Transcription Factors and MicroRNA Interplay: A New Strategy for Crop Improvement

MicroRNAs (miRNAs) and transcription factors are master regulators of the cellular system. Plant genomes contain thousands of protein-coding and non-coding RNA genes; which are differentially expressed in different tissues at different times during growth and development. Complex regulatory networks that are controlled by transcription factors and microRNAs, which coordinate gene expression. Transcription factors, the key regulators of plant growth and development, are the targets of the miRNAs families. The combinatorial regulation of transcription factors and miRNAs guides the appropriate implementation of biological events and developmental processes. The resources on the regulatory cascades of transcription factors and miRNAs are available in the context of human diseases, but these resources are meager in case of plant diseases. On the other hand, it is also important to understand the cellular and physiological events needed to operate the miRNAs networks. The relationship between transcription factors and miRNA in different plant species described in this chapter will be of great interest to plant scientists, providing better insights into the mechanism of action and interactions among transcription factors (TFs) and miRNA networks culminating in improving key agronomic traits for crop improvement to meet the future global food demands

EST-SSRs Provide a Good Measure of Genetic Diversity for Improvement of Gum Content in Cluster Bean

Cyamopsis tetragonoloba (L.) Taub., commonly known as guar is an important multipurpose arid leguminous crop of India, mainly cultivated in north-western parts of India. The pods of the guar plant grow in clusters giving guar the common name of clusterbean. It is mainly grown for feed, green fodder, vegetable and green manuring. Its seeds are also an important source of galactomannan (guar gum) which is used as a food ingredient and more recently as a neutraceutical. Guar gum is also having pharmaceutical importance and found to be effective in osteoarthritis, as artificial cervical mucus and for anticancer medicine in the treatment of colorectal cancer. Particularly in 2012, world demand for guar gum has skyrocketed and the price of guar has increased by approximately 230 per cent and even more, mainly because of increased oilfield shale gas demand. As a consequence, there has been a 75 per cent jump in exports from India, the largest guar producing country (Gresta et al., 2013) due to which India’s much neglected and little-known galactomannan became its biggest agricultural item of export. To fulfill all these purposes, the increasing demand of the guar seeds cannot be compensated by present resources. Therefore, new varieties with higher gum content are urgently needed. For this, knowledge of genetic diversity among the varieties has immense importance for plant breeders. Larger variability in the initial breeding material ensures better chances of producing new desired forms of a crop (Pathak et al., 2011). Molecular markers offer a promising tool for plant breeding efforts. SSRs are highly valued molecular markers for studying genetic diversity in crop plants. But unfortunately, clusterbean is a genomically poor crop as no genomic SSRs have been developed. Literature available on the nature and magnitude of diversity in clusterbean indicates that the studies of this kind are scanty and not properly documented. Studies were therefore, required to assess the extent of genetic variability in association with the galactomannan content using reliable EST-SSRs

Toxicity Assessment of Nickel Nitrate and Effect on Total Leucocyte Count in Albino Rat

Heavy metals contribute a variety of adverse health effects. There are over 20 different heavy metal toxins that can impact health effects and each toxin produces different behavioural and physiological misconduct in an exposed individual. Heavy metals have bioimportance as trace element but the biotoxic effects of many of them in human biochemistry are of great concern. Hence, there is a need for understanding of the conditions such as concentration and oxidation states which make them harmful and how biotoxicity occurs. Nickel nitrate affects body physiology following its absorption through food, water and air. Predetermined doses of nickel nitrate (Ni(NO3)2] in acute (1d) and subacute (7, 14, 21, 28ds) treatments revealed significant increase in total leucocyte count (TLC). The results indicate extent of toxicity and enhancement in total leucocyte count under toxic stress of nickel nitrate in albino rat

Toxicological Profile of Aluminium Sulphate and Effect on Protein Profile in Albino Rat

World is full of xenobiotic substances such as heavy metal, pesticide and other pollutic agents. Heavy metal is a metallic element of relatively high density greater than 4gm/cm3 or 5 times more greater than water and is toxic even at low concentration. Heavy metals occur as a natural constituent of earth crust, can be emitted into environment by both natural and anthropogenic causes. Major cause of emission is the mining operations. Predetermined doses of aluminium sulphate in acute (1d) and subacute (7, 14, 21, 28ds) treatments revealed significant increase in albumin and globulin. The results are encouraging and highlight the toxic profile of aluminum sulphate and its effect on protein profile in albino rat

Low-mass young stellar population and star formation history of the cluster IC 1805 in the W4 H{\sc ii} region

W4 is a giant H{\sc ii} region ionized by the OB stars of the cluster IC~1805. The H{\sc ii} region/cluster complex has been a subject of numerous investigations as it is an excellent laboratory for studying the feedback effect of massive stars on the surrounding region. However, the low-mass stellar content of the cluster IC~1805 remains poorly studied till now. With the aim to unravel the low-mass stellar population of the cluster, we present the results of a multiwavelength study based on deep optical data obtained with the Canada-France-Hawaii Telescope, infrared data from 2MASS, $Spitzer$ Space Telescope and X-ray data from $Chandra$ Space Telescope. The present optical dataset is complete enough to detect stars down to 0.2~M$_\odot$, which is the deepest optical observations so far for the cluster. We identified 384 candidate young stellar objects (YSOs; 101 Class I/II and 283 Class III) within the cluster using various colour-colour and colour-magnitude diagrams. We inferred the mean age of the identified YSOs to be $\sim$ 2.5 Myr and mass in the range 0.3 - 2.5 M$_\odot$. The mass function of our YSO sample has a power law index of -1.23 $\pm$ 0.23, close to the Salpeter value (-1.35), and consistent with those of other star-forming complexes. We explored the disk evolution of the cluster members and found that the diskless sources are relatively older compared to the disk bearing YSO candidates. We examined the effect of high-mass stars on the circumstellar disks and found that within uncertainties, the influence of massive stars on the disk fraction seems to be insignificant. We also studied the spatial correlation of the YSOs with the distribution of gas and dust of the complex to conclude that IC 1805 would have formed in a large filamentary cloud.Comment: Accepted for publication in MNRAS; 34 pages, 10 figure

Plant regeneration and Agrobacterium-mediated transformation in Indian mustard (Brassica juncea)

Abstract Using seedling explants, a highly efficient and reproducible plant regeneration and transformation system was developed in Brassica juncea genotypes RH-406 and RH-555. Hypocotyl and cotyledon explants excised from in vitro-grown 5-days-old seedlings were cultured on MS medium supplemented with different concentrations and combinations of growth regulators. Cotyledon explants grown on MS medium supplemented with 1 and 2.5 mg/L BAP produced higher per cent shoot formation in genotypes RH-555 (60.3±4.19) and RH-406 (64.9± 1.42), respectively. Among the eight rooting media used for root formation in regenerated shoots, maximum rooting response was obtained on MS medium supplemented with 0.2 mg/L NAA. Among the regenerated plants, 81.8 % in RH-406 and 67% in RH-555 survived when transferred on sand and soil in 1:1 mixture in pots. Transformation protocol was developed in genotype RH-406 using GUS reporter gene and hypocotyls and cotyledon explants. Histochemical GUS assay showed that cotyledon and hypocotyl explants respectively, had 75% and 80% transient GUS expressions

Agrotags – A tagging scheme for agricultural digital objects

Keyword assignment is an important step towards semantic enablement of the web. In this paper we describe a taxonomy called Agrotags which is designed for tagging agriculture documents. Agrotags is a subset of Agrovoc and is much smaller: about 2100 as against 40,000. Agrotags is manually created by carefully examining each of the Agrovoc terms for their utility in tagging. This selected subset is further refined and validated by looking at the manually assigned keywords from Agris databases. Further extending the usage of Agrotags emerges the concept of Agrotagger which is a system for automatically generating keywords for agricultural documents. Agrotagger has been built by moving the learning (what keyword to assign) from the example (document) level to the model level. Agrotagger being a pluggable module can act as an add-on to any repositor

Post-outburst evolution of bonafide FUor V2493 Cyg: A Spectro-photometric monitoring

We present here the results of eight years of our near-simultaneous optical/near-infrared spectro-photometric monitoring of bonafide FUor candidate `V2493 Cyg' starting from 2013 September to 2021 June. During our optical monitoring period (between October 16, 2015 and December 30, 2019), the V2493 Cyg is slowly dimming with an average dimming rate of $\sim$26.6 $\pm$ 5.6 mmag/yr in V band. Our optical photometric colors show a significant reddening of the source post the second outburst pointing towards a gradual expansion of the emitting region post the second outburst. The mid infra-red colors, on the contrary, exhibits a blueing trend which can be attributed to the brightening of the disc due to the outburst. Our spectroscopic monitoring shows a dramatic variation of the H$\alpha$ line as it transitioned from absorption feature to the emission feature and back. Such transition can possibly be explained by the variation in the wind structure in combination with accretion. Combining our time evolution spectra of the Ca II infra-red triplet lines with the previously published spectra of V2493 Cyg, we find that the accretion region has stabilised compared to the early days of the outburst. The evolution of the O I $\lambda$7773 \AA~ line also points towards the stabilization of the circumstellar disc post the second outburst.Comment: 34 pages, 12 figures, 6 tables, accepted for publication in Ap

Regulation of the Fruit-Specific PEP Carboxylase SlPPC2 Promoter at Early Stages of Tomato Fruit Development

The SlPPC2 phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) gene from tomato (Solanum lycopersicum) is differentially and specifically expressed in expanding tissues of developing tomato fruit. We recently showed that a 1966 bp DNA fragment located upstream of the ATG codon of the SlPPC2 gene (GenBank AJ313434) confers appropriate fruit-specificity in transgenic tomato. In this study, we further investigated the regulation of the SlPPC2 promoter gene by analysing the SlPPC2 cis-regulating region fused to either the firefly luciferase (LUC) or the β-glucuronidase (GUS) reporter gene, using stable genetic transformation and biolistic transient expression assays in the fruit. Biolistic analyses of 5′ SlPPC2 promoter deletions fused to LUC in fruits at the 8th day after anthesis revealed that positive regulatory regions are mostly located in the distal region of the promoter. In addition, a 5′ UTR leader intron present in the 1966 bp fragment contributes to the proper temporal regulation of LUC activity during fruit development. Interestingly, the SlPPC2 promoter responds to hormones (ethylene) and metabolites (sugars) regulating fruit growth and metabolism. When tested by transient expression assays, the chimeric promoter:LUC fusion constructs allowed gene expression in both fruit and leaf, suggesting that integration into the chromatin is required for fruit-specificity. These results clearly demonstrate that SlPPC2 gene is under tight transcriptional regulation in the developing fruit and that its promoter can be employed to drive transgene expression specifically during the cell expansion stage of tomato fruit. Taken together, the SlPPC2 promoter offers great potential as a candidate for driving transgene expression specifically in developing tomato fruit from various tomato cultivars