In vitro propagation of Gentiana kurroo — an indigenous threatened plant of medicinal importance

Shoot multiplication of Gentiana kurroo Royle, a threatened medicinal plant species, was achieved in vitro using shoot tips and nodal segments as explants. Fifteen-fold shoot multiplication occurred every 6 weeks on Murashige and Skoog's medium (MS) containing 8.9 M benzyladenine and 1.1 M 1-naphthaleneacetic acid. Rooting was accomplished successfully in excised shoots grown on MS basal medium containing 6% sucrose.Abbreviations BA 6-benzyladenine - IAA Indole-3-acetic acid - IBA Indole-3-butyric acid - MS Murashige and Skoog's medium - NAA 1-naphthaleneacetic acid     

In vitro culture of glochidia of the threatened freshwater mussel Unio crassus Philipsson 1788 – the dilution problem

We applied in vitro techniques in culturing glochidia of the thick-shelled river mussel Unio crassus, seriously threatened European species. Glochidia were freshly isolated from a gravid female. The sterile phase of the cultures was terminated at different time points to assess the optimal length of this phase. We imitated the process of juvenile excision from a fish host by diluting the culture with water at regular time intervals. The metamorphosed juveniles that survived until the end of the experiment and started growing their shells were observed for 24–27 days from the start of the culture in samples diluted for the first time between days 13 and 17. Long-lasting cultures usually became infected and died, whereas in those that were terminated too early, glochidia were unable to develop further in clean water. The transfer of juveniles from an artificial medium to pure water should be done gradually, through a series of dilutions, so that the larvae have the opportunity to feed on the diluted medium after metamorphosis. Only individuals with an active foot capable of operating outside the shell were ready to inhabit water and forage on solid food from the external environment.     

In vitro propagation and conservation of Satureja avromanica Maroofi—an indigenous threatened medicinal plant of Iran

Physiology and Molecular Biology of Plants - An efficient and rapid in vitro propagation system for Satureja avromanica, a rare and endangered folk medicinal plant of Iran was developed through the...     

Rapid in vitro differentiation of Sesbania bispinosa plants — a leguminous shrub

Multiple shoots differentiated from hypocotyl explants of Sesbania bispinosa (Jacq.) W.F. Wight, a leguminous woody shrub, when cultured on Gamborg's basal medium alone or in combination with 6-benzyl aminopurine (10^–7–10^–4 M). For cotyledonary explants 6-benzyl aminopurine (10^–6–10^–4 M) was necessary. The shoots rooted when cultured on Gamborg's basal medium containing indole-3-butyric acid (10^-5 M). Plantlets thus formed were transferred to soil where they have flowered and also set fruits.     

NanoAOX—a novel nanoparticle and antioxidant mixture enhances the growth of plants in vitro and in vivo

In Vitro Cellular & Developmental Biology - Plant - The global food crisis is an issue affecting 1 billion people worldwide—it is critical that a solution be developed to provide the...     

Conservation strategies for threatened medicinal plant – Barleria prionitis L. – using in vitro and ex vitro propagation techniques

Over-utilisation and continuous depletion of medicinal plants have affected their supply and loss of genetic diversity. Hence the current study is based on conservation strategies for threatened medicinal plants with special reference to Barleria prionitis L. using in vitro and ex vitro propagation techniques. We have developed here a protocol for plant regeneration of Barleria prionitis L. We have also developed an efficient system of vegetative propagation of Barleria prionitis L. through stem cuttings using revive rooting hormones. These studies can be useful for conservation strategies of this important medicinal plant.     

How past and present influence the foraging of clonal plants?

Clonal plants spreading horizontally and forming a network structure of ramets exhibit complex growth patterns to maximize resource uptake from the environment. They respond to spatial heterogeneity by changing their internode length or branching frequency. Ramets definitively root in the soil but stay interconnected for a varying period of time thus allowing an exchange of spatial and temporal information. We quantified the foraging response of clonal plants depending on the local soil quality sampled by the rooting ramet (i.e. the present information) and the resource variability sampled by the older ramets (i.e. the past information). We demonstrated that two related species, Potentilla reptans and P. anserina, responded similarly to the local quality of their environment by decreasing their internode length in response to nutrient-rich soil. Only P. reptans responded to resource variability by decreasing its internode length. In both species, the experience acquired by older ramets influenced the plastic response of new rooted ramets: the internode length between ramets depended not only on the soil quality locally sampled but also on the soil quality previously sampled by older ramets. We quantified the effect of the information perceived at different time and space on the foraging behavior of clonal plants by showing a non-linear response of the ramet rooting in the soil of a given quality. These data suggest that the decision to grow a stolon or to root a ramet at a given distance from the older ramet results from the integration of the past and present information about the richness and the variability of the environment.     

Temperate—Zone plants in the tropics

The success or failure of temperate-zone plants transferred to the tropics—blackberry, Boysenberry, corn, grape, plum, raspberry, tomato, Youngberry and others have been tried—is controlled not only by disease, humidity and temperature, but also (in many cases) by the shorter day-length and absence of cold-dormancy there.     

In vitro and in vivo antifungal activates of the essential oils of various plants against strawberry grey mould disease agent Botrytis cinerea

In order to investigate the effects of antifungal essential oils on postharvest decay and some quality factors of strawberry fruit, experiments were conducted under in vitro and in vivo conditions. The antifungal activates of essential oils obtained from fennel, anis, peppermint and cinnamon at concentrations 0, 200, 400, 600 and 800 μL L^?1 were investigated against Botrytis cinerea with four replications. In vitro results showed that the growth of B. cinerea was completely inhibited by fennel, cinnamon and anis essential oils at relatively low concentrations (400–800 μL L^?1). In vivo results showed that all the used essential oils at all applied concentrations caused an increase in the shelf life and inhibited of B. cinerea growth on strawberry fruits completely in comparison to the controls. The results of this study confirmed the antifungal effect of four essential oils in both in vitro and on fruit postharvest.     

In vitro metabolic engineering for the production of α-ketoglutarate

α-Ketoglutarate (aKG) represents a central intermediate of cell metabolism. It is used for medical treatments and as a chemical building block. Enzymatic cascade reactions have the potential to sustainably synthesize this natural product. Here we report a systems biocatalysis approach for an in vitro reaction set-up to produce aKG from glucuronate using the oxidative pathway of uronic acids. Because of two dehydrations, a decarboxylation, and reaction conditions favoring oxidation, the pathway is driven thermodynamically towards complete product formation. The five enzymes (including one for cofactor recycling) were first investigated individually to define optimal reaction conditions for the cascade reaction. Then, the kinetic parameters were determined under these conditions and the inhibitory effects of substrate, intermediates, and product were evaluated. As cofactor supply is critical for the cascade reaction, various set-ups were tested: increasing concentrations of the recycling enzyme, different initial NAD⁺ concentrations, as well as the use of a bubble reactor for faster oxygen diffusion. Finally, we were able to convert 10 g L⁻¹ glucuronate with 92% yield of aKG within 5 h. The maximum productivity of 2.8 g L⁻¹ h⁻¹ is the second highest reported in the biotechnological synthesis of aKG.     

In vitro Formation of Triple-Stranded DNA Structures in the Human α1-Antitrypsin Gene

We analyzed the possibility of triplex formation in the human 1-antitrypsin gene. Conditions and nucleotide sequence dependence of triplex formation and thermostability of the product were determined.     

Biomechanical highlights — the personal miscellany of a decade

Developments of the past decade, primarily in biomechanics, are characterized through personal recollections. Topics covered include pressure treatment of hypertrophic scars, laser eradication of tattoos, amputation stump and artificial limb interactions, elbow arthoplasty, disability rehabilitation and training for sports performance, functional electrical stimulation and joint goniometry. The review is prefaced by comments on the present day context and resource environment of bioengineering research and ends by discussing the anticipated advent of health maintenance orientated community care as the activity of first priority for the future.     

Conservation of a phenomenon: rapid,reversible colour change in both sexes of one of the world’s most threatened damselflies

Physiological colour change is rare in insects. Unusually, both the males and females of Spesbona angusta (Odonata: Platycnemididae), Red Listed as Endangered, are capable of rapid and reversible colour change. There is only one known population of this species, which occurs in a unique habitat in the Cape Floristic Region, South Africa. Appreciation of this unusual phenomenon of distinct physiological colour change helps us appreciate that we need to conserve phenomena in the insect world as well as the species themselves. Using controlled experiments, we evaluated the importance of ambient temperature as the possible primary cue for physiological colour change. We found that S. angusta responds rapidly to short-term changes in ambient temperature, even in the absence of additional environmental stimuli and without the body temperature matching the ambient temperature. Colour change is reversible when temperature returns to its earlier level. The reason why S. angusta shows this rapid and reversible colour change may be a combination of reproductive enhancement, competitive advantage and thermoregulation. This colour change appears to have strong selective advantage in a very particular habitat type, meaning that careful conservation of its habitat in all respects is important, and must be considered in any possible future translocations.     

In vitro regeneration of plantlets in Fagraea fragrans Roxb. — a tropical tree

Different vegetative parts of Fagraea fragrans Roxb., a valuable timber tree of South East Asia, were used as explants in in vitro studies.Nodal segments showed the best growth response as numerous adventitious shoots were regenerated in MS medium supplemented with Benzyl adenine (BA, 8.8 um) and 2,4-dichlorophenoxyacetic acid (2,4-D, 0.5 um). Shoot buds also developed from the leaf and root segments that were subcultured. The detailed process of callus growth and differentiation leading to the formation of whole plantlets is described. Uniform plantlets obtained could be transplanted successfully in soil.     

Could coastal plants in western Amazonia be relicts of past marine incursions?

The rainforests of Amazonia comprise some of the most biologically diverse ecosystems on Earth. Despite this high biodiversity, little is known about how landscape changes that took place in deep history have affected the assembly of its species, and whether the impact of such changes on biodiversity can still be observed. Here, we present a hypothesis to explain our observation that plants typical of Neotropical coastal habitats also occur in western Amazonia, in some cases thousands of kilometres away from the coast. Evidence on their current distribution, dispersal biology and divergence times estimated from molecular phylogenies suggest that these plants may be the legacy of the large marine‐influenced embayment that dominated the area for millions of years in the Neogene. We hypothesize that coastal plants dispersed along the shores of this embayment and persisted as inland relicts after the marine incursion(s) retreated, probably with the aid of changes in soil conditions caused by the deposition of marine sediments. This dispersal corridor may also have facilitated the colonization of coastal environments by Amazonian lineages. These scenarios could imply an unexpected coastal source that has contributed to Amazonia's high floristic diversity and led to disjunct distributions across the Neotropics. We highlight the need for future studies and additional evidence to validate and shed further light on this potentially important pattern.     

In vitro and in silico analysis of the Aspergillus nidulans DNA–CreA repressor interactions

The CreA protein mediates carbon catabolite repression in the fungus Aspergillus nidulans. Its DNA-binding domain belongs to the Cys₂-His₂ class, binding specifically to a 5′ SYGGRG 3′ nucleotide sequence. EMSA experiments showed that the CreA(G27D) mutation resulted in a 30-fold increase of the K_diss, and footprinting revealed a altered pattern of protein/DNA contacts. We modeled the CreA and the CreA(G27D) complexes in silico. A 15?ns molecular dynamics simulation of the solvated CreA(G27D) and CreA models was carried out using the MOE 2007.09 suite and the Amber99 force field. We have focused our analysis in residues Arg14, Glu16, His17, and Arg20 and Arg44, Asp46, and Arg50, previously, shown to be responsible for the specific contacts of the two Zn fingers. The electrostatic and the total potential energies showed the CreA(G27D) mutation to decrease the affinity of the complex, in agreement with the K_diss′s values. The in silico approach highlighted the role of the inter-finger linker. We identified several differential structural characteristics of the CreA and CreA(G27D)/DNA complexes and observed that the latter resulted in a lower dynamic flexibility of the complex.     

In vitro and in vivo analyses of the role of the carboxysomal β-type carbonic anhydrase of the cyanobacterium Synechococcus elongatus in carboxylation of ribulose-1,5-bisphosphate

The carboxylase activities of crude carboxysome preparations obtained from the wild-type Synechococcus elongatus strain PCC 7942 strain and the mutant defective in the carboxysomal carbonic anhydrase (CA) were compared. The carboxylation reaction required high concentrations of bicarbonate and was not even saturated at 50 mM bicarbonate. With the initial concentrations of 50 mM and 25 mM for bicarbonate and ribulose-1,5-bisphosphate (RuBP), respectively, the initial rate of RuBP carboxylation by the mutant carboxysome (0.22 μmol mg^?1 protein min^?1) was only 30 % of that observed for the wild-type carboxysomes (0.71 μmol mg^?1 protein min^?1), indicating the importance of the presence of CA in efficient catalysis by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). While the mutant defective in the ccmLMNO genes, which lacks the carboxysome structure, could grow under aeration with 2 % (v/v) CO₂ in air, the mutant defective in ccaA as well as ccmLMNO required 5 % (v/v) CO₂ for growth, indicating that the cytoplasmically localized CcaA helped utilization of CO₂ by the cytoplasmically localized Rubisco by counteracting the action of the CO₂ hydration mechanism. The results predict that overexpression of Rubisco would hardly enhance CO₂ fixation by the cyanobacterium at CO₂ levels lower than 5 %, unless Rubisco is properly organized into carboxysomes.