Critical review on uranium and arsenic content and their chemical mobilization in the groundwater: A case study of the Malwa region Punjab, India

Groundwater played a pivotal role in the social and economic development of the Malwa Region. With the advent of the green revolution, water for irrigation and domestic use led to the development of groundwater resources. Slowly, the green revolution changed into a greed revolution, and the exploitation of groundwater resources converted into their overexploitation. Groundwater\u27s overexploitation not only led to groundwater depletion but also led to a change in the chemistry of the Malwa region\u27s aquifers. Researchers from academia and institutions worked and published their findings of the uranium and arsenic contaminations in the Malwa region of Punjab. In this article, we are the first to bring all the dispersed data to one commonplace. By studying the physicochemical parameters of groundwater of all districts of the Malwa region and their correlation, this paper is going to highlight the various chemical reactions occurring in the Malwa region\u27s aquifer and how they impact groundwater chemistry. For understanding, we devised a hypothetical model to understand the complex interplay of this region\u27s natural dynamics of groundwater aquifers. Finally, we tried to describe how the various chemical changes in the groundwater aquifer can be the reason for the mobilization of arsenic and uranium by making schematic chemical flow-charts of their mobilization. This article aims to highlight the importance of using a multidisciplinary and interdepartmental approach to comprehending the complex problem of groundwater management

<span style="font-size:11.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-bidi-font-family: Mangal;mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language: HI" lang="EN-GB">Assessment of <i style="mso-bidi-font-style:normal">Arabidopsis thaliana <span style="mso-bidi-font-style:italic">CENH3</span></i> promoter in <i style="mso-bidi-font-style:normal">Brassica juncea</i> for development of haploid inducer lines</span>

425-430<span style="font-size:11.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi;mso-bidi-font-weight:bold"="" lang="EN-GB">Centromeres are epigenetically specified by the centromeric histone H3 protein (CENH3). The timing and level of expression of CENH3 is tightly regulated to match the demands of the host cell. So far in plants, only CENH3 promoter of Arabidopsis thaliana (L.) Heynh. has been characterized. However, whether CENH3 promoters retain their characteristic mode of regulation in other species remains to be established. In the present study, activity of AtCENH3 promoter was investigated using reporter gene assay in <i style="mso-bidi-font-style: normal">Brassica juncea (L.) Czern. A 1156 bp promoter fragment of AtCENH3 gene (<i style="mso-bidi-font-style: normal">At1g01370) including the first 111 nucleotides of the coding sequence was amplified and cloned into the pORE-R2 binary vector to ensure translation fusion with the uidA coding sequences. The Agrobacterium tumefaciens strain GV3101 harbouring the recombinant construct was used to transform B. juncea cv. RLM198 hypocotyl explants. Histochemical assay of T0 and T1 transgenics showed GUS expression in shoot apical meristem, leaf, sepal, flower pedicel and root tip. Intense GUS expression was observed in meristematic tissues, particularly at shoot and root apices. However, mature leaves, flowers, pollen and ovules exhibited very low or no GUS expression. Our results showed that AtCENH3 promoter regulates cognate gene expression in Brassica juncea as it does in A. thaliana, and hence a suitable candidate for developing haploid inducer line in <i style="mso-bidi-font-style: normal">B. juncea. </span

Seed-specific Overexpression of Arabidopsis DGAT1 in Indian mustard (Brassica juncea) Increases Seed Oil and Seed Weight

Oil content is an important yield trait in B. juncea. Efforts to improve yield levels of mustard by conventional breeding methods have reached a plateau. Application of transgenic technology is an area that has not been explored for improving oil content in B. juncea. In this study, effect of overexpression ofAtDGAT1 (a key gene involved in oil biosynthesis) on seed oil content of B. juncea was investigated. For seed specific overexpression, the gene was linked to Arabidopsis thaliana oleosin promoter and mobilized into mustard through Agrobacterium-mediated transformation. Transformants were selected on MS medium containing 50 mg/l kanamycin, and a transformation frequency of 10.5% was obtained. A total of 10 transgenic events were generated. Analyses of seed weight, oil content and other yield traits in T1 transgenics showed that seed specific overexpression ofAtDGAT1 improved the oil content and seed weight significantly. The maximum seed oil content increase observed in transgenics was 8.3% compared to the wild type plants. Total fatty acid content was increased from4% to 14% in six of the seven events. However, oleic and linoleic acid contents were reduced and of these two, oleic acid content showed drastic reduction.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Cloning, characterization and expression analysis of <em>APETALA2</em> genes of <em>Brassica juncea</em> (L.) Czern.

604-610The APETALA2/Ethylene-Responsive Factor (AP2/ERF) is one of the largest gene families encoding several plant specific transcription factors. It plays significant roles in growth and development process, biotic and abiotic stresses, and responses to hormones. AP2 is a homeotic gene governing floral meristem specification, floral organ determination and floral homeotic gene expression in Arabidopsis. The basic structure of AP2 gene was unchanged during evolution in diploid species. The present study was undertaken to find whether AP2 has undergone any change in structure or expression pattern during evolution of allopolyploid Brassica juncea. We cloned AP2 orthologs and c-DNAs from B. juncea and B. nigra. B. juncea was found to carry three AtAP2 orthologs. Comparison of BjAP2 genes with AP2 orthologs from progenitor species, B. rapa and B. nigra showed that two of the BjAP2 genes were derived from B. rapa and one from B. nigra. BjAP2 genes have retained its characteristic AP2 domain and miR172 complementary sequences. mRNAs originated from three AP2 orthologs were detected in all the tissues examined, namely, leaf, flower buds and seedling, indicating absence of sub-functionalization of AP2 during polyploid evolution. However, one of the B. rapa copies gave alternatively spliced AP2 transcript which lacked the second exon. Consequently, the splice variant could not be translated into functional AP2 protein. Considering that miR172 suppresses translation of AP2 transcripts, the alternatively spliced transcript could still play important regulatory role by limiting the availability of miR172 molecules to bind to functional AP2 transcripts. qRT-PCR analysis of BjAP2 expression in different accessions of B. juncea with contrasting seed size indicated that BjAP2 is not a major determinant of seed size in mustard

High temperature compressive flow behavior and associated microstructural development in a β-stabilized high Nb-containing γ-TiAl based alloy

The characteristics of hot deformation behavior and associated microstructural development of a cast γ-TiAl based Ti-45Al-8Nb-2Cr-0.2B (at.%) alloy have been investigated in the temperature range of 1273–1473 K and the strain rate range of 0.5–0.005 s−1 using a Gleeble thermo-mechanical simulator. The as-cast pancake shows a uniform distribution of fine (α2+γ) and (γ+γ) lamellar colonies with intermittent retained β(B2) and γ grains (average volume fraction: γ = 0.89, α2 = 0.03, and β(B2) = 0.08). Hot deformation behavior has been characterized by detailed analyses of processing maps, Arrhenius type constitutive models, and microstructural evolution. The results indicate that the apparent activation energy (Q = 429 kJ/mol) measured through hyperbolic-sinusoidal relationship between flow stress, temperature and strain rate could be correlated to the dynamic recrystallization (DRX) and presence of lamellar (α2+γ) microstructure. Further, the morphological alignment of lamellae boundaries in conjunction with deformation temperature plays a crucial role in determining the DRX mechanism and controls the microstructural evolution. Dynamic recrystallization occurs preferentially in the grain boundary β-phases, and thereby, improves the workability of the alloy. It has been established that the β-phase assumes a “supplementary” role during hot deformation of TiAl alloys. A systematic variation in β-phase volume fraction indicates that the amount of retained β-phase along with its morphology plays an important role as it suppresses the crack initiation and/or propagation by absorbing the stress concentration arising during deformation of lamellar colonies in high Nb containing γ TiAl alloys

Hot deformation of high-Nb-containing γ-TiAl alloy in the temperature range of 1000–1200 °C: microstructural attributes to hot workability

Hot deformation behavior of a high-Nb-containing cast γ-TiAl-based Ti–45Al–8Nb (at.%) alloy has been investigated in the temperature range of 1000–1200 °C and the strain rate range of 0.5–0.005 s−1. The alloy shows an initial microstructure of coarse lamellar ((α2 + γ) and (γ + γ)) colonies. The effect of strain rate and temperature domain on hot deformability of the alloy has been analyzed through a correlation between the apparent activation energy, deformation process maps, and associated microtextural development. The relatively higher apparent activation energy (Q = 553.8 kJ/mol) could be correlated with the fully lamellar α2 + γ microstructure which posses greater resistance to the mobile dislocation. The results are further corroborated by the “instability-dominated” processing maps indicating poor hot deformability of the alloy in the studied temperature–strain rate range. Detailed electron microscopy of the deformed samples indicates that poor workability exhibited as cracks that are predominantly found at the coarse γ-TiAl grains situated at the lamellar boundaries. The crack initiation and propagation mechanisms during hot compression have further been discussed with reference to concurrent dynamic recrystallization. It has been found that “wedge-type” cavitation damage is prevalent during compressive deformation in the temperature range studied here. Such cracking behavior is elucidated in light of the “Semiatin–Seetharaman criterion.

Genotypic diversity and abiotic stress response profiling of short-grain aromatic landraces of rice (Oryza sativa L. Indica)

This study evaluated the physiological responses and genetic diversity of selected short-grain aromatic rice landraces of Northern Eastern Ghats of India to multiple abiotic stresses. Results revealed that drought, salt and flooding stress remarkably declined plant biomass, relative growth index (RGI), relative water content (RWC), leaf photosynthesis, PSII activity, SPAD relative index, and elevated effect was found in susceptible IR64 (susceptible check) variety. We employed molecular marker analysis to characterize 21 rice genotypes using 32 SSR primers related to drought, flooding and salinity tolerance QTLs. Our analysis suggests significantly high polymorphism (93.12%) in 96 loci. The mean value of polymorphism information content (PIC), marker index (MI) and resolving power (RP) and heterozygosity index (HI) were 0.326, 1.037, 1.558 and 0.420 respectively. The Jaccard’s similarity coefficient ranged from 0.158 to 0.846 with a mean genetic dissimilarity of 0.647. According to neighbor-joining method of clustering, all genotypes were grouped into two major and five sub-clusters which is concurrent with a very broad genetic base (K = 5) obtained with STRUCTURE analysis. Taken together, six aromatic genotypes Basubhoga, Dudhamani, Kalajeera, Laktimachi, Kuyerkuling and Tulasi are genetically very close to drought-tolerant (N22) and flooding tolerant (FR13A) cultivar whereas, salt-tolerant (Pokkali) very close to Sapuri and Muktabali. The degree of genetic variants obtained from this profiling could be useful for landrace conservation, selection and global implications for multiple abiotic stress tolerance

Mutations in the mitochondrial <i>orf108</i> render <i>Moricandia arvensis</i> restorer ineffective in restoring male fertility to <i>Brassica oxyrrhina</i>-based cytoplasmic male sterile line of <i>B. juncea</i>

We reported earlier an evolutionarily conserved mitochondrial orf108 causing cytoplasmic male sterility (CMS) in four alloplasmic lines of Brassica juncea. B. oxyrrhina also carries orf108, but male sterility of B. oxyrrhina-based B. juncea CMS lines is not restored by the Moricandia arvensis restorer that rescues other orf108-containing B. juncea CMS lines. To understand this discrepancy, we characterized B. oxyrrhina-based B. juncea CMS line (oxy-cms) to identify the mitochondrial gene associated with male sterility. Examination of expression patterns of 26 mitochondrial genes in CMS and male fertile (oxy-camp, i.e. amphidiploid B. oxyrrhina × B. rapa, and euplasmic B. juncea) lines revealed polymorphic transcript patterns for six genes: atp1, atp4, ccmfn2, cox3, nad4L and orf108. Detailed analysis showed that orf108 is linked and co-transcribed with atp1. Comparison of orf108-atp1 transcripts in male sterile and male fertile flowers revealed that B. oxyrrhina restorer cleaves orf108-atp1 at a different location within the orf108 coding region as compared with the M. arvensis restorer. A total of eleven SNPs were detected within the orf108 coding region. One of these SNPs was located at the site where M. arvensis restorer processes the orf108-atp1 transcript suggesting that it could be critical for cleavage of orf108-atp1 transcript by the M. arvensis restorer.</p

Hot Deformation Behavior of γ-TiAl-Based Ti–45Al–8Nb–6Cr–0.2B Alloy in the γ + β Phase Field

The hot deformation behavior of a cast Ti–45Al–8Nb–6Cr–0.2B (at.%) alloy has been investigated in the temperature and strain rate range of 1000–1200 ℃ and 0.5–0.005 s−1, respectively, using a Gleeble thermo-mechanical simulator. The as-cast pancake shows a coarse distribution of γ-TiAl laths with irregular β(B2)-phase structure (average volume fraction: γ = 0.75 and β = 0.23). Characteristics of hot deformation have been evaluated through the correlation between Arrhenius type constitutive models, processing maps, and microstructural evolution. The apparent activation energy, measured through the hyperbolic-sinusoidal relationship between flow stress, temperature, and strain rate, has been found to be 282.90 kJ/mol. The significantly low activation energy is attributed to the absence of lamellar microstructure and high volume fraction of β(B2)-phase which aids deformation at higher temperatures. Microstructural evolution of the deformed samples indicates that the flow softening corresponds to the dynamic recrystallization (DRX). DRX has been found to occur preferentially in the coarse lath boundary of the TiAl phase and also within elongated β(B2)-grains. It has been shown that extensive DRX as a result of morphological characteristics of γ-phase together with a high volume fraction of β-phase facilitates high hot workability of the present alloy. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd