Rapid in vitro propagation of Saussurea lappa, an endangered medicinal plant, through multiple shoot cultures

Summary Rapid micropropagation of Saussurea lappa C. B. Clarke, an endangered medicinal plant endemic in the valley of Kashmir and western Himalayas of northern India, was achieved by culturing shoot tips (0.5–1 cm) of 2-wk-old seedlings on Murashige and Skoog’s medium (MS) supplemented with thidiazuron (TDZ, 0.45 μM). Although callus-free multiple shoots were obtained both on N⁶-benzyladenine- (BA) and TDZ-containing media, TDZ was most effective (90%) in inducing multiple shoots. Shoot tips containing proliferative buds were divided into equal halves and subcultured on MS liquid medium containing 0.225 μM TDZ for further multiplication and elongation. Multiplication of induced shoot buds was more effective when cultured in liquid medium than on agar-solidified medium. Shoots (8–10 cm) developed were rooted in MS medium containing naphthaleneacetic acid (NAA, 1.07 μM). Micropropagated plantlets were successfully transferred to soil after hardening.     

An Efficient Rice Transformation System Utilizing Mature Seed-derived Explants and a Portable,Inexpensive Particle Bombardment Device

We developed a practical and efficient gene transfer system for indica rice utilizing mature-seed derived explants and a simple bombardment device which uses compressed helium for accelerating DNA-coated metal particles. Unlike instruments which have been described in the literature previously, this new bombardment device, which is an improvement of the particle inflow concept, does not require vacuum. This attribute simplifies the transformation procedure significantly and it makes rice transformation technology accessible to laboratories which may not have the resources to invest in more expensive particle bombardment instruments. We determined experimentally that we could recover transgenic rice plants utilizing three different particle bombardment instruments at comparable frequencies.     

Occurrence of Marbled Shrimp <Emphasis Type="Italic">Saron marmoratus</Emphasis> (Olivier, 1811) (Decapoda: Caridea: Hippolytidae) in Lakshadweep Archipelago,India

Two juvenile specimens of Saron marmoratus (Olivier, 1811) were collected from the inter tidal lagoon area of Eastern side of Agatti Island, Lakshadweep on November 4, 2013. These shrimp are brown and slightly green in color with yellow and white speckled spot and having a typical tuft of cirri on the back. Marbled shrimps are highly demanded and good priced in the marine aquarium trade. This is a new record to the Lakshadweep waters.     

Effect of manganese ions on benzyladenine-induced growth and chlorophyll synthesis in excised cucumber cotyledons

The behaviour of endogenous Mn²⁺ was studied by electron spin resonance spectro-scopy during benzyladenine-induced growth of excised cucumber ( Cucumis sativis L. cv. Long green) cotyledons. The level of endogenous Mn²⁺ was decreased by ben-zyladenine treatment, most pronounced after 96 h. MnCl₂ applied alone promoted chlorophyll synthesis at relatively low concentrations but in the presence of ben-zyladenine higher concentrations of MnCl₂ were required for stimulation of chlorophyll synthesis. A pronounced increase in growth was observed when Mn²⁺ was applied with benzyladenine at 96 h, when the decline in the endogenous level of paramagnetic Mn²⁺ was maximal.     

Preparation and 17O NMR Spectra of 17O-Labeled Thymidine 5′-Phosphate Triesters,Alkylphosphonates, Dialkylphosphinates,and Phosphoramidates

Abstract

The ¹⁷O chemical shifts of the title compounds cover a range of values and appear to be useful for the assignment of structure. However, the individual diastereomers of derivatives containing a stereogenic phosphorus center did not display discernably different ¹⁷O chemical shifts.     

Identification and Validation of Reference Genes and Their Impact on Normalized Gene Expression Studies across Cultivated and Wild Cicer Species

Quantitative Real-Time PCR (qPCR) is a preferred and reliable method for accurate quantification of gene expression to understand precise gene functions. A total of 25 candidate reference genes including traditional and new generation reference genes were selected and evaluated in a diverse set of chickpea samples. The samples used in this study included nine chickpea genotypes (Cicer spp.) comprising of cultivated and wild species, six abiotic stress treatments (drought, salinity, high vapor pressure deficit, abscisic acid, cold and heat shock), and five diverse tissues (leaf, root, flower, seedlings and seed). The geNorm, NormFinder and RefFinder algorithms used to identify stably expressed genes in four sample sets revealed stable expression of UCP and G6PD genes across genotypes, while TIP41 and CAC were highly stable under abiotic stress conditions. While PP2A and ABCT genes were ranked as best for different tissues, ABCT, UCP and CAC were most stable across all samples. This study demonstrated the usefulness of new generation reference genes for more accurate qPCR based gene expression quantification in cultivated as well as wild chickpea species. Validation of the best reference genes was carried out by studying their impact on normalization of aquaporin genes PIP1;4 and TIP3;1, in three contrasting chickpea genotypes under high vapor pressure deficit (VPD) treatment. The chickpea TIP3;1 gene got significantly up regulated under high VPD conditions with higher relative expression in the drought susceptible genotype, confirming the suitability of the selected reference genes for expression analysis. This is the first comprehensive study on the stability of the new generation reference genes for qPCR studies in chickpea across species, different tissues and abiotic stresses.     

Aldose reductase expression contributes in sorbitol accumulation and 4-hydroxynon-2-enal detoxification in two foxtail millet (<Emphasis Type="Italic">Setaria italic</Emphasis>a L.) cultivars with different salt stress tolerance

Salt stress is a major environmental factor in arid and semi-arid regions and influences many aspects of plant development. Salinity results in generation of various free radicals that can potentially damage the cellular constituents in plants. Plants were able to effectively reduce the damage caused by these free radicals by a way of enzymatic and non enzymatic defenses for better survival. Enhanced efficacy of antioxidative enzyme systems such as superoxide dismutase, catalase and ascarbate peroxidase was well documented in several plants subjected to salinity stress. Aldose reductase, an important enzyme is also known to detoxify free toxic aldehydes like HNE (4-hydroxynon-2-enal, a hydroxyalkenal) generated during oxidative damage of cellular components. However, the role of aldose reductase to impart tolerance to the plants under salt stress has not been studied in any detail. Therefore, we were interested to study the aldose reductase activity and its expression to gain an insight into the role of aldose reductase in imparting tolerance to foxtail millet cultivars (viz., Cv. Prasad and Lepakshi) subjected to NaCl stress. We observed that subjecting foxtail millets to increasing levels of stress significantly increased aldose reductase activity and in a way that correlated positively with elevated levels of sorbitol, an osmotic solute involved in osmotic balance. This suggests the involvement of aldose reductase in sorbitol biosynthesis in foxtail millet. Additionally, we observed higher levels of 4-hydroxynon-2-enal, a major lipid peroxidation product, in the susceptible than the tolerant cultivar indicating a higher proportion of cellular damage in former than in the latter. This high content of 4-hydroxynon-2-enal in the susceptible cultivar was negatively correlated with its aldose reductase activity, indicating the involvement of aldose reductase in detoxification of 4-hydroxynon-2-enal. 4-hydroxynon-2-enal is also known to be a catalyzed by glutathione-S-transferase. Glutathione-S-transferase activity was found higher in the tolerant foxtail millet than the sensitive cultivar: the tolerant cultivar showed a low 4-hydroxynon-2-enal content compared to the susceptible cultivar, demonstrating a possible mechanism for detoxification of 4-hydroxynon-2-enal by two enzymes, glutathione-S-transferase and aldose reductase in plants under stressful conditions.     

High-Resolution Functional Profiling of a Gammaherpesvirus RTA Locus in the Context of the Viral Genome

Gammaherpesviruses Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus are associated with multiple human cancers. Our goal was to develop a quantitative, high-throughput functional profiling system to identify viral cis-elements and protein subdomains critical for virus replication in the context of the herpesvirus genome. In gamma-2 herpesviruses, the transactivating factor RTA is essential for initiation of lytic gene expression and viral reactivation. We used the RTA locus as a model to develop the functional profiling approach. The mutant murine gammaherpesvirus 68 viral library, containing 15-bp random insertions in the RTA locus, was passaged in murine fibroblast cells for multiple rounds of selection. The effect of each 15-bp insertion was characterized using fluorescent-PCR profiling. We identified 1,229 insertions in the 3,845-bp RTA locus, of which 393, 282, and 554 were critically impaired, attenuated, and tolerated, respectively, for viral growth. The functional profiling phenotypes were verified by examining several individual RTA mutant clones for transactivating function of the RTA promoter and transcomplementing function of the RTA-null virus. Thus, the profiling approach enabled us to identify several novel functional domains in the RTA locus in the context of the herpesvirus genome. Importantly, our study has demonstrated a novel system to conduct high-density functional genetic mapping. The genome-scale expansion of the genetic profiling approach will expedite the functional genomics research on herpesvirus.