Search

The article discusses glacier melting in the Himalayas has created thousands of such lakes, posing the risk of outburst floods. Topics include ‘polyhydroxybutyrate has usually produced using bacteria like Pseudodonghicola and Bacillus coagulans; and the researchers found about 161 of the 2424 lakes have stable, mostly in the ablation area.

Reverse-transcription quantitative real-time PCR (RT-qPCR), a sensitive technique is being extensively employed in quantification of gene expression. However this requires normalization with suitable reference gene (RG) which is crucial in minimizing inter sample variations. Information regarding suitable RG is scarce in general and more so in insects, including the cotton bollworm, Helicoverpa armigera, an economically important pest. In management of this pest RNA interference (RNAi) is perceived as a potential tool, which is achieved by double-stranded RNA (dsRNA) delivery. These studies demand accurate quantification of gene silencing. In this study we assessed the suitability of five RGs viz. β-actin ( ACTB), 18S rRNA ( 18S), glyceraldehyde-3-phosphate dehydrogenase ( GAPDH), β-tubulin ( TUB) and elongation fator-1-alfa ( EF1-α) for gene expression studies in dsRNA treatment and across different developmental stages of H. armigera and ranked using geNorm, NormFinder and BestKeeper software programs. Data analysis revealed that best ranked RGs were varied in dsRNA treatment and in developmental stages. Under dsRNA treatment, 18S and GAPDH were more stable whereas, TUB and GAPDH were more stable across developmental stages. We also demonstrate that inappropriate selection of RG led to erroneous estimation of the target gene, chymotrypsin expression. These results facilitate accurate quantification of gene expression in H. armigera. [ABSTRACT FROM AUTHOR]

The cotton bollworm, Helicoverpa armigera is a highly polyphagous pest infesting a number of economically important crops, annually causing enormous crop losses. Management of this pest is challenging over the years due to various factors including development of resistance to wide spectrum of chemical insecticides. RNA interference (RNAi) has tremendous potential to combat insect pests. However, RNAi mediated silencing efficiency varies from gene to gene, hence successful RNAi mediated pest control requires selection of suitable target gene(s), which are effectively silenced by the exogenous delivery of cognate double-stranded RNA (dsRNA) through midgut. Therefore, we have evaluated the effect of two concentrations of dsRNA delivered through semi-synthetic diet in silencing five important genes, viz. glutathione-S-transferase, cytochrome P450 (both involved in detoxification of host allelochemicals); trypsin, chymotrypsin (both involved in digestion of proteins) and juvenile hormone acid methyl transferase ( jhamt) (involved in larval metamorphosis). Extent of silencing was assessed by quantitative real-time PCR (qRT-PCR). Results revealed that above target genes were silenced variably, 20 μg dsRNA treatment having a more pronounced effect than 10 μg in reducing the transcript levels, larval, pupal weight, and pupation. Silencing of chymotrypsin had a more pronounced effect on larval and pupal weight compared to other target genes, while jhamt severely affected pupation. This study demonstrated that target genes have varied sensitivity to RNAi, chymotrypsin, and jhamt were shown to be suitable candidate genes that could be utilized for RNAi mediated management of H. armigera. [ABSTRACT FROM AUTHOR]

Transgenic tomato plants accumulating high amounts (70-100 fold) of anthocyanin in the fruit were developed by the fruit specific expression of two transcription factors, Delila and Rosea1 isolated from Antirrhinum majus. The transgenic tomato plants were identical to the control plants, except for the accumulation of high levels of anthocyanin pigments throughout the fruit during maturity, thus giving the fruit a purplish colour. The total carotenoids, including lycopene levels were unaffected in the anthocyanin-rich fruits, while its antioxidant capacity was elevated. The gene expression analysis confirmed the elevated expression of the downstream genes of the anthocyanin pathway due to the expression of the transcription factors and the expression levels coincided with the fruit ripening stages, highest expression occurring during the breaker stage. Anthocyanin-rich tomato fruit is important in view of the protective function of these compounds on consumption against a number of lifestyle-related diseases. [ABSTRACT FROM AUTHOR]

Abstract: Double-stranded RNA-mediated RNA interference in plants involves generating a construct expressing intron-containing hairpin RNA (ihpRNA), which usually is a cumbersome, multistep process. Here, we describe a simplified method involving single steps of PCR, restriction, ligation, and transformation for assembling an ihpRNA construct for plant transformation. Our method has several advantages over the currently available ones, viz., wider choice of restriction sites and facility for rapid screening of positive clones, among others. We demonstrate the utility of this approach in assembling the tomato phytoene desaturase gene. This simplified DNA fragment assembly strategy for ihpRNA construction facilitates high-throughput gene silencing in plants. [Copyright &y& Elsevier]

Abstract: We developed a modified polymerase chain reaction (PCR) primer with 3′ phosphate instead of hydroxyl group for single-tube accurate transcript quantification. 18S ribosomal RNA (rRNA) reference gene-specific modified primer was used for precise single-tube quantification of two target transcripts, namely chymotrypsin and jhamt (juvenile hormone acid methyl transferase) of Helicoverpa armigera. A comparative study of 3′ phosphorylated primers, 3′ mismatched primers, and commercial Competimers revealed that 3′ phosphorylation was more efficient than the 3′ mismatch and was on par with Competimers in blocking the primer extension. Thus, the modified primers can be used in single-tube, economical, and accurate PCR quantification of the target gene using any assay-specific reference gene. [Copyright &y& Elsevier]

The article offers briefs related to Indian Academy of Sciences. Topics include Hornbill Plateau in the Namdapha Tiger Reserve, Arunachal Pradesh is so named due to the high abundance of hornbills there; and north Indian Ocean basin, especially the Bay of Bengal, is a hot spot for frequent tropical cyclones, and early detection of cyclones in the region can save lives and reduce impact.

Helicoverpa armigera (the cotton bollworm) is a significant agricultural pest endemic to Afro-Eurasia and Oceania. Gene suppression via RNA interference (RNAi) presents a potential avenue for management of the pest, which is highly resistant to traditional insecticide sprays. This article reviews current understanding on the fate of ingested double-stranded RNA in H. armigera . Existing in vivo studies on diet-delivered RNAi and their effects are summarized and followed by a discussion on the factors and hurdles affecting the efficacy of diet-delivered RNAi in H. armigera . [ABSTRACT FROM AUTHOR]