Potential Use of Ascophyllum nodosum as a Biostimulant for Improving the Growth Performance of Vigna aconitifolia (Jacq.) Marechal.

The fertilizers that are derived from seaweed are known as Seaweed Liquid Fertilizers (SLF). SLF is a modern, cheap, non-toxic, and natural bioactive fertilizer. Among different studied seaweeds, Ascophyllum nodosum is significant as having bioactive ingredients that potentially regulate the molecular, physiological, and biochemical processes of crop plants. In the present study, the effects of the application of different concentrations (0.00%, 0.01%, 0.02%, 0.05%, 0.10%, 0.50%, and 1.00%) of A. nodosum Extract (ANE) to the Vigna aconitifolia through roots (Pot Root Application, PRA) and on the leaves (Pot Foliar Application, PFA) were monitored via the plant growth. The lower concentrations of ANE in both the PRA and PFA experiments showed positive growth on V. aconitifolia. The 0.10% ANE stimulated the maximum shoot growth when applied through the roots, while 0.05% ANE in both PFA and PRA experiments led to an increase in the number of pods, nodules, organic content, and moisture percentage. The 0.10% ANE also increased the leaf numbers, leaf area, and photosynthetic pigments. Hence, the application of 0.05% and 0.10% of A. nodosum extract in two ways (i.e., Pot Foliar Application, PFA, and Pot Root Application, PRA) ameliorated the growth capabilities of V. aconitifolia.

Silver Nanoparticles Biosynthesis, Characterization, Antimicrobial Activities, Applications, Cytotoxicity and Safety Issues: An Updated Review.

Rapid advances in nanotechnology have led to its emergence as a tool for the development of green synthesized noble metal nanoparticles, especially silver nanoparticles (AgNPs), for applications in diverse fields such as human health, the environment and industry. The importance of AgNPs is because of their unique physicochemical and antimicrobial properties, with a myriad of activities that are applicable in various fields, including the pharmaceutical industry. Countries with high biodiversity require the collection and transformation of information about biological assets into processes, associations, methods and tools that must be combined with the sustainable utilization of biological diversity. Therefore, this review paper discusses the applicable studies of the biosynthesis of AgNPs and their antimicrobial activities towards microorganisms in different areas viz. medicine and agriculture. The confirmed antiviral properties of AgNPs promote their applicability for SARS-CoV-2 treatment, based on assimilating the virus' activities with those of similar viruses via in vivo studies. In this review, an insight into the cytotoxicity and safety issues of AgNPs, along with their future prospects, is also provided.

The Effect of Ascophyllum nodosum Extract on the Nutraceutical Antioxidant Potential of Vigna radiata Sprout under Salt Stress.

Mung bean (Vigna radiata L.) sprout is a popular fresh vegetable, tasty and high in antioxidants. To increase yield and quality after the occurrence of both abiotic and biotic stresses, the application of seaweed extracts is of great importance. Hence, this study was conducted to determine the effect of Ascophyllum nodosum extract (ANE) in the presence of salt on the antioxidant potential of V. radiata sprouts. Different concentrations of ANE viz. 0.00, 0.01, 0.05, 0.10, and 0.50% and NaCl 0, 25, 50, 75, and 100 mM alone and in combinations were tested for researching the antioxidant potential of V. radiata sprouts at 0, 24, and 36 h of sprouting. The DPPH free-radical-scavenging activity of sprouts of V. radiata was found to increase with time and peaked at 24 h of treatment. The A. nodosum extract (0.01%) could reverse the ill effect of the low level of salinity posed by up to 25 mM NaCl. The increasing salinity deteriorated the antioxidant activity using ABTS method of sprouts down to 20.45% of the control at 100 mM NaCl. The total phenolic content (TPC), total flavonoid content (TFC), and reducing power of V. radiata sprouts was found to increase till 36 h of sprouting. A slight increase in TPC, TFC and reducing power was observed when seeds were treated with low concentrations of ANE. The elevation in TPC, TFC and reducing power upon treatment with low concentrations of ANE was also noticed in sprouts in saline combinations. Alpha amylase inhibition activity was found to reach a (67.16% ± 0.9) maximum at 24 h of sprouting at a 0.01% concentration of ANE. Tyrosinase inhibition and alpha glucosidase inhibition was 88.0% ± 2.11 and 84.92% ± 1.2 at 36 h of sprouting, respectively, at 0.01% concentration of ANE. A. nodosum extract is natural, environmentally friendly, and safe, and could be used as one of the strategies to decline stress at a low level and enhance the antioxidant activities in V. radiata sprouts, thus increasing its potential to be developed as an antioxidant-based functional food.

Characterization of heat resistant mutant strains of Rhizobium sp. [Cajanus] for growth, survival and symbiotic properties.

Fourteen heat resistant mutant strains were isolated from a wild-type strain (PP201, Nod(+) Fix(+)) of Rhizobium sp. (Cajanus) by giving it a heat shock of 43°C. These mutant strains showed a greater increase in optical density (O.D.) and a higher viable cell count in both rhizospheric and non-rhizospheric soil at high temperature. Symbiotic studies showed that pigeon pea plants inoculated with a few mutant strains had ineffective nodules (Nod(+) Fix(-)) under controlled temperature (43°C) conditions, but under natural high temperature (40-45°C) conditions, the host plants infected with all the mutant strains showed higher total shoot nitrogen than the plants inoculated with the parent strain. Four mutant strains (HR-3, HR-6, HR-10 and HR-12) were found to be highly efficient for all the symbiotic parameters, and thus have the potential to be used as bioinoculants in the North-Western regions of India during the summer season.

High temperature-induced changes in exopolysaccharides, lipopolysaccharides and protein profile of heat-resistant mutants of Rhizobium sp. (Cajanus).

A thermosensitive wild-type strain (PP201) of Rhizobium sp. (Cajanus) and its 14 heat-resistant mutants were characterized biochemically with regard to their cell surface (exopolysaccharides (EPSs) and lipopolysaccharides (LPSs)) properties and protein profile. Differences were observed between the parent strain and the mutants in all these parameters under high temperature conditions. At normal temperature (30 degrees C), only half of the mutant strains produced higher amounts of EPSs than the parent strain, but at 43 degrees C, all the mutants produced higher quantities of EPS. The LPS electrophoretic pattern of the parent strain PP201 and the heat-resistant mutants was almost identical at 30 degrees C. At 43 degrees C, the parent strain did not produce LPS but the mutants produced both kinds of LPSs. The protein electrophoretic pattern showed that the parent strain PP201 formed very few proteins at high temperature, whereas the mutants formed additional new proteins. A heat shock protein (Hsp) of 63-74 kDa was overproduced in all mutant strains.