Synthesis of silver nanoparticles from in vitro derived plants and callus cultures of Costus speciosus (Koen.); Assessment of antibacterial activity

This study demonstrates for the first time the efficiencies of in vitro derived plantsand callus cultures of Costus speciosus extract in the rapid biosynthesis of stable silve rnanoparticles. Synthesis of silver nanoparticles may be influenced directly or indirectly byphytochemicals in plants such as phenolics, flavonoids, and diosgenin compounds. Thisstudy also highlights a cost effective and environment friendly technique for green synthesisof silver nanoparticles. These silver nanoparticles were found to be highly toxic againstdifferent multi drug resistant clinical samples such as gram-positive bacteria Bacillus subtilis and Staphylococcus aureus, and the gram-negative bacteria Escherichia coli and Klebsiella pneumoniae. This also provides evidence for developing large scale commercial productionof value-added products for biomedical / nanotechnology based industries, which is animportant step in the field of application of nanotechnology

Role of salicyclic acid on conifer somatic embryogenesis

This review paper highlights about the role of salicyclic acid on somatic embryogenesis and also recent updates on cloning mature trees of  conifers using salicyclic acid were discussed. Salicyclic acid (SA) is a mobile molecule, which is capable of acting as a cell signal that senses, amplifies, and transmit information from a cell and might help in programming  towards embryogenesis during cloning. Very recently incorporation of 1.0 mg-1 SA in the DCR induction medium was found to be optimum for all  the genotypes of P. roxburghii in terms of increasing the percentage of somatic embryogenesis compared against control. Therefore, salicyclic acid can be used as growth regulator in conifer somatic embryogenesis and its use might help to solve the low initiation frequencies of many other recalcitrant pines. However, the mechanism of salicylate-induced  differentiation in plants is not known, although salicylate is a signal molecule implicated in eliciting many physiological functions in plants

Factors influencing cloning mature trees of conifers

At present an embryogenic system derived from vegetative shoot apices or secondaryneedles of mature pines have been well established in at least a few conifers. This is themajor breakthrough in forest biotechnology, and certainly solves the current problems oftree breeding. During cloning of mature conifers, isolated somatic cells under any externalstress conditions of cold/heat or chemical are induced to form a somatic embryo. Cloning ofmature conifers was influenced by many factors such as pH, carbohydrate source, plantgrowth regulators, and activated charcoal. The embryogenic cells are very important becausethey differentiate, and undergo cleavage polyembryony to form somatic embryos at a latertime in conifers

Activation of cambial layer influences cloning of mature trees of conifers

The shoot apical meristems are organized pools of undifferentiated or embryonic cells (stem cells) maintained by a dynamic balance between cell division and differentiation. On the basis of our mature tree cloning of pines, it is found that actively dividing and totipotent cells (stem cells) are positioned only at the cambial layer of the apical meristematic tissue in conifers, so that their growth and division under in vitro conditions leading to a continuous flow of progeny cells. These progeny cells (stem cells) under stress conditions (cold/heat) undergo differentiation due to signal activation in cambial region and leading to the embryogenic pathway in conifers. On the other hand the rest of the layers (epidermis, cortex region and central pith or medulla) of the transverse thin section of shoot apical meristems of mature trees have  induced non--embryogenic tissue under in vitro conditions in conifers

Influence of bud break and apical meristematic tissue competence during cloning mature trees of conifers

This review paper highlights the influence of bud break and apical meristematic tissue competence in inducing embryogenic tissue during cloning mature trees of conifers. Bud burst depends on dormancy release by chilling or heat due to increase in the day temperature, and accumulation of thermal time above a species-specific threshold. The buds collected immediately after the bud burst were found very responsive for the in vitro cloningof P. kesiya, P. roxburghii and P. wallichiana, P. patula, and P. sylvestris, This might be duethe activation of the apical meristematic cells showing active growth of shoots in most of theconifers. The active dividing and totipotent cells might be positioned only at the cambiallayer of the apical meristematic tissue in conifers, so that their growth and division leads to acontinuous flow of progeny cells. These cambial layer cells under stress conditions undergodifferentiation and leading to the embryogenic pathway in conifers

Smoke promoted in vitro seed germination of Pholidota pallida Lindl.

This study reports the influence of smoke saturated water (SSW) on asymbiotic seed germination and an early differentiation of protocorms and plant regeneration of Pholidota pallida Lindl. High percentage germination (85%), and percentage of plant let recovery (71%)was achieved by culturing seeds on Mitra et al. (1976) basal medium supplemented with 10%(v/v) SSW. Well-rooted shoots were transferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1) and 90% survived. Therefore, smoke saturated water is an efficient, cheap and easy way to improve the seed germination, in vitro development and exvitro establishment of orchids

Recent advances in plant derived vaccine antigens against human infectious diseases

The use of plants for the production of vaccine is one of the important applications in the modern medicine. There are many advantages of using plants as the production system compared to traditional mammalian system. Many plant species have been exploited to accumulate vaccine antigens for human infectious diseases, and vaccine candidates are approaching the market. The transgenic plants are considered as cheap source and found alternative approach to fermentation for large-scale production of vaccine antigens. The autotrophic growth of plants requires only soil minerals, water, nitrogen, sunlight energy for the synthesis of vaccine antigens. Therefore, vaccine production by using plants is one of the cheap and efficient technologies. This review covers the recent advances of plant derived vaccine antigens for the prevention of human infectious diseases and focuses on the current methods

Smoke saturated water promoted in vitro seed germination of an epiphytic orchid Oberonia ensiformis (Rees) Lindl.

This study highlights for the first time an in vitro seed germination of an epiphytic orchid Oberonia ensiformis (Rees) Lindl, from the Western Ghat Forest of Karnataka state,India promoted by smoke saturated water (SSW). High percentage germination (85%) andhigh percentage of plantlet recovery (73%) was achieved by culturing seeds on Mitra et al.(1976) basal medium supplemented with 10% (v/v) SSW. Well-rooted shoots weretransferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1) and 90%survived. Therefore, the role of SSW as a natural growth regulator at different stages ofdevelopment from seed germination to plant regeneration has been confirmed

Antibacterial activity of silver nanoparticles synthesized by using whole plant extracts of Clitoria ternatea

This study highlights the synthesis of silver nanoparticles using whole plant extracts of Clitoria ternatea. Antibacterial activity of silver nanoparticles was assessed by using disc diffusion method against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae, since Bacillus species and S. aureus strains may cause diarrhoea and an enteropathogenic form of E. coli, and Klebsiella species may cause food poising. The results of this study clearly indicate that silver nanoparticles synthesized from plant extracts of Clitoria ternatea has many pharmaceutical applications for the control of deadly pathogens

Silver nanoparticles synthesized by in vitro derived plants and callus cultures of Clitoria ternatea; Evaluation of antimicrobial activity

This paper highlights for the first time the preparation and synthesis of silver nanoparticles from the callus and in vitro derived plant roots of white flowered variety of Clitora ternatea. The efficiency of antimicrobial activity of silver nanoparticles towards the clinical samples was assessed. Our study confirmed that these silver nanoparticles were found to be highly toxic and provides once again the pharmaceutical evidence of the medicinal plant Clitoria ternatea. Therefore, the use of silver nanoparticles should emerge as one of the novel approaches in many disease therapies, and applications of plant extract silver nanoparticles should be exploited for the medical treatment