highest feed efficiency was observed in the AR + SD + Sid5 group, which did not significantly differ from the SD group. Liver, kidneys, and spleen weight indicated that diet and Sid concentration were related to weight recovery in a dose-dependent manner. Liver iron concentration (LIC) in the AR + IED + Sid1 and AR + IED + Sid5 groups was considerably higher than in the AR + SD + Sid1 AR + SD + Sid5 groups or the AR + SD group compared to the AR group. All hematological parameters in the treated groups were significantly closely attenuated to SD groups after 28 days, confirming the efficiency of the anemia recovery treatments. Significant increases were obtained in the AR + SD + Sid5 and AR + IED + Sid5 groups on day 14 and day 28 compared to the values for the AR + SD + Sid1 and AR + IED + Sid1 groups. The transferrin saturation % (TSAT) and ferritin concentration (FC) were significantly increased with time progression in the treated groups associatively with PIC. In comparison, the highest significant increases were noticed in ARs fed IEDs with 5 µg Kg-1 Sid on days 14 and 28. In conclusion, this study indicated that Sid derived from S. tricolor HM10 could be a practical and feasible iron-nutritive fortifier when treating iron-deficiency-induced anemia (IDA). Further investigation focusing on its mechanism and kinetics is needed.

Quinoa Response to Application of Phosphogypsum and Plant Growth-Promoting Rhizobacteria under Water Stress Associated with Salt-Affected Soil.

The aim of the study was to estimate the impact of soil amendments (i.e., phosphogypsum and plant growth-promoting rhizobacteria (PGPR)) separately or their combination on exchangeable sodium percentage (ESP), soil enzymes' activity (urease and dehydrogenase), pigment content, relative water content (RWC), antioxidant enzymatic activity, oxidative stress, productivity, and quality of quinoa under deficient irrigation conditions in two field experiments during the 2019-2020 and 2020-2021 seasons under salt-affected soil. Results revealed that ESP, soil urease activity, soil dehydrogenase activity, leaf chlorophyll a, b, and carotenoids, leaf K content, RWC, SOD (superoxide dismutase), CAT (catalase), and POD (peroxidase) activities were declined, resulting in overproduction of leaf Na content, proline content, and oxidative stress indicators (H2O2, malondialdehyde (MDA) and electrolyte leakage) under water stress and soil salinity, which negatively influence yield-related traits, productivity, and seed quality of quinoa. However, amendment of salt-affected soil with combined phosphogypsum and seed inoculation with PGPR under deficient irrigation conditions was more effective than singular application and control plots in ameliorating the harmful effects of water stress and soil salinity. Additionally, combined application limited Na uptake in leaves and increased K uptake and leaf chlorophyll a, b, and carotenoids as well as improved SOD, CAT, and POD activities to ameliorate oxidative stress indicators (H2O2, MDA, and electrolyte leakage), which eventually positively reflected on productivity and quality in quinoa. We conclude that the potential utilization of phosphogypsum and PGPR are very promising as sustainable eco-friendly strategies to improve quinoa tolerance to water stress under soil salinity.

Molecular Genetic Diversity and Combining Ability for Some Physiological and Agronomic Traits in Rice under Well-Watered and Water-Deficit Conditions.

Water deficit is a pivotal abiotic stress that detrimentally constrains rice growth and production. Thereupon, the development of high-yielding and drought-tolerant rice genotypes is imperative in order to sustain rice production and ensure global food security. The present study aimed to evaluate diverse exotic and local parental rice genotypes and their corresponding cross combinations under water-deficit versus well-watered conditions, determining general and specific combining ability effects, heterosis, and the gene action controlling important traits through half-diallel analysis. In addition, the research aimed to assess parental genetic distance (GD) employing simple sequence repeat (SSR) markers, and to determine its association with hybrid performance, heterosis, and specific combining ability (SCA) effects. Six diverse rice genotypes (exotic and local) and their 15 F1 hybrids were assessed for two years under water-deficit and well-watered conditions. The results revealed that water-deficit stress substantially declined days to heading, plant height, chlorophyll content, relative water content, grain yield, and yield attributes. Contrarily, leaf rolling and the sterility percentage were considerably increased compared to well-watered conditions. Genotypes differed significantly for all the studied characteristics under water-deficit and well-watered conditions. Both additive and non-additive gene actions were involved in governing the inheritance of all the studied traits; however, additive gene action was predominant for most traits. The parental genotypes P1 and P2 were identified as excellent combiners for earliness and the breeding of short stature genotypes. Moreover, P3, P4, and P6 were identified as excellent combiners to increase grain yield and its attributes under water-deficit conditions. The hybrid combinations; P1 × P4, P2 × P5, P3 × P4, and P4 × P6 were found to be good specific combiners for grain yield and its contributed traits under water-deficit conditions. The parental genetic distance (GD) ranged from 0.38 to 0.89, with an average of 0.70. It showed lower association with hybrid performance, heterosis, and combining ability effects for all the studied traits. Nevertheless, SCA revealed a significant association with hybrid performance and heterosis, which suggests that SCA is a good predictor for hybrid performance and heterosis under water-deficit conditions. Strong positive relationships were identified between grain yield and each of relative water content, chlorophyll content, number of panicles/plant, number of filled grains/panicle, and 1000-grain weight. This suggests that these traits could be exploited as important indirect selection criteria for improving rice grain yield under water-deficit conditions.

Isolation, Identification, Biocontrol Activity, and Plant Growth Promoting Capability of a Superior Streptomyces tricolor Strain HM10.

Streptomyces is a genus with known biocontrol activity, producing a broad range of biologically active substances. Our goal was to isolate local Streptomyces species, evaluate their capacity to biocontrol the selected phytopathogens, and promote the plant growth via siderophore and indole acetic acid (IAA) production and phosphate solubilization. Eleven isolates were obtained from local soil samples in Saudi Arabia via the standard serial dilution method and identified morphologically by scanning electron microscope (SEM) and 16S rRNA amplicon sequencing. The biocontrol of phytopathogens was screened against known soil-borne fungi and bacteria. Plant growth promotion capacity was evaluated based on siderophore and IAA production and phosphate solubilization capacity. From eleven isolates obtained, one showed 99.77% homology with the type strain Streptomyces tricolor AS 4.1867, and was designated S. tricolor strain HM10. It showed aerial hyphae in SEM, growth inhibition of ten known phytopathogens in in vitro experiments, and the production of plant growth promoting compounds such as siderophores, IAA, and phosphate solubilization capacity. S. tricolor strain HM10 exhibited high antagonism against the fungi tested (i.e., Colletotrichum gloeosporides with an inhibition zone exceeding 18 mm), whereas the lowest antagonistic effect was against Alternaria solani (an inhibition zone equal to 8 mm). Furthermore, the most efficient siderophore production was recorded to strain HM8, followed by strain HM10 with 64 and 22.56 h/c (halo zone area/colony area), respectively. Concerning IAA production, Streptomyces strain HM10 was the most effective producer with a value of 273.02 µg/ml. An autochthonous strain S. tricolor HM10 should be an important biological agent to control phytopathogens and promote plant growth.

Genetic Diversity and Combining Ability of White Maize Inbred Lines under Different Plant Densities.

Knowledge of combining ability and genetic diversity are important prerequisites for the development of outstanding hybrids that are tolerant to high plant density. This work was carried out to assess general combining ability (GCA) and specific combining ability (SCA), identify promising hybrids, estimate genetic diversity among the inbred lines and correlate genetic distance to hybrid performance and SCA across different plant densities. A total of 28 F1 hybrids obtained by crossing eight adverse inbred lines (four local and four exotic) were evaluated under three plant densities 59,500 (D1), 71,400 (D2) and 83,300 (D3) plants ha-1 using spilt plot design with three replications at two locations during 2018 season. Increasing plant density from D1 to D3 significantly decreased leaf angle (LANG), chlorophyll content (CHLC), all ear characteristics and grain yield per plant (GYPP). Contrarily, days to silking (DTS), anthesis-silking interval (ASI), plant height (PLHT), ear height (EHT), and grain yield per hectare (GYPH) were significantly increased. Both additive and non-additive gene actions were involved in the inheritance of all the evaluated traits, but additive gene action was predominant for most traits. Inbred lines L1, L2, and L5 were the best general combiners for increasing grain yield and other desirable traits across research environments. Two hybrids L2 × L5 and L2 × L8 were found to be good specific combiners for ASI, LANG, GYPP and GYPH. Furthermore, these hybrids are ideal for further testing and promotion for commercialization under high plant density. Genetic distance (GD) among pairs of inbred lines ranged from 0.31 to 0.78, with an average of 0.61. Clustering based on molecular GD has effectively grouped the inbred lines according to their origin. No significant correlation was found between GD and both hybrid performance and SCA for grain yield and other traits and proved to be of no predictive value. Nevertheless, SCA could be used to predict the hybrid performance across all plant densities. Overall, this work presents useful information regarding the inheritance of maize grain yield and other important traits under high plant density.

Detoxification and reduction of selenite to elemental red selenium by Frankia.

Four Frankia strains (EuI1c, CN3, ACN14a and CcI3) were tested for selenite tolerance. Frankia inefficax strain EuI1c was resistant to selenite with a MIC value of 518.8 µg ml-1. After 48 h incubation with selenite, a reddish precipitate began to appear in these cultures. The red color suggests the reduction of the toxic, soluble, and colorless sodium selenite (Na2SeO32-) to the nontoxic, insoluble, and red colored elemental selenium (Seº). Analysis showed F. inefficax strain EuI1c cultures exposed to 17.3 and 86.5 µg ml-1selenite completely reduced all of the selenite after 5 and 8 days, respectively. When observed under Scanning Electron Microscopy, selenite-resistant F. inefficax strain EuI1c grown with selenite formed nanosphere particles on the hyphal surface as free deposits or in aggregates and inside the hyphae. EDAX analysis of the nanosphere particles determined that they are composed of selenium with up to 27.3-fold increase in intensity as compared to control cells. FTIR Spectroscopy of selenite-stressed cells showed cell surface changes in fatty acids, polysaccharides, carbohydrates and phosphate groups. This result suggests a mechanism for selenite reduction and nanosphere transport through cell membrane in this strain. Native gel electrophoresis of extracted cell-free protein revealed one band showing activity after staining with selenite and NADH. SDS-PAGE analysis revealed the presence of several bands with one dominant band of 37.8 kDa. Mass spectrometry analysis of the bands determined that the main proteins were a periplasmic-binding protein, sulfate ABC transporter and extracellular ligand-binding receptor.

Potato purple top disease associated with the novel subgroup 16SrII-X phytoplasma.

Potato (Solanum tuberosum) is a very economically important perennial tuberous crop in Saudi Arabia. Potato plants displaying symptoms associated with potato purple top disease, such as aerial tubers and purple and small leaves, were observed in Al-Bukairiyah, Fowlq and Buraydah, Al-Tarafiyah, Qassim governorate, Saudi Arabia. In this study, we examined samples taken from 12 symptomatic potato plants and confirmed the presence of phytoplasma DNA. Analysis of the 16S rRNA-encoding sequences revealed that the symptomatic plants were infected with phytoplasma belonging to the peanut witches'-broom group (16SrII). Sequencing of the 16S rRNA- encoding gene, computer-simulated RFLP analysis and phylogenetic analysis revealed the presence of a novel representative of the 16SrII-X subgroup. The present study identified potato plants as a novel host for novel phytoplasma strains belonging to the pigeon pea witches'-broom group in Saudi Arabia.

Evolution. Evolutionary resurrection of flagellar motility via rewiring of the nitrogen regulation system.

A central process in evolution is the recruitment of genes to regulatory networks. We engineered immotile strains of the bacterium Pseudomonas fluorescens that lack flagella due to deletion of the regulatory gene fleQ. Under strong selection for motility, these bacteria consistently regained flagella within 96 hours via a two-step evolutionary pathway. Step 1 mutations increase intracellular levels of phosphorylated NtrC, a distant homolog of FleQ, which begins to commandeer control of the fleQ regulon at the cost of disrupting nitrogen uptake and assimilation. Step 2 is a switch-of-function mutation that redirects NtrC away from nitrogen uptake and toward its novel function as a flagellar regulator. Our results demonstrate that natural selection can rapidly rewire regulatory networks in very few, repeatable mutational steps.

The biosurfactant viscosin produced by Pseudomonas fluorescens SBW25 aids spreading motility and plant growth promotion.

Food security depends on enhancing production and reducing loss to pests and pathogens. A promising alternative to agrochemicals is the use of plant growth-promoting rhizobacteria (PGPR), which are commonly associated with many, if not all, plant species. However, exploiting the benefits of PGPRs requires knowledge of bacterial function and an in-depth understanding of plant-bacteria associations. Motility is important for colonization efficiency and microbial fitness in the plant environment, but the mechanisms employed by bacteria on and around plants are not well understood. We describe and investigate an atypical mode of motility in Pseudomonas fluorescens SBW25 that was revealed only after flagellum production was eliminated by deletion of the master regulator fleQ. Our results suggest that this 'spidery spreading' is a type of surface motility. Transposon mutagenesis of SBW25ΔfleQ (SBW25Q) produced mutants, defective in viscosin production, and surface spreading was also abolished. Genetic analysis indicated growth-dependency, production of viscosin, and several potential regulatory and secretory systems involved in the spidery spreading phenotype. Moreover, viscosin both increases efficiency of surface spreading over the plant root and protects germinating seedlings in soil infected with the plant pathogen Pythium. Thus, viscosin could be a useful target for biotechnological development of plant growth promotion agents.

Production of anticandidal cotton textiles treated with oak gall extract / Producción de tejidos de algodón con actividad anticandidiásica tratados con extracto de agallas de roble

Candida albicans, one of the most dreadful fungal pathogens threatening humans, could not be easily prevented. The anticandidal activity of oak gall extract, Quercus infectoria (QIE), was investigated as a potential natural alternative to synthetic and chemical fungicides. QIE anticandidal potentiality was confirmed using both qualitative and quantitative assays. Cotton textiles were treated with QIE and then evaluated as anticandidal fabrics. QIE-treated textiles had a potent anticandidal activity, which could completely inhibit the inoculated C. albicans cells. The durability of anticandidal activity in QIE-treated textiles almost completely disappeared after the fourth laundering cycle. QIE could be recommended, however, as a potent anticandidal agent for preparing antiseptic solutions and emulsions and as a finishing agent for manufacturing anticandidal disposable diapers and hygienic clothes.

Candida albicans es uno de los patógenos fúngicos más terribles que amenazan la salud humana, y su prevención no resulta sencilla. En este trabajo se investigó la actividad anticandidiásica del extracto de agallas de roble (Quercus infectoria extract; QIE) como una posible alternativa natural a los fungicidas sintéticos y químicos. El potencial anticandidiásico del QIE se confirmó mediante análisis cualitativos y cuantitativos. Se trató tejido de algodón de uso textil con QIE y se lo evaluó como tela anticandidiásica. Se verificó que dichos tejidos exhibían una potente actividad anticandidiásica y que podían inhibir completamente a células de C. albicans inoculadas. La actividad anticandidiásica, sin embargo, desapareció por completo después del cuarto ciclo de lavado. Se concluye que se podría recomendar QIE como un agente anticandidiásico potente para la preparación de soluciones antisépticas y emulsiones, y como un agente de acabado para fabricar pañales desechables y ropa de higiene con propiedades anticandidiásicas.

Production of anticandidal cotton textiles treated with oak gall extract / Producción de tejidos de algodón con actividad anticandidiásica tratados con extracto de agallas de roble

Candida albicans, one of the most dreadful fungal pathogens threatening humans, could not be easily prevented. The anticandidal activity of oak gall extract, Quercus infectoria (QIE), was investigated as a potential natural alternative to synthetic and chemical fungicides. QIE anticandidal potentiality was confirmed using both qualitative and quantitative assays. Cotton textiles were treated with QIE and then evaluated as anticandidal fabrics. QIE-treated textiles had a potent anticandidal activity, which could completely inhibit the inoculated C. albicans cells. The durability of anticandidal activity in QIE-treated textiles almost completely disappeared after the fourth laundering cycle. QIE could be recommended, however, as a potent anticandidal agent for preparing antiseptic solutions and emulsions and as a finishing agent for manufacturing anticandidal disposable diapers and hygienic clothes.(AU)

Candida albicans es uno de los patógenos fúngicos más terribles que amenazan la salud humana, y su prevención no resulta sencilla. En este trabajo se investigó la actividad anticandidiásica del extracto de agallas de roble (Quercus infectoria extract; QIE) como una posible alternativa natural a los fungicidas sintéticos y químicos. El potencial anticandidiásico del QIE se confirmó mediante análisis cualitativos y cuantitativos. Se trató tejido de algodón de uso textil con QIE y se lo evaluó como tela anticandidiásica. Se verificó que dichos tejidos exhibían una potente actividad anticandidiásica y que podían inhibir completamente a células de C. albicans inoculadas. La actividad anticandidiásica, sin embargo, desapareció por completo después del cuarto ciclo de lavado. Se concluye que se podría recomendar QIE como un agente anticandidiásico potente para la preparación de soluciones antisépticas y emulsiones, y como un agente de acabado para fabricar pañales desechables y ropa de higiene con propiedades anticandidiásicas.(AU)

Botryticidal activity of nanosized silver-chitosan composite and its application for the control of gray mold in strawberry.

Botrytis cinerea Pers, the gray mold fungus, is among the most dangerous plant pathogens that cause great losses in agricultural crops. The botryticidal activities of nanosized silver (nano Ag), fungal chitosan (CTS) irradiated fungal chitosan (IrCTS), and nano Ag-IrCTS composite were investigated. All of the examined materials exhibited powerful antifungal activity against B. cinerea. The most effective compound was nano Ag-IrCTS composite with a minimal inhibitory concentration of 125 µg/mL. The microscopic examination, of treated B. cinerea with the composite, revealed that an obvious alteration in mycelial shape was appeared accompanied and moderate lysis in fungal hyphae. With the prolongation of treatment, most of the fungal mycelia were lysed into small and elastic fragments. The consequence of strawberries coating, with antifungal composite based solution, was the disappearance of gray mold infection signs in 90% of the contaminated fruits after 7 d of storage, treated fruits had a fresh-like appearance at the end of storage. Coating with nano Ag-IrCTS solution could be highly recommended regarding its efficiency in prohibiting B. cinerea growth, preventing gray mold decay and enhancing the overall quality of coated strawberry fruits.

Production of anticandidal cotton textiles treated with oak gall extract.

Candida albicans, one of the most dreadful fungal pathogens threatening humans, could not be easily prevented. The anticandidal activity of oak gall extract, Quercus infectoria (QIE), was investigated as a potential natural alternative to synthetic and chemical fungicides. QIE anticandidal potentiality was confirmed using both qualitative and quantitative assays. Cotton textiles were treated with QIE and then evaluated as anticandidal fabrics. QIE-treated textiles had a potent anticandidal activity, which could completely inhibit the inoculated C. albicans cells. The durability of anticandidal activity in QIE-treated textiles almost completely disappeared after the fourth laundering cycle. QIE could be recommended, however, as a potent anticandidal agent for preparing antiseptic solutions and emulsions and as a finishing agent for manufacturing anticandidal disposable diapers and hygienic clothes.

Production of anticandidal cotton textiles treated with oak gall extract. / Production of anticandidal cotton textiles treated with oak gall extract.

Candida albicans, one of the most dreadful fungal pathogens threatening humans, could not be easily prevented. The anticandidal activity of oak gall extract, Quercus infectoria (QIE), was investigated as a potential natural alternative to synthetic and chemical fungicides. QIE anticandidal potentiality was confirmed using both qualitative and quantitative assays. Cotton textiles were treated with QIE and then evaluated as anticandidal fabrics. QIE-treated textiles had a potent anticandidal activity, which could completely inhibit the inoculated C. albicans cells. The durability of anticandidal activity in QIE-treated textiles almost completely disappeared after the fourth laundering cycle. QIE could be recommended, however, as a potent anticandidal agent for preparing antiseptic solutions and emulsions and as a finishing agent for manufacturing anticandidal disposable diapers and hygienic clothes.