Vijay Gahlaut

Bio: Vijay Gahlaut is an academic researcher from University of Delhi. The author has contributed to research in topics: Biology & Medicine. The author has an hindex of 16, co-authored 35 publications receiving 691 citations. Previous affiliations of Vijay Gahlaut include Council of Scientific and Industrial Research & Chaudhary Charan Singh University.

Transcription factors involved in drought tolerance and their possible role in developing drought tolerant cultivars with emphasis on wheat (Triticum aestivum L.)

Abstract: TFs involved in drought tolerance in plants may be utilized in future for developing drought tolerant cultivars of wheat and some other crops. Plants have developed a fairly complex stress response system to deal with drought and other abiotic stresses. These response systems often make use of transcription factors (TFs); a gene encoding a specific TF together with -its target genes constitute a regulon, and take part in signal transduction to activate/silence genes involved in response to drought. Since, five specific families of TFs (out of >80 known families of TFs) have gained widespread attention on account of their significant role in drought tolerance in plants, TFs and regulons belonging to these five multi-gene families (AP2/EREBP, bZIP, MYB/MYC, NAC and WRKY) have been described and their role in improving drought tolerance discussed in this brief review. These TFs often undergo reversible phosphorylation to perform their function, and are also involved in complex networks. Therefore, some details about reversible phosphorylation of TFs by different protein kinases/phosphatases and the co-regulatory networks, which involve either only TFs or TFs with miRNAs, have also been discussed. Literature on transgenics involving genes encoding TFs and that on QTLs and markers associated with TF genes involved in drought tolerance has also been reviewed. Throughout the review, there is a major emphasis on wheat as an important crop, although examples from the model cereal rice (sometimes maize also), and the model plant Arabidopsis have also been used. This knowledge base may eventually allow the use of TF genes for development of drought tolerant cultivars, particularly in wheat.

QTL Analysis for Drought Tolerance in Wheat: Present Status and Future Possibilities

Abstract: In recent years, with climate change, drought stress has been witnessed in many parts of the world. In many irrigated regions also, shortage of water supply allows only limited irrigation. These conditions have an adverse effect on the productivity of many crops including cereals such as wheat. Therefore, genetics of drought/water stress tolerance in different crops has become a priority area of research. This research mainly involves use of quantitative trait locus (QTL) analysis (involving both interval mapping and association mapping) for traits that are related to water-use efficiency. In this article, we briefly review the available literature on QTL analyses in wheat for traits, which respond to drought/water stress. The outlook for future research in this area and the possible approaches for utilizing the available information on genetics of drought tolerance for wheat breeding are also discussed.

QTL mapping for nine drought-responsive agronomic traits in bread wheat under irrigated and rain-fed environments

Abstract: In bread wheat, QTL interval mapping was conducted for nine important drought responsive agronomic traits. For this purpose, a doubled haploid (DH) mapping population derived from Kukri/Excalibur was grown over three years at four separate locations in India, both under irrigated and rain-fed environments. Single locus analysis using composite interval mapping (CIM) allowed detection of 98 QTL, which included 66 QTL for nine individual agronomic traits and 32 QTL, which affected drought sensitivity index (DSI) for the same nine traits. Two-locus analysis allowed detection of 19 main effect QTL (M-QTL) for four traits (days to anthesis, days to maturity, grain filling duration and thousand grain weight) and 19 pairs of epistatic QTL (E-QTL) for two traits (days to anthesis and thousand grain weight). Eight QTL were common in single locus analysis and two locus analysis. These QTL (identified both in single- and two-locus analysis) were distributed on 20 different chromosomes (except 4D). Important genomic regions on chromosomes 5A and 7A were also identified (5A carried QTL for seven traits and 7A carried QTL for six traits). Marker-assisted recurrent selection (MARS) involving pyramiding of important QTL reported in the present study, together with important QTL reported earlier, may be used for improvement of drought tolerance in wheat. In future, more closely linked markers for the QTL reported here may be developed through fine mapping, and the candidate genes may be identified and used for developing a better understanding of the genetic basis of drought tolerance in wheat.

Hybrid wheat: past, present and future.

Abstract: The review outlines past failures, present status and future prospects of hybrid wheat, and includes information on CMS/CHA/transgenic approaches for male sterility, heterotic groups and cost-effective hybrid seed production. Hybrid varieties give increased yield and improved grain quality in both cross- and self-pollinated crops. However, hybrid varieties in self-pollinated crops (particularly cereals) have not been very successful, except for hybrid rice in China. In case of hybrid wheat, despite the earlier failures, renewed efforts in recent years have been made and hybrid varieties with desirable attributes have been produced and marketed in some European countries. This review builds upon previous reviews, with a new outlook and improved knowledge base, not covered in earlier reviews. New technologies have been described, which include the Hordeum chilense-based CMS–fertility restorer system, chromosomal XYZ-4E-ms system and the following transgenic technologies: (1) conditional male sterility involving use of tapetum-specific expression of a gene that converts a pro-toxin into a phytotoxin causing male sterility; (2) barnase-barstar SeedLink system of Bayer CropScience; (3) split-barnase system that obviates the need of a barstar-based male restorer line; and (4) seed production technology of DuPont-Pioneer that makes use of transgenes in production of male-sterile lines, but gives hybrid seed with no transgenes. This review also includes a brief account of studies for discovery of heterotic QTL, genomic prediction of hybrid vigour and the development of heterotic groups/patterns and their importance in hybrid wheat production. The problem of high cost of hybrid seed due to required high seed rate in wheat relative to hybrid rice has also been addressed. The review concludes with a brief account of the current efforts and future possibilities in making hybrid wheat a commercial success.

Genetic improvement of grain protein content and other health-related constituents of wheat grain

Abstract: It is known that nearly one-third of the world population currently suffers from malnutrition due to lack of availability of adequate quantity of protein, vitamins and a number of micronutrients including Fe and Zn in their diet. A lack of other desirable bioactive compounds and dietary fibres (DF) in the diet also causes a variety of diseases. In some regions of the world, occurrence of Cd and As in wheat grain in excess of tolerance limits also adversely affects human health. In this short review, we summarize the current status of knowledge about the genetic control of the accumulation of a variety of nutritional constituents in wheat grain and then describe examples where noticeable improvements have been made using breeding approaches. We also describe the gaps that need to be bridged for better understanding of the genetic architecture of these important traits. The development and use of molecular markers in marker-assisted selection (MAS) for developing wheat varieties with improved grain quality has also been discussed.

Therapeutic genome editing: prospects and challenges

Abstract: Recent advances in the development of genome editing technologies based on programmable nucleases have substantially improved our ability to make precise changes in the genomes of eukaryotic cells. Genome editing is already broadening our ability to elucidate the contribution of genetics to disease by facilitating the creation of more accurate cellular and animal models of pathological processes. A particularly tantalizing application of programmable nucleases is the potential to directly correct genetic mutations in affected tissues and cells to treat diseases that are refractory to traditional therapies. Here we discuss current progress toward developing programmable nuclease–based therapies as well as future prospects and challenges.

Genetic Data Analysis II. Methods for Discrete Population Genentic Data

Abstract: ‘‘Gentlemen don’t need mistletoe’’ said the Christmas whiskey billboard I saw recently in Florida, a garish reminder of how much mistletoe lore is embedded in western society. Mistletoe The Genus Viscum, one in the series of medicinal and aromatic plants for industry and academic researchers, centers on the mistletoe in this advertisement, the common European mistletoe,Viscum album. There are helpful discussions on African, Asian, and Argentine mistletoes and their uses but the corpus of the book deals with V. album. Viscum album, considered sacred by the Druids, is no doubt the most widely used parasitic angiosperm for various health concoctions. As a result, much has been learned about its biochemistry and pharmaceutical potential. A great deal of the work on the culture and utilization ofV. album has been done by investigators at Institute Hiscia Center for Cancer Research in Switzerland where votaries of Rudolf Steiner’s distinct form of homeopathy have used mistletoe extracts (‘‘Iscador’’) for many years in cancer treatment. Mistletoe collected from less common hosts are considered to have greater efficacy in preparation of Iscador. As a result, there is a helpful chapter on culturing V. album which is not as difficult as might be imagined for an obligate parasite. Most of the chapters deal with the medicinal aspects of mistletoe including toxicology, clinical aspects, chemistry, and biochemistry emphasizing the lectins which are one of the more desirable compounds produced by the parasite. I found the treatment by Bu ̈ssing (Biological and pharmacological properties of Viscum album L.) helpful because it reviews the link between folk and modern medicine. However, several relevant papers were omitted which are included in a recent excellent review of mistletoes (Watson 2001). Like many books with a diversity of authors, the quality of chapters varies. Obviously produced as a reference volume, Mistletoe lacks an extensive index. Especially aggravating is the lack of an author’s index, limiting the value of the book for anyone looking for specific papers. These days, $70 for a hardbound monograph is reasonable. Color images are well-produced but some of the black and white figures are blurry in my copy. This volume will be of value to ethnobotanists, anyone interested in alternative medicines, and students of mistletoes and parasitic plants. LITERATURE CITED

Identification of a Functional Transposon Insertion in the Maize Domestication Gene tb1

Abstract: Genetic diversity created by transposable elements is an important source of functional variation upon which selection acts during evolution. Transposable elements are associated with adaptation to temperate climates in Drosophila, a SINE element is associated with the domestication of small dog breeds from the gray wolf and there is evidence that transposable elements were targets of selection during human evolution. Although the list of examples of transposable elements associated with host gene function continues to grow, proof that transposable elements are causative and not just correlated with functional variation is limited. Here we show that a transposable element (Hopscotch) inserted in a regulatory region of the maize domestication gene, teosinte branched1 (tb1), acts as an enhancer of gene expression and partially explains the increased apical dominance in maize compared to its progenitor, teosinte. Molecular dating indicates that the Hopscotch insertion predates maize domestication by at least 10,000 years, indicating that selection acted on standing variation rather than new mutation.

Chilling and Drought Stresses in Crop Plants: Implications, Cross Talk, and Potential Management Opportunities

Abstract: Plants face a combination of different abiotic stresses under field conditions which are lethal to plant growth and production. Simultaneous occurrence of chilling and drought stresses in plants due to the drastic and rapid global climate changes, can alter the morphological, physiological and molecular responses. Both these stresses adversely affect the plant growth and yields due to physical damages, physiological and biochemical disruptions, and molecular changes. In general, the co-occurrence of chilling and drought combination is even worse for crop production rather than an individual stress condition. Plants attain various common and different physiological and molecular protective approaches for tolerance under chilling and drought stresses. Nevertheless, plant responses to a combination of chilling and drought stresses are unique from those to individual stress. In the present review, we summarized the recent evidence on plant responses to chilling and drought stresses on shared as well as unique basis and tried to find a common thread potentially underlying these responses. We addressed the possible cross talk between plant responses to these stresses and discussed the potential management strategies for regulating the mechanisms of plant tolerance to drought and/or chilling stresses. To date, various novel approaches have been tested in minimizing the negative effects of combine stresses. Despite of the main improvements there is still a big room for improvement in combination of drought and chilling tolerance. Thus, future researches particularly using biotechnological and molecular approaches should be carried out to develop genetically engineered plants with enhanced tolerance against these stress factors.

A MicroRNA as a Translational Repressor of APETALA2 in Arabidopsis Flower Development

Abstract: Fig.4. Neutralization by donor and pooled subtype C plasma. (A) Neutralization profile of plasma-derived donor (green) and recipient (blue) Env pseudotypes from transmission pair 135 by donor plasma. Virus infectivity, as a percentage of the control, is plotted along the vertical axis. The reciprocal of the plasma dilution is graphed along the horizontal axis on a log 10 scale. Each curve represents the sensitivity to neutralization of an individual Env pseudotype. (B) The distribution of neutralization sensitivity for donor (green) and recipient (blue) Env pseudotypes for five transmission pairs, with IC 50 values for donor plasma (rounded to the nearest two-digit value) plotted on the horizontal axis. The fraction of Env pseudotypes with a given IC 50 is indicated on the vertical axis. (C) Linear regression analysis of neutralization by donor (horizontal axis) and pooled (vertical axis) plasma for donor (green) and recipient (blue) Env pseudotypes (R-squared value 0.23; P value 0.00002; slope 0.31, standard error 0.07). The number of Env pseudotypes evaluated was 106 (5 donor and 7 recipient), 109 (8 donor and 3 recipient), 135 (14 donor and 5 recipient), 55 (12donor and 8 recipient), and 53 (6 donor and 3 recipient). R EPORTS