Impact of PGPR inoculation on growth and antioxidant status of wheat under saline conditions

Two plant growth‐promoting rhizobacterial (PGPR) strains, Bacillus subtilis SU47 and Arthrobacter sp. SU18, were found to tolerate 8% NaCl. Wheat co‐inoculated with these two PGPR strains, and grown under different salinity regimes (2–6 dS m^?1), showed an increase in dry biomass, total soluble sugars and proline content. Wheat sodium content was reduced under co‐inoculated conditions but not after single inoculation with either strain or in the control. The activity of antioxidant enzymes in wheat leaves decreased under salinity stress after PGPR co‐inoculation, suggesting these PGPR species could be used for amelioration of stress in wheat plants. Activity of three antioxidant enzymes in wheat grown with both PGPR strains was reduced, most notably that of catalase activity at a salinity of 6 dS m^?1, when compared with the control. The results indicate that co‐inoculation with B. subtilis and Arthrobacter sp. could alleviate the adverse effects of soil salinity on wheat growth.     

Seed priming with smoke water and karrikin improves germination and seedling vigor of Brassica napus under varying environmental conditions

Plant Growth Regulation - Environmental cues are major determinants in commercial cultivation of leafy vegetables, especially for resource-limited farmers. The aim of the study was to examine the...     

Impact of sugar beet seed priming on seed quality and performance under diversified environmental conditions of germination,emergence and growth

Journal of Plant Growth Regulation - In the presented work attempts have been made to explore effectiveness of the sugar beet (Beta vulgaris L.) seeds priming process in relation to seed quality...     

Pineapple stem-derived bromelain based priming improves pepper seed protein reserve mobilization,germination, emergence and plant growth

Pepper seeds are slow to germinate and emergence is often non-uniform and incomplete, reducing gains from this cash crop. This study investigated the effects of pineapple stem- derived protease (stem bromelain) based priming on pepper seed germination in relation to reserve mobilization (specifically, proteins and amino acids), germination, emergence and plant growth. These parameters were compared across two controls, (1) unsoaked seeds and (2) seeds soaked in deionized water, and seeds soaked in pineapple stem bromelain crude extract (treatment). Seeds were soaked in bromelain crude extract possessing a proteolytic activity of 6.25 tU or deionized water (first control) for 3 h at 35 °C. Light microscopy revealed an abundance of protein bodies in the endosperm of the seeds prior to imbibition. When observed for a period of 96 h, these bodies were progressively degraded, with the rate of this degradation being fastest in bromelain-treated seeds. Quantitative analysis of protein levels confirmed this observation: 17.2 mg proteins/g FW at 120 h after priming in bromelain-treated seeds compared with 22.1 mg/g FW in controls (average). The bromelain treatment also increased levels of free amino acids from 3.9 mg/g FW in the controls to 4.6 mg/g FW after 120 h of imbibition. Germination and emergence percentages were initially higher in bromelain-treated seeds: 92.0% germination in bromelain-treated seeds vs. ~ 52.2% in the controls at 18 d; 100% emergence in protease-treated seeds vs. ~ 72.2% in the controls at 18 d. However, these parameters were comparable across the treatment and the controls at 28 d. Importantly, plant fresh and dry weights were significantly higher when seeds were primed with bromelain. The results suggest the use of bromelain extracts for priming pepper seeds based on their proteolytic activity, since germination is dependent on the availability of crude protein and essential amino acids. The benefits of bromelain seed priming appear to translate into improved seedling growth as well.     

Seed priming with boron improves growth and yield of fine grain aromatic rice

Boron (B) is amongst the important micronutrients required for rice from start till physiological maturity. This study was conducted to explore the role of boron application in seedling emergence, leaf appearance and elongation, chlorophyll content, water relations and yield related traits of fine rice. Boron was applied as seed priming. For priming seeds of fine rice cultivars Super Basmati and Shaheen Basmati were soaked in 0.001 and 0.01?% aerated B solutions (w/v); while untreated dry seeds and water soaked (hydropriming) seeds were taken as control. Substantial improvement in seedling emergence was noted by seed priming in 0.001 and 0.01?% solutions. Rate of leaf emergence and elongation and tiller appearance were also improved in seedlings raised from seeds primed in 0.001?% B solution in the tested cultivars. Likewise, leaf chlorophyll contents were significantly improved by B especially with 0.001?% concentration; as was the case for water relations of rice cultivars. At final harvest, all yield contributing parameters were improved by B priming. Increase in yield was due to decrease in panicle sterility by B treatments. A linear increase in leaf and grain B contents was observed with increase in concentration of B priming solution. Overall, B application at very low rate substantially improved seedling emergence, leaf appearance and elongation, tillering, chlorophyll, water relations and yield related traits resulting in better yield and grain B contents. In this regard, seed priming offers an effective and pragmatic way of B application.     

Seed germination,seedling survival,and physiological response of sunflowers under saline and alkaline conditions

Salinization and alkalization of soil are widespread environmental problem and the alkali stress is more destructive than the effects caused by salt stress. To compare the mechanism of salt and alkali stresses, a sunflower variety (Helianthus annuus L. cv. Baikuiza 6) was tested under saline or alkaline conditions by mixing two neutral salts (NaCl and Na₂SO₄) or two alkaline salts (NaHCO₃ and Na₂CO₃). The results showed that saline conditions differed greatly from alkaline conditions in their threshold intensities where sunflower can germinate, survive and grow. Under saline conditions, the emergence time was delayed, and the emergence rate and seedling survival rate also decreased with increasing salinity. However, under alkaline conditions, the rate of seedling survival decreased sharply but the emergence time and emergence rate did not change. In addition, the damaging effects of alkali stress on growth and photosynthesis were more severe than those of saline. In shoots, the main inorganic osmolyte and cation was K⁺ rather than Na⁺; the primary organic osmolytes were organic acid and soluble sugar rather than proline. Organic acid, NO₃ ⁻, and Cl⁻ (only under saline condition) were the main source of anion. In addition, the osmotic adjustment and ion balance differed among sunflower roots, stems, and leaves. In conclusion, saline and alkaline conditions are two different stress conditions and there are special responses to two stress conditions for sunflower.     

Antibiofilm,antiproliferative, antioxidant and antimutagenic activities of an endophytic fungus Aspergillus fumigatus from Moringa oleifera

Molecular Biology Reports - An endophytic fungus Aspergillus fumigatus isolated from Moringa oleifera has been evaluated for its various bioactivities. The chloroformic fungal extract exhibited a...     

Molecular docking of phenolic compounds and screening of antioxidant and antidiabetic potential of Moringa oleifera ethanolic leaves extract from Qassim region,Saudi Arabia

IntroductionOxidative stress is crucial in diabetic pathophysiology, hence the prerequisite of ingesting naturally derived antioxidants as a remedial target. This study investigates the naturally occurring antioxidant and antidiabetic potential of Moringa oleifera ethanolic leaves extract.MethodsMoringa oleifera leaves were macerated (MOLE) by using 70% ethanol. Physiochemical and phytochemical examinations of MOLE was assayed using standard methods. The antioxidant activity was analyzed by DPPH (1, 1-diphenyl-2-picrylhydrazil) radical scavenging assay. In vitro antidiabetic was analyzed by pancreatic α-amylase enzyme inhibitory assay. The molecular docking was performed using AutoDock Vina v1.1.2 in PyRx 30.8.ResultsEthanolic extraction of MOLE by maceration technique, 14 % yield. Loss on drying, foreign organic matters and total ash value of OLE showed 0.27 w/w, 0.8 % and 19 %, respectively. Phytochemical test on MOLE confirmed starch, carbohydrate, flavonoid, gum, glycoside, saponin, tannin, and phenol presences. The total phenolic and flavonoid contents of MOLE are 260 mg GAE/g and 755 mg RUE/g of extract. MOLE (IC 50 55.6 ± 0.18 µg/mL) showed functional DPPH scavenging assay comparable to ascorbic acid (IC 50 46.71 ± 0.24 µg/mL). In the alpha-amylase inhibitory activity, Acarbose showed an IC 50 value of 19.45 ± 0.26 µg/mL, while MOLE portrayed an IC 50 value of 27.54 ± 0.07 µg/mL. Docking studies revealed that most phenolic compounds found within MOLE have minimum docking scores and high binding affinity against Human pancreatic alpha-amylase.ConclusionsThe invitro and docking results suggest that MOLE has been a viable natural bioactive source and might be a great potential source for future antidiabetic medicine.     

In vitro propagation and biosynthesis of steroidal sapogenins from various morphogenetic stages of Moringa oleifera Lam., and their antioxidant potential

Moringa oleifera is a highly valued medicinal plant. The present research reports callus cultures of M. oleifera Lam., established from seeds and nodal segments on Murashige and Skoog’s (MS) medium using different concentrations and combinations of auxins and cytokinins. Best induction of callus was observed at BAP:IBA (3 mg l^?1 each). Shooting and rooting from callus in terms of morphogenesis were observed in MS media supplemented with BAP:KN (2:0.2 mg l^?1) and IBA:NAA (3:0.5 mg l^?1), respectively. Multiple shooting was observed at treatment dose of BAP:NAA:IAA (1:1:0.2 mg l^?1). Regenerated shoots were rooted and mature plants were established, acclimatized, and thrived in greenhouse conditions. Over 95 % of plantlets survived after transplanting plantlets into trays with a mixture of sand and perlite (2:1) for 20 days. The regeneration protocol developed in this study provides a basis for germplasm conservation and for further investigation of bioactive constituents of this medicinal plant. Further qualitative and quantitative production of steroidal sapogenins (diosgenin and tigogenin) from various morphogenetic stages was studied using TLC, PTLC, IR spectra, HPLC and GC–MS analysis. Steroidal sapogenins were maximum in the callus associated with rooting. Various stages were further analyzed for their antioxidant potential.     

Expression of the citrus CsTIP2;1 gene improves tobacco plant growth,antioxidant capacity and physiological adaptation under stress conditions

Planta - Overexpression of the citrus CsTIP2;1 improves plant growth and tolerance to salt and drought stresses by enhancing cell expansion, H 2 O 2 detoxification and stomatal conductance....     

Alfin1 transcription factor overexpression enhances plant root growth under normal and saline conditions and improves salt tolerance in alfalfa

Plant root development is an essential determinant of plant growth and crop yield that could be enhanced by induced changes in the expression of root-specific regulatory factors. We reported previously that Alfin1 binds DNA in a sequence-specific manner and that Alfin1 overexpression in transgenic alfalfa (Medicago sativa L.) enhances expression of the salt-inducible MsPRP2 gene in roots, suggesting that Alfin1 functions to regulate gene expression in roots. Here we show that Alfin1 is an essential gene for root growth and that its overexpression in transgenic plants confers a many-fold increase in root growth under normal and saline conditions. Alfin1-binding sites occur in promoters of genes expressed in roots of a wide variety of plant species and we propose that it is a general root growth regulator. Even though Alfin1 overexpression was under the control of the CaMV 35S promoter, plant shoot growth was not adversely affected. We show further that introduction of the Alfin1 transgene in plants confers a dominant characteristic that significantly increases plant growth and salt tolerance.     

Aspirin priming circumvents the salinity-induced effects on wheat emergence and seedling growth by regulating starch metabolism and antioxidant enzyme activities

Though seed priming has been emerged as an effective and pragmatic approach, efforts are being made to discover and optimize the new priming agents which are cheaper and easily accessible to the farmers. Here, we established two independent experiments, to ascertain the role of aspirin priming in salinity tolerance of wheat. In the first experiment, various concentrations of aspirin (125, 250, 375, and 500 ppm) were examined for emergence and seedling growth of wheat. A non-primed control, hydropriming, and hydrogen peroxide priming treatments were also maintained for comparison. Among the different treatments, seeds primed with 125 and 250 ppm aspirin depicted better emergence, vigorous seedling growth, and higher starch metabolism. Therefore, these treatments were further used in the second experiment under salinity stress (10 dS m^?1). Salinity stress caused delayed and erratic emergence hampered the shoot and root growth, chlorophyll contents, and enhanced the lipid peroxidation and phenolics content in wheat seedlings. However, wheat seed priming particularly with aspirin effectively alleviated the negative effects of salinity on most of the observed parameters. Aspirin priming also significantly enhanced the activities of antioxidant enzymes (catalase, peroxidase, and superoxide dismutase), and reduced oxidative stress in wheat seedlings. Vigorous growth and greater salinity tolerance of wheat seedlings derived from aspirin primed seeds were related with better starch metabolism, strong antioxidative defense system, and lower lipid peroxidation.     

The antioxidant properties and microbial load of Moringa oleifera leaves dried using a prototype convective air-dryer

The recent COVID-19 pandemic resulted in major postharvest losses because most fresh produce could not be sold. Drying is an important thermal-based food preservation method which could have prolonged the shelf-life of these produce, but most drying technologies are costly, and cannot be afforded by small-time farmers. From this context, we were interested in evaluating the drying of Moringa oleifera leaves (MOL) using a low-cost self-built prototype convective-air dryer (CAD), alongside conventional drying methods for its antioxidant properties, microbial load and phytoconstituents. Results showed total polyphenol content was the highest (p < 0.05) in our CAD samples, and it retained among the highest total flavonoid content, total antioxidant capacity, total alkaloid content and DPPH radical scavenging activity. Furthermore, methanolic CAD extract presented lower coliform and yeast and mold count than the aqueous CAD extract. We also briefly explored MOL as a sanitizer where the microbial load of the methanolic extract was comparable (p > 0.05) with several commercial non-alcoholic sanitizers, indicating its commercialization potential as a bio-friendly sanitizer. Finally, using GC–MS, we are the first to report (best of our knowledge) on the presence of caprolactam, an important bio-medical field compound, in the CAD sample’s aqueous extract.     

水氮耦合对辣木生长特性的影响

辣木(Moringa oleifera)具有重要的经济价值.土壤水分及氮素有效性对辣木生长具有显著影响.以辣木'PKM I'品种为研究材料,于华南农业大学资源环境学院生态学教学实验基地温室内进行盆栽试验,试验设置3个水分:分别为田间饱和持水量的40％(W1)、60％(W2)、80％(W3),以及4个氮水平:0 g ?株...     

Elongation growth in leaf blades of Chloris gayana under saline conditions

In Chloris gayana, salinity-associated yield decreases are due mainly to leaf area reductions. To understand the physiological basis for such reduction, the effects of salinity were studied on the spatial and temporal distribution of extension in the intercalary meristem at the leaf base, and on hydraulic conductance in that zone. C. gayana plants were grown on sand irrigated with Hoagland solution with the addition of 0 or 200 mmol/L NaCl, and all measurements were performed on tiller leaf four. In salinised plants, that leaf was 20% shorter than in controls. Extension in the blade expansion zone was studied by pricking through the leaf sheaths and analysing the displacement of the pricks. In salt-treated plants, maximum growth rates were depressed by 53% and the growth zone was shorter by approximately 10 mm, nevertheless, extension proceeded for a longer period than in control plants. The analysis of specific leaf areas in the expansion zone suggests the rate of dry matter deposition was lowered by salinity and estimations of tissue displacement time within that zone suggest cell wall maturity was delayed. Hydraulic conductance was reduced by salinity and this may be the main cause for reduced growth under salinity in Chloris gayana.     

Evaluation of the effects of Chlorella vulgaris,Nannochloropsis salina,and Enterobacter cloacae on growth,yield and active compound compositions of Moringa oleifera under salinity stress

Application of Chlorella vulgaris, Nannochloropsis salina and Enterobacter cloacae has been reported to improve the growth of multiple plant species. Moringa oleifera is a medicinal plant found in Saudi Arabia. Its leaves, flowers and fruit have been used as food. Moringa oleifera is rich in rutin and gallic acid and many other bioactive compounds, which collectively contribute to its demonstrated range of pharmacological activities. In Saudi Arabia, the semi-arid and arid weather presents a significant challenge to agriculture. High salinity in cultivated land is a particular threat. We applied Chlorella vulgaris, Nannochloropsis salina, and Enterobacter cloacae at multiple salinities to Moringa oleifera to investigate their effects on the growth, yield, and photosynthetic pigment content. We also examined possible changes in the phytochemical composition. The application of Chlorella vulgaris, Nannochloropsis salina and Enterobacter cloacae enhanced plant growth and yield, while inhibition was observed at high (6000 ppm) salinity. The presence of Chlorella vulgaris and Nannochloropsis salina altered plant growth and yield and rutin and gallic acid content of Moringa oleifera plants grown in saline conditions. Microalgae species were recommended for use as a bio-fertiliser alternative to mainstream synthetic fertilisers.     

Comparative study among Avicennia marina,Phragmites australis,and Moringa oleifera based ethanolic-extracts for their antimicrobial,antioxidant, and cytotoxic activities

Microbial resistance and other emerging health risk problems related to the side effects of synthetic drugs are the major factors that result in the research regarding natural products. Fruits, leaves, seeds, and oils-based phyto-constituents are the most important source of pharmaceutical products. Plant extract chemistry depends largely on species, plant components, solvent utilized, and extraction technique. This study was aimed to compare the ethanolic extracts of a mangrove plant, i.e., Avicennia marina (1E: Lower half of A. marina‘s pneumatophores, 2E: A. marina‘s leaves, 3E: Upper half of A. marina‘s pneumatophores, and 4E: A. marina‘s shoots), with non-mangrove plants, i.e., Phragmites australis (5E: P. australis‘s shoot), and Moringa oleifera (6E: M. oleifera‘s leaves) for their antimicrobial activities, total phenolic contents, antioxidant activity, and cytotoxicity potential. The antimicrobial activity assays were performed on gram-positive bacteria (i.e., Bacillus subtilis and Staphylococcus aureus), gram-negative bacteria (i.e., Escherichia coli, and Pseudomonas aeruginosa), and fungi (i.e., Aspergillus niger, Candida albicans, and Rhizopus spp.). We estimated antioxidant activity by TAC, DPPH, and FRAP assays, and the cytotoxicity was evaluated by MTT assay. The results of antimicrobial activities revealed that B. subtilis was the most sensitive to the tested plant extracts compared to S. aureus, while it only showed sensitivity to 6E and Imipenem. 5E and 6E showed statistically similar results against P. aeruginosa as compared to Ceftazidime. E. coli was the most resistant bacteria against tested plant extracts. Among the tested plant extracts, maximum inhibition activity was observed by 6E against A. niger (22 ± 0.57 mm), which was statistically similar to the response of 6E against C. albicans and 3E against Rhizopus spp. 2E did not show any activity against tested fungi. We found that 6E (208.54 ± 1.92 mg g^?1) contains maximum phenolic contents followed by 1E (159.42 ± 3.22 mg g^?1), 5E (131.08 ± 3.10 mg g^?1), 4E (i.e., 72.41 ± 2.96 mg g^?1), 3E (67.41 ± 1.68 mg g^?1), and 2E (48.72 ± 1.71 mg g^?1). The results depict a significant positive correlation between the phenolic contents and the antioxidant activities. As a result, phenolic content may be a natural antioxidant source.     

A preliminary study on the absorption of phosphate and growth of plant under saline conditions

Summary Tomato plants were grown in sand cultures receiving various rates of phosphate fertilization along with different levels of sodium in order to investigate the uptake of phosphorus under saline conditions.Sodium as well as phosphorus was found to have a favourable influence on the yield of plant during the whole studied growth period. However, increassing the concentration of sodium above certain limits resulted in an opposite effect.Absorption of phosphate followed a similar trend to that of plant yield. However, the so-called Phosphate Utilization Quotient followed a relatively different trend. It was generally decreased with raising the level of applied phosphorus in the growth media of plants under all treatments tested. On the other hand, the indicated quotient was generally increased with increasing the application rates of sodium element.