Interspecific rice hybrid of Oryza sativa x Oryza nivara reveals a significant increase in seed protein content

Wild species offer a potential reservoir of genetic variation for crop improvement. Besides the valuable genes for disease resistance that the wild species have provided for rice improvement, recent studies have shown that these wild species could also provide favorable alleles for the improvement of yield and yield-related traits. The present study reports yet another potential of wild relatives of rice, which involves the improvement of seed protein content. A significant increase in seed protein content was observed in an interspecific hybrid between Oryza sativa ssp. indica and the wild species Oryza nivara. The hybrid showed a protein content of 12.4%, which was 28 and 18.2% higher than those of the parents O. nivara and IR 64, respectively. The increase in protein content was dependent on the genetic background of the rice variety used in the hybridization. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of seed storage proteins demonstrated that a significant increase in prolamins and glutelins was mainly responsible for the elevated protein content of the hybrid. Amino acid analysis of seed proteins revealed that the hybrid had net gains of 19.5% in lysine and 19.4% in threonine over the O. nivara parent on a seed dry weight basis. Molecular analysis indicated that the increase in protein content of the hybrid was not a result of chromosomal rearrangements or transposable element activation, at least in the chromosomal regions containing seed storage protein genes. A preliminary genetic analysis of the F 2 segregating population showed that the inheritance of the increased protein content was polygenic in nature. The development of this interspecific hybrid offers a great potential for selecting new rice cultivars that combine the high yield and superior cooking quality of IR 64 with improved seed protein content.     

Environmental Arsenic and Selenium Contamination and Approaches Towards Its Bioremediation Through the Exploration of Microbial Adaptations: A Review

Bioaccumulation of selenium and arsenic resulting from geogenic activities and aggravated by anthropogenic actions has now become a serious environmental issue. Different parts of the world are experiencing issues of selenium and arsenic contamination, especially in soil and groundwater. The present selenium and arsenic contamination scenario has been well represented in contemporary literature, and there are an array of remediation techniques targeting the decontamination of environmental contamination. The use of microbe-mediated remediation of selenium and arsenic contamination is gaining scientific attention for sustainable environmental bioremediation. The present review elucidates the different aspects of selenium and arsenic contamination, bioaccumulation, and bioremediation with implications for successful decontamination of these heavy metals.     

New pesticide metal complexes for controlled release

Six new pesticide metal complexes were synthesised, characterised and evaluated for controlled release by chemical and bioassay methods. Chemical assay and bioassay data demonstrate the increased persistence and increased shelf life of the pesticides upon complexation.     

Antibacterial and antifungal activities of Trewia polycarpa roots

The total alcoholic extract, its chloroform soluble and aqueous fractions of the roots of the plant Trewia polycarpa exhibited varying degrees of antibacterial and antifungal activities when tested with six bacterial and four fungal strains.     

Climate change impacts on plant canopy architecture: implications for pest and pathogen management

Climate change influences on pests and pathogens are mainly plant-mediated. Rising carbon dioxide and temperature and altered precipitation modifies plant growth and development with concomitant changes in canopy architecture, size, density, microclimate and the quantity of susceptible tissue. The modified host physiology and canopy microclimate at elevated carbon dioxide influences production, dispersal and survival of pathogen inoculum and feeding behaviour of insect pests. Elevated temperature accelerates plant growth and developmental rates to modify canopy architecture and pest and pathogen development. Altered precipitation affects canopy architecture through either drought or flooding stress with corresponding effects on pests and pathogens. But canopy-level interactions are largely ignored in epidemiology models used to project climate change impacts. Nevertheless, models based on rules of plant morphogenesis have been used to explore pest and pathogen dynamics and their trophic interactions under elevated carbon dioxide. The prospect of modifying canopy architecture for pest and disease management has also been raised. We offer a conceptual framework incorporating canopy characteristics in the traditional disease triangle concept to advance understanding of host-pathogen-environment interactions and explore how climate change may influence these interactions. From a review of recent literature we summarize interrelationships between canopy architecture of cultivated crops, pest and pathogen biology and climate change under four areas of research: (a) relationships between canopy architecture, microclimate and host-pathogen interaction; (b) effect of climate change related variables on canopy architecture; (c) development of pests and pathogens in modified canopy under climate change; and (d) pests and pathogen management under climate change.     

Independent molecular pathways in initiation and loss of hormone responsiveness of breast carcinomas

These studies were set up to determine whether those oncogenes participating in the initiation of mammary carcinogenesis (for example, ras oncogenes) play a direct role in the outcome of events associated with the late stages of tumor development such as loss of hormone dependency. Mammary carcinomas induced by a single carcinogenic insult in pubescent rats was selected as an in vivo model system with direct relevance to human breast cancer. Acquisition of hormone-independent growth in these carcinogen-induced tumors was found to be independent of the activation of ras oncogenes during the early stages of carcinogenesis. In agreement with these observations, introduction of a human ras oncogene into human MCF-7 breast carcinoma cells did not abrogate their hormonal dependency for growth in vivo. These findings suggest that those events responsible for the critical stages of breast cancer development occur independently and in an uncoordinated manner.     

The glycerinated body wall of the sea cucumber as a suitable preparation for electron microscopic and physiological studies of ‘catch mechanism’

ABSTRACT:   The body wall of the sea cucumber changes its stiffness by ionic environments. The stiff state can be held for a long time, and the mechanism concerned is known as 'catch mechanism'. In the present study, the direct effects of ions on the mechanism using the glycerinated body wall treated with 50% glycerin to clarify how the ions effect changes of stiffness were examined. The glycerinated body walls contained collagen fibers and some broken cells in the connective tissue ultrastructurally. Cell membranes were not clearly present in the broken cells, and cell organelles were dispersed around the cells. The glycerinated body walls went into a limp state during addition of 10 mM ethylenediaminetetraacetic acid (EDTA), and showed height elongation rate in this study's experimental system. In contrast, the elongation rate decreased by the addition of 10 mM CaCl₂, that is, the body wall came to a stiff state. This stiff state could be considered as equivalent to 'catch state' of glycerinated body wall. Collagen fibers in those samples showed more compact arrangements at 10 mM CaCl₂ treatment than the one of 10 mM EDTA ultrastructurally. These features and physiological results suggested that EDTA and/or CaCl₂ from outside affect directly to the main part of the 'catch' mechanism in the glycerinated body wall.     

Antipyretic, antinociceptive and anti-inflammatory activity of Premna herbacea roots

The alcoholic extract of the roots of Premna herbacea was investigated for its antipyretic, antinociceptive and anti-inflammatory potential in animal models. The extract, when administered orally to mice has been found to be safe up to a dose of 8.0 g/kg. A significant antipyretic effect has been observed in rabbits while mild antinociceptive effects were evidenced in mice when tested by chemical as well as thermal methods. The extract did not exhibit any anti-inflammatory activity in acute but significantly reduced the chronic inflammation.