Wheat production and productivity in the past witnessed a remarkable growth. However, this growth rate could not be sustained during the last decade, causing concern among world wheat community. ...Marker-assisted selection (MAS), which is being practiced for improvement of a variety of traits in wheat around the world, may at least partly help in providing the desired solution. Marker-trait associations are now known for a number of simple, but difficult-to-score traits, so that MAS has been found useful for improvement of several of these important economic traits. Breeding strategies including marker-assisted backcrossing, forward breeding, MAS involving doubled haploid technology and F₂ enrichment have been successfully utilized for this purpose. However, for improvement of complex polygenic traits, newer technologies based on high throughput genotyping associated with new marker systems (e.g., DArT and SNP), and new selection strategies such as AB-QTL, mapping-as-you-go, marker-assisted recurrent selection and genome-wide selection will have to be tried in future. The progress made in all these aspects of marker-assisted wheat breeding, and the limitations and future prospects of this emerging technology have been reviewed in this article.
Cultivated groundnut or peanut (
Arachis hypogaea
L.), an allotetraploid (2
n
= 4
x
= 40), is a self pollinated and widely grown crop in the semi-arid regions of the world. Improvement of drought ...tolerance is an important area of research for groundnut breeding programmes. Therefore, for the identification of candidate QTLs for drought tolerance, a comprehensive and refined genetic map containing 191 SSR loci based on a single mapping population (TAG 24 × ICGV 86031), segregating for drought and surrogate traits was developed. Genotyping data and phenotyping data collected for more than ten drought related traits in 2–3 seasons were analyzed in detail for identification of main effect QTLs (M-QTLs) and epistatic QTLs (E-QTLs) using QTL Cartographer, QTLNetwork and Genotype Matrix Mapping (GMM) programmes. A total of 105 M-QTLs with 3.48–33.36% phenotypic variation explained (PVE) were identified using QTL Cartographer, while only 65 M-QTLs with 1.3–15.01% PVE were identified using QTLNetwork. A total of 53 M-QTLs were such which were identified using both programmes. On the other hand, GMM identified 186 (8.54–44.72% PVE) and 63 (7.11–21.13% PVE), three and two loci interactions, whereas only 8 E-QTL interactions with 1.7–8.34% PVE were identified through QTLNetwork. Interestingly a number of co-localized QTLs controlling 2–9 traits were also identified. The identification of few major, many minor M-QTLs and QTL × QTL interactions during the present study confirmed the complex and quantitative nature of drought tolerance in groundnut. This study suggests deployment of modern approaches like marker-assisted recurrent selection or genomic selection instead of marker-assisted backcrossing approach for breeding for drought tolerance in groundnut.
The last two decades have witnessed a remarkable activity in the development and use of molecular markers both in animal and plant systems. This activity started with low-throughput restriction ...fragment length polymorphisms and culminated in recent years with single nucleotide polymorphisms (SNPs), which are abundant and uniformly distributed. Although the latter became the markers of choice for many, their discovery needed previous sequence information. However, with the availability of microarrays, SNP platforms have been developed, which allow genotyping of thousands of markers in parallel. Besides SNPs, some other novel marker systems, including single feature polymorphisms, diversity array technology and restriction site-associated DNA markers, have also been developed, where array-based assays have been utilized to provide for the desired ultra-high throughput and low cost. These microarray-based markers are the markers of choice for the future and are already being used for construction of high-density maps, quantitative trait loci (QTL) mapping (including expression QTLs) and genetic diversity analysis with a limited expense in terms of time and money. In this study, we briefly describe the characteristics of these array-based marker systems and review the work that has already been done involving development and use of these markers, not only in simple eukaryotes like yeast, but also in a variety of seed plants with simple or complex genomes.
Olive (Olea europaea Linn., Fam. Oleaceae) is commonly known as Zaytoon in Mediterranean region. Its fruits and oil are essential components of Mediterranean diets. Olive tree is a prevalent plant ...species and one of the important cultivated crops of Mediterranean region. Oleuropein is a phenolic constituents of olive, which, along with its related compounds, has been indicated to be majorly responsible for its beneficial effects. Oleuropein is a secoiridoid type of phenolic compound and consists of three structural subunits: hydroxytyrosol, elenolic acid, and a glucose molecule. It is also reported to be the chemotaxonomic marker of olive. The oleuropein is reported to possess a number of biological activities including action against dyslipidemia, antiobesity, antidiabetic, antioxidant, antiatherogenic, antihypertensive, antiinflammatory, and hepatoprotective actions. The scientific evidence supports the role of oleuropein as a potential agent against metabolic syndrome. The present review discusses chemistry of oleuropein along with potential role of oleuropein with reference to pathophysiology of metabolic syndrome.
The current scientific community is facing a daunting challenge to unravel reliable natural compounds with realistic potential to treat neurological disorders such as Alzheimer's disease (AD). The ...reported compounds/drugs mostly synthetic deemed the reliability and therapeutic potential largely due to their complexity and off-target issues. The natural products from nutraceutical compounds emerge as viable preventive therapeutics to fill the huge gap in treating neurological disorders. Considering that Alzheimer's disease is a multifactorial disease, natural compounds offer the advantage of a multitarget approach, tagging different molecular sites in the human brain, as compared with the single-target activity of most of the drugs so far used to treat Alzheimer's disease. A wide range of plant extracts and phytochemicals reported to possess the therapeutic potential to Alzheimer's disease includes curcumin, resveratrol, epigallocatechin-3-gallate, morin, delphinidins, quercetin, luteolin, oleocanthal, and other phytochemicals such as huperzine A, limonoids, and azaphilones. Reported targets of these natural compounds include inhibition of acetylcholinesterase, amyloid senile plaques, oxidation products, inflammatory pathways, specific brain receptors, etc. We tenaciously aimed to review the in-depth potential of natural products and their therapeutic applications against Alzheimer's disease, with a special focus on a diversity of medicinal plants and phytocompounds and their mechanism of action against Alzheimer's disease pathologies. We strongly believe that the medicinal plants and phytoconstituents alone or in combination with other compounds would be effective treatments against Alzheimer's disease with lesser side effects as compared to currently available treatments.
Common wheat is unique in providing a large number of diverse end-products, including chapati, biscuits, bread and noodles. Grain weight and other grain traits contribute to grain yield and milling ...quality. Many earlier QTL studies reported at least 332 QTLs for grain traits including grain weight. We conducted a QTL analysis (composite interval mapping) of grain traits using a set of 92 recombinant inbred lines (RILs) derived from a cross between Rye Selection 111 (superior grain traits) and Chinese Spring (inferior grain traits). Forty-five QTLs for six grain traits, on 19 of the 21 chromosomes (except 2D and 3D) were identified. Nineteen of these QTLs, each for 2–3 traits were located on six chromosomes (2A, 3B, 6B, 6D, 7A and 7D). The pleiotropic nature or tight linkage of QTLs controlling different correlated traits (except the one on 6DS) was confirmed by joint MCIM. Meta-QTL (M-QTL) analysis of grain traits (including grain weight) was conducted using earlier reported QTL results (including QTLs reported in the present study). From this analysis, 23 M-QTLs were identified on eight chromosomes. These results were compared with those of our current QTL analysis and previous studies; three M-QTLs were identified as relatively more important for molecular breeding and will facilitate further work on genetic architecture and cloning of QTLs for grain traits including grain weight.
The involvement of melatonin in the regulation of salt stress acclimation has been shown in plants in this present work. We found that the GOAL cultivar of wheat (Triticum aestivum L.) was the most ...salt‐tolerant among the investigated cultivars, GOAL, HD‐2967, PBW‐17, PBW‐343, PBW‐550, and WH‐1105 when screened for tolerance to 100 mM NaCl. The application of 100 μM melatonin maximally reduced oxidative stress and improved photosynthesis in the cv. GOAL. Melatonin supplementation reduced salt stress‐induced oxidative stress by upregulating the activity of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR), and reduced the glutathione (GSH) production. This resulted in increased membrane stability, photosynthetic‐N use efficiency and photosynthesis in plants. The application of 50 μM of the ethylene biosynthesis inhibitor aminoethoxyvinylglycine (AVG) in the presence of melatonin and salt stress increased H2O2 content but reduced GR activity and GSH, photosynthesis, and plant dry mass. This signifies that melatonin‐mediated salt stress tolerance was related to ethylene synthesis as it improved antioxidant activity and photosynthesis of plants under salt stress. Thus, the interaction of melatonin and ethylene bears a prominent role in salt stress tolerance in wheat and can be used to develop salt tolerance in other crops.
The chromatin organizer SATB1 has been implicated in the development and progression of multiple cancers including breast and colorectal cancers. However, the regulation and role of SATB1 in ...colorectal cancers is poorly understood. Here, we demonstrate that expression of SATB1 is induced upon hyperactivation of Wnt/β-catenin signaling and repressed upon depletion of TCF7L2 (TCF4) and β-catenin. Using several colorectal cancer cell line models and the APC min mutant zebrafish in vivo model, we established that SATB1 is a novel target of Wnt/β-catenin signaling. We show that direct binding of TCF7L2/β-catenin complex on Satb1 promoter is required for the regulation of SATB1. Moreover, SATB1 is sufficient to regulate the expression of β-catenin, members of TCF family, multiple downstream effectors and mediators of Wnt pathway. SATB1 potentiates the cellular changes and expression of key cancer-associated genes in non-aggressive colorectal cells, promotes their aggressive phenotype and tumorigenesis in vivo. Conversely, depletion of SATB1 from aggressive cells reprograms the expression of cancer-associated genes, reverses their cancer phenotype and reduces the potential of these cells to develop tumors in vivo. We also show that SATB1 and β-catenin bind to the promoters of TCF7L2 and the downstream targets of Wnt signaling and regulate their expression. Our findings suggest that SATB1 shares a feedback regulatory network with TCF7L2/β-catenin signaling and is required for Wnt signaling-dependent regulation of β-catenin. Collectively, these results provide unequivocal evidence to establish that SATB1 reprograms the expression of tumor growth- and metastasis-associated genes to promote tumorigenesis and functionally overlaps with Wnt signaling critical for colorectal cancer tumorigenesis.
Environmental enrichment is a widely used experimental manipulation that physically, cognitively and socially stimulates individuals. It has a great variety of long‐term effects at neuroanatomical, ...neurochemical, and behavioral level; however, the influence of parental environmental enrichment during gestation and pregestation on the development of the offspring and on the mother's behavior has been poorly explored. This article presents a review of the literature from the year 2000 about the effects of maternal and paternal environmental enrichment on the behavioral, endocrine, and neural systems of offspring and parents. Relevant research terms were searched for on the biomedical databases, PubMed, Medline, ScienceDirect, and Google Scholar. The data suggest that paternal/maternal environmental enrichment can profoundly affect the developmental trajectories of offspring through putative epigenetic mechanisms. Environmental enrichment presents as a promising therapeutic tool for human health interventions, especially to counteract the deleterious effects of impoverished and adverse growing conditions.
The parental environmental enrichment paradigm demonstrates beneficial outcomes for the physiological, behavioral, and neural aspects of both parents and their non‐exposed offspring. This comprehensive review aims to consolidate the existing literature on the impact of maternal and paternal environmental enrichment on the behavioral, endocrine, and neural systems of both offspring and parents.
Melatonin (MT) and methyl jasmonate (MeJA) play important roles in the adaptation of plants to different stress factors by modulating stress tolerance mechanisms. The present study reports the ...involvement of MT (100 µM) in MeJA (10 µM)-induced photosynthetic performance and heat stress acclimation through regulation of the antioxidant metabolism and ethylene production in wheat (Triticum aestivum L.) plants. Plants exposed to 40 °C for 6 h per day for 15 days and allowed to retrieve at 28 °C showed enhanced oxidative stress and antioxidant metabolism, increased 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) activity and ethylene production, and decreased photosynthetic performance. In contrast, the exogenously applied MT and MeJA reduced oxidative stress through improved S-assimilation (+ 73.6% S content), antioxidant defense system (+ 70.9% SOD, + 115.8% APX and + 104.2% GR, and + 49.5% GSH), optimized ethylene level to 58.4% resulting in improved photosynthesis by 75%. The use of p-chlorophenyl alanine, a MT biosynthesis inhibitor along with MeJA in the presence of heat stress reduced the photosynthetic performance, ATP-S activity and GSH content, substantiated the requirement of MT in the MeJA-induced photosynthetic response of plants under heat stress. These findings suggest that MeJA evoked the plant's ability to withstand heat stress by regulating the S-assimilation, antioxidant defense system, and ethylene production, and improving photosynthetic performance was dependent on MT.
PDF
