Induction of high frequency somatic embryogenesis and analysis of developmental stagewise expression of <em>SERK1</em> gene during somatic embryogenesis in cultures of <em>Vigna radiata</em> (L.) R.Wilczek

180-193Vigna radiata (L.) R.Wilczek (Fabaceae), commonly called Green gram or Mung bean, is an important legume with potential nutritional, medicinal and health benefits cultivated widespread throughout the rain-fed areas of arid and semi-arid tropics and subtropics. Being an affordable source of carbohydrate, vitamins, minerals and phytonutrients besides protein, Green gram finds demand for its nutrient digestibility, food processing properties and bioavailability. Though India ranks top in world mung bean production (>50%), it is unable to meet the local demand. Biotic and abiotic stresses restrict mung bean yield considerably and researchers have been working on resistant varieties to overcome these challenges. In this study, towards improving yield, an effective protocol for attaining high frequency somatic embryogenesis (SE) in green gram has been proposed. Type of explants and age of source seedlings for obtaining explants were found to influence the formation of embryogenic calli. Various combinations and concentrations of 2,4-dichlorophenoxyacetic acid and indole-3-acetic acid with kinetin were optimized for developing embryogenic calli. Embryogenic calli when exposed to osmotic stress created by D-mannitol and sorbitol and dehydration stress imposed by polyethylene glycol were found to produce somatic embryos. Calli incubated for 6 h in specified hormone free nutrient medium supplemented with 4% polyethylene glycol was optimal for induction of high frequency SE. Subsequent to stress incubation, the cultures formed only early stage somatic embryos. Supplementation of proline was found essential for the maturation of somatic embryos. Cotyledonary stage somatic embryos were converted into plantlets and subsequently established in garden soil. Semi-quantitative Reverse Transcription-PCR based transcript level analysis of SERK1 gene expression was carried out during different developmental stages of somatic embryogenesis. Expression of SERK1 was specifically associated with the embryogenic calli and calli enriched with globular stage somatic embryos

A microdroplet cell culture based high frequency somatic embryogenesis system for pigeonpea, <i style="mso-bidi-font-style:normal">Cajanus cajan</i> (L.) Millsp.

600-610A protocol for high frequency production of somatic embryos was worked out in pigeonpea, Cajanus <i style="mso-bidi-font-style: normal">cajan (L.) Millsp. The protocol involved sequential employment of embryogenic callus cultures, low density cell suspension cultures and a novel microdroplet cell culture system. The microdroplet cell cultures involved culture of a single cell in 10 µl of Murashige and Skoog’s medium supplemented with phytohormones, growth factors and phospholipid precursors. By employing the microdroplet cell cultures, single cells in isolation were grown into cell clones which developed somatic embryos. Further, 2,4-dichlorophenoxyacetic acid, kinetin, polyethylene glycol, putrescine, spermine, spermidine, choline chloride, ethanolamine and LiCl were supplemented to the low density cell suspension cultures and microdroplet cell cultures to screen for their cell division and somatic embryogenesis activity. Incubation of callus or the inoculum employed for low density cell suspension cultures and microdroplet cell cultures with polyethylene glycol was found critical for induction of somatic embryogenesis. Somatic embryogenesis at a frequency of 1.19, 3.16 and 6.51 per 106 cells was achieved in the callus, low density cell suspension cultures and microdroplet cell cultures, respectively. Advantages of employing microdroplet cell cultures for high frequency production of somatic embryos and its application in genetic transformation protocols are discussed

Epidemiology and zoonotic potential of Livestock-associated Staphylococcus aureus isolated at Tamil Nadu, India

Abstract Background Staphylococcus aureus is part of normal flora and also an opportunistic pathogen responsible for a wide range of infections in both humans and animals. Livestock-associated S. aureus (LA-SA) has gained importance in recent years due to its increased prevalence in recent years, becoming a worry in public health view. This study aimed to study the epidemiology of LA-SA strains in Madurai district, Tamil Nadu, India. Methods A total of 255 samples were collected from bovine and other small ruminants like goats and sheep nares (n = 129 and n = 126 respectively). Nasal swab samples were collected from study animals with sterile sample collecting cotton swabs (Hi-Media, Mumbai). Samples were transported to the lab in Cary-Blair Transport media for further analysis. The samples were tested for S. aureus using antibiotic selection and PCR-based assays. The pathogenicity of the bacteria was assessed using chicken embryo models and liver cross-sections were used for histopathology studies. Results The prevalence rate in bovine-associated samples was 42.63% but relatively low in the case of small ruminants associated samples with 28.57% only. The overall prevalence of S. aureus is found to 35.6% and MRSA 10.98% among the study samples. The antibiogram results that LA-SA isolates were susceptible to aminoglycosides and tetracyclines but resistant to β-lactam drugs. The biofilm formation results showed that the LA-SA isolates are weak to high-capacity biofilm formers. The enterotoxigenic patterns revealed that most of the isolated strains are enterotoxigenic and possess classical enterotoxins. The survival analysis of chicken embryos suggested that the Bovine-associated strains were moderately pathogenic. Conclusion The study concluded that economically important livestock animals can act as reservoirs for multi-drug resistant and pathogenic which in-turn is a concern for public health as well as livestock health

Recent advances in green synthesized nanoparticles for bactericidal and wound healing applications

Nanotechnology has become an exciting area of research in diverse fields, such as: healthcare, food, agriculture, cosmetics, paints, lubricants, fuel additives and other fields. This review is a novel effort to update the practioneers about the most current developments in the widespread use of green synthesized nanoparticles in medicine. Biosynthesis is widely preferred among different modes of nanoparticle synthesis since they do not require toxic chemical usage and they are environment-friendly. In the green bioprocess, plant, algal, fungal and cyanobacterial extract solutions have been utilized as nucleation/capping agents to develop effective nanomaterials for advanced medical applications. Several metal salts, such as silver, zinc, titanium and other inorganic salts, were utilized to fabricate innovative nanoparticles for healthcare applications. Irrespective of the type of wound, infection in the wound area is a widespread problem. Micro-organisms, the prime reason for wound complications, are gradually gaining resistance against the commonly used antimicrobial drugs. This necessitates the need to generate nanoparticles with efficient antimicrobial potential to keep the pathogenic microbes under control. These nanoparticles can be topically applied as an ointment and also be used by incorporating them into hydrogels, sponges or electrospun nanofibers. The main aim of this review is to highlight the recent advances in the Ag, ZnO and TiO2 nanoparticles with possible wound healing applications, coupled with the bactericidal ability of a green synthesis process