Cyanobacterial diversity shifts induced by butachlor in selected Indian rice fields in Eastern Uttar Pradesh and Western Bihar analyzed with PCR and DGGE

The present study examines the effects of 30 mg/kg butachlor on the cyanobacterial diversity of rice fields in Eastern Uttar Pradesh and Western Bihar in India. A total of 40 samples were grouped into three classes [(i) acidic, (ii) neutral, and (iii) alkaline soils], based on physicochemical and principle component analyses. Acidic soils mainly harbored Westillopsis, Trichormus, Anabaenopsis, and unicellular cyanobacteria; whereas Nostoc, Anabaena, Calothrix, Tolypothrix, and Aulosira were found in neutral and alkaline soils. Molecular characterization using 16S rRNA PCR and DGGE revealed the presence of 13 different phylotypes of cyanobacteria in these samples. Butachlor treatment of the soil samples led to the disappearance of 5 and the emergence of 2 additional phylotypes. A total of 40 DGGE bands showed significant reproducible changes upon treatment with butachlor. Phylogenetic analyses divided the phylotypes into five major clusters exhibiting interesting links with soil pH. Aulosira, Anabaena, Trichormus, and Anabaenopsis were sensitive to butachlor treatment, whereas uncultured cyanobacteria, a chroococcalean member, Westillopsis, Nostoc, Calothrix, Tolypothrix, Rivularia, Gloeotrichia, Fischerella, Leptolyngbya, and Cylindrospermum, appeared to be tolerant against butachlor at their native soil pH. Butachlor-induced inhibition of nitrogen fixation was found to be 65% (maximum) and 33% (minimum) in the soil samples of pH 9.23 and 5.20, respectively. In conclusion, low butachlor doses may prove beneficial in paddy fields having a neutral to alkaline soil pH.     

Overexpression of HVA1 gene from barley generates tolerance to salinity and water stress in transgenic mulberry (Morus indica)

Late embryogenesis abundant (LEA) proteins are members of a large group of hydrophilic proteins found primarily in plants. The barley hva1 gene encodes a group 3 LEA protein and is induced by ABA and water deficit conditions. We report here the over expression of hva1 in mulberry under a constitutive promoter via Agrobacterium-mediated transformation. Molecular analysis of the transgenic plants revealed the stable integration and expression of the transgene in the transformants. Transgenic plants were subjected to simulated salinity and drought stress conditions to study the role of hva1 in conferring tolerance. The transgenic plants showed better cellular membrane stability (CMS), photosynthetic yield, less photo-oxidative damage and better water use efficiency as compared to the non-transgenic plants under both salinity and drought stress. Under salinity stress, transgenic plants show many fold increase in proline concentration than the non-transgenic plants and under water deficit conditions proline is accumulated only in the non-transgenic plants. Results also indicate that the production of HVA1 proteins helps in better performance of transgenic mulberry by protecting membrane stability of plasma membrane as well as chloroplastic membranes from injury under abiotic stress. Interestingly, it was observed that hva1 conferred different degrees of tolerance to the transgenic plants towards various stress conditions. Amongst the lines analysed for stress tolerance transgenic line ST8 was relatively more salt tolerant, ST30, ST31 more drought tolerant, and lines ST11 and ST6 responded well under both salinity and drought stress conditions as compared to the non-transgenic plants. Thus hva1 appears to confer a broad spectrum of tolerance under abiotic stress in mulberry.     

Pesticides induced changes in circulating thyroid hormones in the freshwater catfish Clarias batrachus.

1. Effects of endosulfan, malathion and carbaryl on circulating T4, T3 and T3/T4 ratio in the freshwater catfish, C. batrachus have been studied during reproductively active phases, i.e. vitellogenic and post-vitellogenic phases of its annual reproductive cycle. 2. Endosulfan provoked a significant increase in T4 and a decrease in T3 as well as the T3/T4 ratio. 3. Malathion decreased T3 and T3/T4 ratio without altering the level of T4 in circulation. 4. Carbaryl caused a decline in the level of T4 and an elevation in T3 and T3/T4 ratio.     

Oncogene-induced telomere dysfunction enforces cellular senescence in human cancer precursor lesions

In normal human somatic cells, telomere dysfunction causes cellular senescence, a stable proliferative arrest with tumour suppressing properties. Whether telomere dysfunction-induced senescence (TDIS) suppresses cancer growth in humans, however, is unknown. Here, we demonstrate that multiple and distinct human cancer precursor lesions, but not corresponding malignant cancers, are comprised of cells that display hallmarks of TDIS. Furthermore, we demonstrate that oncogenic signalling, frequently associated with initiating cancer growth in humans, dramatically affected telomere structure and function by causing telomeric replication stress, rapid and stochastic telomere attrition, and consequently telomere dysfunction in cells that lack hTERT activity. DNA replication stress induced by drugs also resulted in telomere dysfunction and cellular senescence in normal human cells, demonstrating that telomeric repeats indeed are hypersensitive to DNA replication stress. Our data reveal that TDIS, accelerated by oncogene-induced DNA replication stress, is a biological response of cells in human cancer precursor lesions and provide strong evidence that TDIS is a critical tumour suppressing mechanism in humans.     

The Horyzons project: a randomized controlled trial of a novel online social therapy to maintain treatment effects from specialist first‐episode psychosis services

This study aimed to determine whether, following two years of specialized support for first‐episode psychosis, the addition of a new digital intervention (Horyzons) to treatment as usual (TAU) for 18 months was more effective than 18 months of TAU alone. We conducted a single‐blind randomized controlled trial. Participants were people with first‐episode psychosis (N=170), aged 16‐27 years, in clinical remission and nearing discharge from a specialized service. They were randomly assigned (1:1) to receive Horyzons plus TAU (N=86) or TAU alone (N=84) between October 2013 and January 2017. Horyzons is a novel, comprehensive digital platform merging: peer‐to‐peer social networking; theory‐driven and evidence‐informed therapeutic interventions targeting social functioning, vocational recovery and relapse prevention; expert clinician and vocational support; and peer support and moderation. TAU involved transfer to primary or tertiary community mental health services. The primary outcome was social functioning at 18 months as measured by the Personal and Social Performance Scale (PSP). Forty‐seven participants (55.5%) in the Horyzons plus TAU group logged on for at least 6 months, and 40 (47.0%) for at least 9 months. Social functioning remained high and stable in both groups from baseline to 18‐month follow‐up, with no evidence of significant between‐group differences (PSP mean difference: –0.29, 95% CI: –4.20 to 3.63, p=0.77). Participants in the Horyzons group had a 5.5 times greater increase in their odds to find employment or enroll in education compared with those in TAU (odds ratio, OR=5.55, 95% CI: 1.09‐28.23, p=0.04), with evidence of a dose‐response effect. Moreover, participants in TAU were twice as likely to visit emergency services compared to those in the Horyzons group (39% vs. 19%; OR=0.31, 95% CI: 0.11‐0.86, p=0.03, number needed to treat, NNT=5). There was a non‐significant trend for lower hospitalizations due to psychosis in the Horyzons group vs. TAU (13% vs. 27%; OR=0.36, 95% CI: 0.11‐1.08, p=0.07, NNT=7). So, although we did not find a significant effect of Horyzons on social functioning compared with TAU, the intervention was effective in improving vocational or educational attainment, a core component of social recovery, and in reducing usage of hospital emergency services, a key aim of specialized first‐episode psychosis services. Horyzons holds significant promise as an engaging and sustainable intervention to provide effective vocational and relapse prevention support for young people with first‐episode psychosis beyond specialist services.     

Description of a new congrid eel,Ariosoma albimaculata sp. nov. (Anguilliformes: Congridae), from the southwest coast of India,Arabian Sea

Ichthyological Research - Ariosoma albimaculata sp. nov. is described herein based on ten specimens [240–487 mm total length (TL)] collected from the deep-sea trawl landings at Colachel...     

Identification of a major QTL allele from wild soybean (Glycine soja Sieb. & Zucc.) for increasing alkaline salt tolerance in soybean

Salt-affected soils are generally classified into two main categories, sodic (alkaline) and saline. Our previous studies showed that the wild soybean accession JWS156-1 (Glycine soja) from the Kinki area of Japan was tolerant to NaCl salt, and the quantitative trait locus (QTL) for NaCl salt tolerance was located on soybean linkage group N (chromosome 3). Further investigation revealed that the wild soybean accession JWS156-1 also had a higher tolerance to alkaline salt stress. In the present study, an F₆ recombinant inbred line mapping population (n = 112) and an F₂ population (n = 149) derived from crosses between a cultivated soybean cultivar Jackson and JWS156-1 were used to identify QTL for alkaline salt tolerance in soybean. Evaluation of soybean alkaline salt tolerance was carried out based on salt tolerance rating (STR) and leaf chlorophyll content (SPAD value) after treatment with 180 mM NaHCO₃ for about 3 weeks under greenhouse conditions. In both populations, a significant QTL for alkaline salt tolerance was detected on the molecular linkage group D2 (chromosome 17), which accounted for 50.2 and 13.0% of the total variation for STR in the F₆ and the F₂ populations, respectively. The wild soybean contributed to the tolerance allele in the progenies. Our results suggest that QTL for alkaline salt tolerance is different from the QTL for NaCl salt tolerance found previously in this wild soybean genotype. The DNA markers closely associated with the QTLs might be useful for marker-assisted selection to pyramid tolerance genes in soybean for both alkaline and saline stresses.     

Genetic engineering approaches to enhance oil content in oilseed crops

Oilseed crops play an important role in the agricultural economy. Apart from being an integral component of human diet and industrial applications, they are also gaining importance as replacement to fossil fuels for meeting the energy needs. The last two decades have been marked by several important events in genetic engineering and identification of gene targets for enhancing seed oil content in oilseed crops, and will aid the successful development of new generation high yielding oil crops. Specifically, genetic engineering has shown real breakthrough in enhancing oil content in oilseed rape, camelina, soybean and maize. Moreover, ongoing research efforts to decipher the possibilities of genetic modifications of key regulators of oil accumulation along with physiological and biochemical studies to understand lipid biosynthesis will set a platform to produce transgenic oilseed crops with enhanced oil content. In this review, we briefly describe different genetic engineering approaches explored by different researchers for enhancing oil content. Further, we discuss a few promising and potential approaches and challenges for engineering oil content in oilseed crops.     

Airborne and belowground phytotoxicity of invasive Ageratina adenophora on native species in Nepal

Plant Ecology - Volatile compounds from leaf litter of invasive alien Ageratina adenophora are known to inhibit growth of native species in sub-tropical Asia, but there is not...     

Induction of hsp70, alterations in oxidative stress markers and apoptosis against dichlorvos exposure in transgenic Drosophila melanogaster: Modulation by reactive oxygen species

We examined a hypothesis that reactive oxygen species (ROS) generated by organophosphate compound dichlorvos modulates Hsp70 expression and anti-oxidant defense enzymes and acts as a signaling molecule for apoptosis in the exposed organism. Dichlorvos (0.015–15.0 ppb) without or with inhibitors of Hsp70, superoxide dismutase (SOD) and catalase (CAT) were fed to the third instar larvae of Drosophila melanogaster transgenic for hsp70 (hsp70-lacZ) Bg⁹ to examine Hsp70 expression, oxidative stress and apoptotic markers. A concentration- and time-dependent significant increase in ROS generation accompanied by a significant upregulation of Hsp70 preceded changes in antioxidant defense enzyme activities and contents of glutathione, malondialdehyde and protein carbonyl in the treated organisms. An inhibitory effect on SOD and CAT activities significantly upregulated ROS generation and Hsp70 expression in the exposed organism while inhibition of Hsp70 significantly affected oxidative stress markers induced by the test chemical. A comparison made among ROS generation, Hsp70 expression and apoptotic markers showed that ROS generation is positively correlated with Hsp70 expression and apoptotic cell death end points indicating involvement of ROS in the overall adversity caused by the test chemical to the organism. The study suggests that (a) Hsp70 and anti-oxidant enzymes work together for cellular defense against xenobiotic hazard in D. melanogaster and (b) free radicals may modulate Hsp70 expression and apoptosis in the exposed organism.