Developing Transgenic Jatropha Using the SbNHX1 Gene from an Extreme Halophyte for Cultivation in Saline Wasteland

Jatropha is an important second-generation biofuel plant. Salinity is a major factor adversely impacting the growth and yield of several plants including Jatropha. SbNHX1 is a vacuolar Na⁺/H⁺ antiporter gene that compartmentalises excess Na⁺ ions into the vacuole and maintains ion homeostasis. We have previously cloned and characterised the SbNHX1 gene from an extreme halophyte, Salicornia brachiata. Transgenic plants of Jatropha curcas with the SbNHX1 gene were developed using microprojectile bombardment mediated transformation. Integration of the transgene was confirmed by PCR and Rt-PCR and the copy number was determined by real time qPCR. The present study of engineering salt tolerance in Jatropha is the first report to date. Salt tolerance of the transgenic lines JL2, JL8 and JL19 was confirmed by leaf senescence assay, chlorophyll estimation, plant growth, ion content, electrolyte leakage and malondialdehyde (MDA) content analysis. Transgenic lines showed better salt tolerance than WT up to 200 mM NaCl. Imparting salt tolerance to Jatropha using the SbNHX1 gene may open up the possibility of cultivating it in marginal salty land, releasing arable land presently under Jatropha cultivation for agriculture purposes. Apart from this, transgenic Jatropha can be cultivated with brackish water, opening up the possibility of sustainable cultivation of this biofuel plant in salty coastal areas.     

Value-added food: single cell protein

The alarming rate of population growth has increased the demand for food production in third-world countries leading to a yawning gap in demand and supply. This has led to an increase in the number of hungry and chronically malnourished people. This situation has created a demand for the formulation of innovative and alternative proteinaceous food sources. Single cell protein (SCP) production is a major step in this direction. SCP is the protein extracted from cultivated microbial biomass. It can be used for protein supplementation of a staple diet by replacing costly conventional sources like soymeal and fishmeal to alleviate the problem of protein scarcity. Moreover, bioconversion of agricultural and industrial wastes to protein-rich food and fodder stocks has an additional benefit of making the final product cheaper. This would also offset the negative cost value of wastes used as substrate to yield SCP. Further, it would make food production less dependent upon land and relieve the pressure on agriculture. This article reviews diversified aspects of SCP as an alternative protein-supplementing source. Various potential strains and substrates that could be utilized for SCP production are described. Nutritive value and removal of nucleic acids and toxins from SCP as a protein-supplementing source are discussed. New processes need to be exploited to improve yield. In that direction the solid state fermentation (SSF) method and its advantages for SCP production are highlighted.     

Modern pollen rain from the Biligirirangan-Melagiri hills of southern Eastern Ghats, India

A total of 39 soil surface samples collected between 11 degrees 30'N 76 degrees 45'E and 12 degrees 45'N 78 degrees 15'E from the mainly deciduous forests in the Biligirirangan-Melagiri hills of the southern Eastern Ghats were analysed for their pollen content. The samples are distributed among four different deciduous and evergreen vegetation types between 210 and 1700m altitudes and fall within three distinct rainfall regimes. The aims of this paper are to provide new data on the modern pollen rain from the Southern Eastern Ghats, a region characterized by a unique and complex climate and vegetation, and to interpret these data using multivariate statistics and the diagram of pollen percentages. We could distinguish first between the deciduous and the evergreen forests and then also between different types of deciduous forest. The distinction between the evergreen and deciduous forests was based on a humidity gradient and that among the deciduous forests on a physiognomic gradient identified through correspondence analysis. The above analysis also allowed us to identify a set of 14 pollen taxa markers and 11 associated pollen taxa that help differentiate the evergreen from deciduous forests. Similarly, a set of 12 pollen taxa markers and six associated pollen taxa was demarcated to help distinguish woodland formations from scrub and thicket formations, among the deciduous vegetation. We could also differentiate amongst the four distinct vegetation types sampled, on the basis of distinct associations of both tree and herb pollen taxa according to their relative abundance in the pollen diagram as well as on the proportion of total arboreal pollen. The ground cover of grasses and other herbaceous plants in the deciduous forests is effectively demonstrated by percentages of non-arboreal pollen varying between 40 and 70%. The 1000m altitude limit reflecting a gradient of humidity and the physiognomic gradient among deciduous forests seem to be important in this region.     

Using food for different purposes: female responses to prey in the predator Coccinella septempunctata L. (Coleoptera: Coccinellidae)

Abstract.  1. Although predatory insects often feed on diverse prey, their reproductive activity may be linked most strongly to a more restricted range of prey. The propensity of adult females of the ladybird beetle, Coccinella septempunctata L., to attack two natural prey species, pea aphids [ Acyrthosiphon pisum (Harris)] and alfalfa weevil larvae [ Hypera postica (Gyllenhal)], was compared, and the degree to which ladybird egg production depends on consumption of aphids vs. weevils was assessed.
2. Coccinella septempunctata females more readily attacked aphids than weevil larvae. This was true regardless of whether females had fed previously on aphids or on weevil larvae.
3. When females were provided with few to many aphids daily, or few aphids plus an excess number of weevil larvae, their rates of egg production depended primarily on the number of aphids consumed.
4. Addition of weevil larvae to diets of limited numbers of aphids increased egg production, but only modestly. Thus, consumption of weevil larvae may have served mostly for self-maintenance, thereby enabling females to use for egg production more of the nutrients and energy obtained from limited consumption of aphids.
5. The females' linkage of egg production primarily to aphid rather than weevil consumption may be adaptive, as their offspring are much less able as larvae to survive and mature on a diet of weevils rather than aphids.     

Depletion of B cells in murine lupus: efficacy and resistance

In mice, genetic deletion of B cells strongly suppresses systemic autoimmunity, providing a rationale for depleting B cells to treat autoimmunity. In fact, B cell depletion with rituximab is approved for rheumatoid arthritis patients, and clinical trials are underway for systemic lupus erythematosus. Yet, basic questions concerning mechanism, pathologic effect, and extent of B cell depletion cannot be easily studied in humans. To better understand how B cell depletion affects autoimmunity, we have generated a transgenic mouse expressing human CD20 on B cells in an autoimmune-prone MRL/MpJ-Fas(lpr) (MRL/lpr) background. Using high doses of a murine anti-human CD20 mAb, we were able to achieve significant depletion of B cells, which in turn markedly ameliorated clinical and histologic disease as well as antinuclear Ab and serum autoantibody levels. However, we also found that B cells were quite refractory to depletion in autoimmune-prone strains compared with non-autoimmune-prone strains. This was true with multiple anti-CD20 Abs, including a new anti-mouse CD20 Ab, and in several different autoimmune-prone strains. Thus, whereas successful B cell depletion is a promising therapy for lupus, at least some patients might be resistant to the therapy as a byproduct of the autoimmune condition itself.     

Regulatory rewiring confers serotype‐specific hyper‐virulence in the human pathogen group A Streptococcus

Phenotypic heterogeneity is commonly observed between isolates of a given pathogen. Epidemiological analyses have identified that some serotypes of the group A Streptococcus (GAS) are non‐randomly associated with particular disease manifestations. Here, we present evidence that a contributing factor to the association of serotype M3 GAS isolates with severe invasive infections is the presence of a null mutant allele for the orphan kinase RocA. Through use of RNAseq analysis, we identified that the natural rocA mutation present within M3 isolates leads to the enhanced expression of more than a dozen immunomodulatory virulence factors, enhancing phenotypes such as hemolysis and NAD⁺ hydrolysis. Consequently, an M3 GAS isolate survived human phagocytic killing at a level 13‐fold higher than a rocA complemented derivative, and was significantly more virulent in a murine bacteremia model of infection. Finally, we identified that RocA functions through the CovR/S two‐component system as levels of phosphorylated CovR increase in the presence of functional RocA, and RocA has no regulatory activity following covR or covS mutation. Our data are consistent with RocA interfacing with the CovR/S two‐component system, and that the absence of this activity in M3 GAS potentiates the severity of invasive infections caused by isolates of this serotype.