Arbuscular Mycorrhizal Fungi Enhance Sorghum Plant Growth under Nitrogen-Deficient Conditions through Activation of Nitrogen and Carbon Metabolism Enzymes

Nitrogen (N), one of the most important elements for plant growth, is needed by plants in large quantities. However, this nutrient has limited supply in the soil. Arbuscular mycorrhizal fungi (AMF) are known for their ability to form symbiotic association with plants and transfer the mineral nutrients to the host plants. To validate this hypothesis on sorghum plants, three ecotypes of this cereal (3p4, 3p9 and 4p11) were cultivated with and without AMF under low nitrogen concentration (0.5 mM NH4+). Growth parameters were determined and key enzymes responsible for nitrogen and carbon metabolisms such as glutamine synthetase (GS), glutamate dehydrogenase (GDH), phosphoenolpyruvate carboxylase (PEPC), isocitrate dehydrogenase (ICDH), malate dehydrogenase (MDH) and asparate aminotransferase (AAT) were measured. For the three sorghum ecotypes, mycorrhizal plants showed a higher plant growth compared to the control plants. The biochemical parameters revealed a significant increase in the nitrogen assimilatory enzymes; GS and GDH in the leaves and roots of mycorrhizal plants. Furthermore, mycorrhizal fungi also appear to have a significant effect on carbon assimilatory enzymes. These enzymes are known to have a cardinal role in the provision of carbon skeletons essential for the assimilation of ammonium and thus, amino acids synthesis. Our study indicates clearly that AMF can be an efficient way to optimize nitrogen uptake and/or assimilation by plants and thus improve the crop yields with lower amount of nitrogen fertilizers. © 2021 Friends Science Publishers

Antidiabetic, Antibacterial and Antioxidant Potential of Bioactive Peptides Extracted from the Germinated Seeds of Poncirus trifoliata

The seeds proteins are converted into the peptides during the germination through peptidases. These bioactive peptides are fractionated through the enzymes. The bioactive peptides are reported with the number of therapeutic effects like antioxidant, antibacterial, antidiabetic, anti-cancerous and antihypertensive etc. Synthetic drugs have number of adverse effects along with the therapeutic effects, but natural sources are safer and free from this problem. In the present research, Poncirus trifoliata seedling peptides extracts were used to determine antibacterial, antioxidant and anti-diabetic activities. The peptides extract showed substantial growth of inhibition against pathogenic strains including Escherichia coli, Staphylococcus aureus and Bacillus subtilis having the superior effect as compared to amoxicillin antibiotic as a standard drug. The IC50 value of P. trifoliata seeds peptides extract was 32.91 μg mL-1 as compared with standard (IC50) value 25.52 μg mL-1 of ascorbic acid showed good potential as antioxidant activity. The extracted germinated seeds peptides showed considerable antidiabetic activity in controlling the blood glucose level of alloxan induced diabetic rabbits to compare with standard drugs like glibenclamide. Thus, this study confirmed the antibacterial, antioxidant and antidiabetic effects of P. trifoliata seeds peptides is significantly higher as compared to pure drugs. Therefore, further complete separation and detailed investigation study is needed to isolate target peptides and revealed mechanism of action of bioactive peptides and formulation as a drug to replace the synthetics drugs with safe one. © 2021 Friends Science Publishers

Molecular and Phenotypic Analysis of Bread Wheat Varieties in Relation to Durable Rust Resistance

Global wheat production is constantly threatened by rust diseases. Identifying resistant genes is a useful tactic to control wheat rust pathogen. Twenty-six wheat varieties were screened with twelve Simple Sequence Repeats (SSR) markers to detect rust resistant genes and the efficacy of genes was validated through field testing. The alleles Lr32, Lr39, Lr50, SrCad and SrWeb were not amplified in the varieties included in this study. The SSR markers indicated that the varieties viz., Chakwal-97, Bakhar-2002 and Lasani-2008 had a combination of 02 slow rusting alleles (Lr46/Yr29 and Yr18/Lr34). The adult plant resistance (APR) allele Yr17 was less prevalent and found only in BWL-97. However, Noshera-96 had a slow rusting combination of Lr67/Yr46 and Lr46/Yr46 alleles. The Lr46/Yr29 identified in 50% of the varieties, Yr18/Lr34 in 19.23%, Lr32 in 11.54%, and multiple APR alleles in 19.32%. Their resistance was validated through a field trap nursery for 3 consecutive seasons. The slow rusting combination of Lr46/Yr29 and Yr18/Lr34 was comparatively more effective than Lr67/Yr46 and Lr46/Yr29 alleles under field conditions. The varieties Yecora-70, Lylpure-73 and Tandojam-83 showed highly susceptible phenotype. The varieties Chakwal-86, Pirsabak-2005, Fareed-2006, and Sehar-2006 showed resistant to moderately resistant phenotype at high-temperature adult-plant stage. The cluster diagram divided the varieties into two distinct clades. The clade II depicted the abundance of APR allele Lr46/Yr29. The varieties contain valuable sources of durable rust resistant alleles that can be exploited to deploy rust resistance in future wheat cultivars. It has been observed that the varieties approved for commercial cultivation after 1990s and onwards contain APR alleles. © 2021 Friends Science Publishers

Co-Application of Farmyard Manure and Gypsum Improves Yield and Quality of Peanut (Arachis hypogaea) under Rainfed Conditions

Peanut (Arachis hypogaea L.) is the common cash crop of the rainfed areas. Appropriate management practices are very important to get better yield of peanut in sandy loam soil. A field study was carried out during the growing seasons of 2018 and 2019 to evaluate the effect of poultry manure (PM) (37.1 t ha-1), farmyard manure (FYM) (49.4 t ha-1), gypsum (GYP) (2.5 t ha-1), liquid humic acid (HA) (49.4 L ha-1) and co-application of GYP (1.2 t ha-1) and FYM (24.7 t ha-1) on peanut yield, quality and soil physical properties. Application of FYM, PM, HA and GYP (alone or in combination) significantly improved peanut yield, quality and soil physical properties. The combined application of GYP and FYM proved most effective (P ≤ 0.05) in improving the peanut yield (no. of pods per plant, 100 seed weight etc), quality (crude protein and oil content) and soil physical properties (moisture percentage, infiltration rate and bulk density). The combined application of GYP and FYM increased the pods yield by 67 and 65% during 2018 and 2019, respectively than control. Crude proteins (21%) and oil contents (9.0%) were also substantially increased in the combined application. Moreover, the combined application of GYP and FYM significantly retained the soil moisture and reduced bulk density of soil. Present findings suggest that integrated use of FYM and GYP under field conditions could improve the crop productivity, crude protein, oil contents, moisture percentage, and reduce the bulk density of soil thus improving overall soil health. © 2021 Friends Science Publishers

Enhancement of Cellulose Rich Organic Matter Degradation by Inoculation with Streptomyces sp. Strains

Microbial degradation of organic matter is a vital part of carbon cycle in nature. Actinobacteria play an important role in the decomposition of cellulose rich organic matter (CROM). Streptomyces spp. are abundant in soil, produce various secondary metabolites and secrete extracellular enzymes. The aim of this research was to isolate and select Streptomyces strains with the best cellulose degradation abilities. Out of total 32 actinobacteria isolates, four Streptomyces strains (CA1, CA10, PA2 and PA7) were subjected to morphological, physiological, biochemical characterization and molecular identification. CROM degradation potential of the strains was investigated on straw and beech briquettes as well as on legume based substrate in in vitro condition. Streptomyces strains CA1 and CA10 showed the best cellulose production and starch hydrolysis abilities, followed by strains PA2 and PA7. Strain CA1 was also positive to production of pectinase enzymes. Streptomyces zaomyceticus CA1 and S. tanashiensis CA10 were used as inoculants, which degraded the raw cellulose from 38.38 to 81.69% in the investigated substrates (straw, beech, legume), during a 30-day incubation experiment. CROM inoculation with the selected Streptomyces strains improved and accelerated its degradation in controlled conditions. © 2021 Friends Science Publishers

Phenotypic Antimicrobial Resistance Patterns in Salmonella typhimurium and Enteritidis Strains Isolated from Human, Food, and Environmental Samples of Broiler Meat Production Chain in Punjab

The emergence of antimicrobial resistance is a growing public health issue worldwide due to extensive use in agriculture, food, and veterinary medicine. The rate of antimicrobial resistance varies with different antibiotics and serotypes but Salmonella enterica serovar Enteritidis is one of the most widespread serotypes which is comparatively more susceptible to antimicrobial resistance followed by S. Typhimurium. A total of 71 Salmonella strains (S. Typhimurium, n=45; S. Enteritidis, n=26) isolated from humans, food and the environment were used in the study. Both isolates were confirmed through PCR by targeting their specific spy and sdf genes respectively. Kirby-Bauer disc diffusion method was used to determine antimicrobial susceptibility against 10 antibiotics used. An exponentially high level of resistance was found in S. Typhimurium strains. The highest level of resistance was found against amoxicillin (97.78%) followed by tetracycline (95.56%), gentamicin (93.33%), trimethoprim (86.67%), streptomycin (84.44%), nalidixic acid (77.78%), sulphafurazole (64.44%), ampicillin (62.22%), chloramphenicol (46.67%) and least resistance was found against ciprofloxacin (31.11%). Four penta MDR (ACSSuT) and two tetra MDR (ASSuT) resistance patterns were found S. Typhimurium strains. In S. Enteritidis strains, a high level of resistance was found against sulphonamides and streptomycin (92.31%) with the least resistance against ciprofloxacin (11.54%). Two penta MDR (ACSSuT) and six tetra MDR (ASSuT) resistance patterns were found. The presence of high antimicrobial resistance in zoonotic S. Typhimurium and Enteritidis in the broiler meat production chain is alarming. Immediate action and appropriate measures are required to control over the counter and irrational use of antibiotics both in poultry and humans. © 2021 Friends Science Publishers

Evaluation of Antagonistic Bacillus and Biochar against Soybean Root Rot Caused by Fusarium oxysporum

Soybean root rot is a worldwide soil-borne fungal disease threatening soybean production, causing huge losses in yield and quality of soybean. Fusarium species are well recognized as the important causal agent of Fusarium root rot. To screen the beneficial Bacillus strains with capability of suppressing soybean root rot and evaluate the impact of Bacillus combined with biochar against soybean root rot, a pot experiment was conducted with different treatments. In this study, as potential biological control measures, antagonistic Bacillus isolates and different types of biochar were added to soil separately and excellent antagonistic strains mixed with bamboo biochar were applied to the soil. The results showed that seven Bacillus strains promoted the growth of soybean seedlings and reduced root rot severity by 33 to 61%. Bacillus amylolique faciens NH2 was associated with the lowest incidence of soybean root rot, indicating its bio-control potential. The value of plant height, root length and plant dry weight of soybean in the sterilized soil mixed with biochar separately treatment were superior to those of soybean in the inoculated with pathogen treatment, especially the bamboo biochar treatment reduced soybean root rot caused by Fusarium significantly and which bio-control efficacy was 77.41%. The soybean plants shoot and root dry weights in the biochar mixed B. amylolique faciens NH2 or B. subtilis DBK treatments were increased by17.1, 10.7% and 19.51, 19.64%, respectively, which were significantly higher than those of the inoculated pathogen treatment. Compared to antagonistic strain or biochar individual treatments, the disease control efficiency on soybean root rot was up to 64.86% in NH2 strain mixed with bamboo biochar treatment, which reduced root rot severity significantly and showed a synergistic effect. These results suggest that antagonistic Bacillus strains mixed with biochar can be used as an effective alternative in managing soybean root rot. © 2021 Friends Science Publishers

Screening of Bacteria for Biosurfactants, Exopolysaccharides and Biofilms and their Impact on Growth Stimulation of Zea mays Grown under Petrol Stress

Environmental stress imposed by petroleum hydrocarbons can compensate by use of auxin-producing bacteria having potential for biosurfactants production, to assist improved plants’ growth in petrol contaminated areas. In the present work, four auxin-producing bacteria were screened for biosurfactants, exopolysaccharides (EPS) and biofilms production capability. We hypothesized that Enterobacter sp. (A5C) was the most efficient strain with respect to biosurfactant production and can accumulate EPS as well as biofilms. This strain was attributed to exhibit emulsification index, percentage of hydrophobicity and percentage of hydrocarbon degradation more than 50%. Also, it produced 9.27 mg of EPS per 100 mL of culture while Fourier transform infrared spectroscopy (FTIR) confirmed the presence of alcoholic and carboxylic groups, ketone and sugars in it. Results of in vitro plant microbe interaction assay revealed its potential to stimulate the growth of Zea mays L. plants under 1 and 2% of petrol stress by improving physio-chemical attributes of treated plants, over control. Thus, it is concluded that the test organism i.e., Enterobacter sp. (A5C) might be involved in developing bacterial community (EPS and biofilms) that helped to colonize the bacteria to the plant roots and soil particles that ultimately encouraged the more access to nutrients and protection of plant roots from toxins in soil ecosystem. © 2021 Friends Science Publishers

Do Hydro-Retainer Polymers Attenuate Damage from Water Fluctuations in Leaf Metabolism and the Quality of Cedrela odorata Seedlings?

Water stress, caused by excess or lower of water, can negatively affect leaf metabolism and seedling growth and prevent it from developing its maximum genetic potential. In this sense, it is necessary to use as that can mitigate these deleterious effects on plants at their initial phase of growth. The aim of this work was to evaluate the effect of hydrogel in the mitigation of water stress (deficit and flooding) on photosynthetic metabolism and growth characteristics of C. odorata seedlings, and also evaluate their recovery potential after the resumption of irrigation. The characteristics of photosynthetic metabolism, growth and quality of C. odorata seedlings showed a reduction caused by water fluctuations, indicating sensitivity to these conditions, although photosynthesis photochemistry was affected to a lower extent. The addition of the hydro-retainer polymer contributed little to the biochemical and photochemical indicators of photosynthesis and seedling quality, a fact that directs us to reject our hypothesis that its use promotes mitigation of damage to the photosynthetic apparatus and to the growth. Cedrela odorata is sensitive to water variations in the soil, but recovers the photosynthetic metabolism and quality of the seedlings once the stressful water condition is suspended. The application of the hydro-retainer polymer mitigated, but the seedlings recovered regardless of their presence. © 2021 Friends Science Publishers

Impact of Seed Treatments with Fungal Biocontrol Agents on Enzymatic Activities and Phenolic Content of Soybean under Greenhouse and Field Conditions

Fungi in the genus Trichoderma are widely used as biological control agents because they can suppress plant pathogens and activate plant defense systems. In the present study, efficacy of microbial antagonists viz., T. harzianum and T. viride or their combination was evaluated against the pathogenic fungus Macrophomina phaseolina and their effect on enzymatic activities and phenol content of soybean [Glycine max (L.) Merr.] plants. Soybean seeds were inoculated with T. harzianum and T. viride separately or in combination, and sown in pots under green house and under field conditions. Host enzymatic activities and phenol levels were measured at 14, 28 and 42 days after sowing (DAS) in both field and greenhouse experiments. Seed treatments with T. harzianum, T. viride or their combination increased peroxidase, polyphenol oxidase and β-1, 3-glucanase activities, and also the total phenol content in soybean leaves as compared to a non-treated control treatment. Concentration of peroxidase and β-1, 3-glucanasepeaked at 14 DAS and decreased thereafter in all the treatments under greenhouse and field conditions. All the treatments showed the highest levels of total phenols and polyphenol-oxidase at 28 DAS under both greenhouse and field conditions. At 14 DAS in both trials, the combination of T. viride + T. harzianum resulted in the highest level of peroxidase and β-1, 3-glucanase activities. This combination also resulted in the highest levels of total phenols and polyphenol oxidase content at 28 DAS. Our findings demonstrated that application of Trichoderma species as seed treatment has potential to trigger key mechanisms of systemically acquired resistance in soybean, and thereby enhanced efficacy of disease management tactics. © 2021 Friends Science Publishers