Health-Promoting compounds in Potatoes: Tuber exhibiting great potential for human health.

Potatoes are consumed worldwide because of their high accessibility, low cost, taste, and diversity of cooking methods. The high carbohydrate content of potatoes masks the presence of -vitamins, polyphenols, minerals, amino acids, lectins and protein inhibitors in the minds of consumers. The consumption of potatoes faces challenges among health-conscious people. This review paper attempted to provide up-to-date information on new metabolites reported in potatoes that play role in disease prevention and overall human well-being. We tried to compile information on antidiabetic, antihypertensive, anticancer, antiobesity, antihyperlipidemic, and anti-inflammatory potential of potato along with role in improving gut health and satiety. In-vitro studies, human cell culture, and experimental animal and human clinical studies showed potatoes to exhibit a variety of health-enhancing properties. This article will not only popularize potato as a healthy food, but will also improve its use as a staple for the foreseeable future.

Mechanistic Concept of Physiological, Biochemical, and Molecular Responses of the Potato Crop to Heat and Drought Stress.

Most cultivated potatoes are tetraploid, and the tuber is the main economic part that is consumed due to its calorific and nutritional values. Recent trends in climate change led to the frequent occurrence of heat and drought stress in major potato-growing regions worldwide. The optimum temperature for tuber production is 15-20 °C. High-temperature and water-deficient conditions during the growing season result in several morphological, physiological, biochemical, and molecular alterations. The morphological changes under stress conditions may affect the process of stolon formation, tuberization, and bulking, ultimately affecting the tuber yield. This condition also affects the physiological responses, including an imbalance in the allocation of photoassimilates, respiration, water use efficiency, transpiration, carbon partitioning, and the source-sink relationship. The biochemical responses under stress conditions involve maintaining ionic homeostasis, synthesizing heat shock proteins, achieving osmolyte balance, and generating reactive oxygen species, ultimately affecting various biochemical pathways. Different networks that include both gene regulation and transcription factors are involved at the molecular level due to the combination of hot and water-deficient conditions. This article attempts to present an integrative content of physio-biochemical and molecular responses under the combined effects of heat and drought, prominent factors in climate change. Taking into account all of these aspects and responses, there is an immediate need for comprehensive screening of germplasm and the application of appropriate approaches and tactics to produce potato cultivars that perform well under drought and in heat-affected areas.

Coupled atmosphere-ice-ocean dynamics during Heinrich Stadial 2.

Our understanding of climate dynamics during millennial-scale events is incomplete, partially due to the lack of their precise phase analyses under various boundary conditions. Here we present nine speleothem oxygen-isotope records from mid-to-low-latitude monsoon regimes with sub-centennial age precision and multi-annual resolution, spanning the Heinrich Stadial 2 (HS2) - a millennial-scale event that occurred at the Last Glacial Maximum. Our data suggests that the Greenland and Antarctic ice-core chronologies require +320- and +400-year adjustments, respectively, supported by extant volcanic evidence and radiocarbon ages. Our chronological framework shows a synchronous HS2 onset globally. Our records precisely characterize a centennial-scale abrupt "tropical atmospheric seesaw" superimposed on the conventional "bipolar seesaw" at the beginning of HS2, implying a unique response/feedback from low-latitude hydroclimate. Together with our observation of an early South American monsoon shift at the HS2 termination, we suggest a more active role of low-latitude hydroclimate dynamics underlying millennial events than previously thought.

Impact of environment and LULC changes on groundwater resources in the Soan Basin, western Himalaya.

The present study assesses the environmental and Land Use Landcover (LULC) changes in the Soan Basin, western Himalaya between 1999 and 2015 and their impacts on groundwater quality and static water level (SWL). An increase in the area of agricultural land (19%), settlement (~ 300%), and dense forest (25%) at the expense of open forest and waste cum grazing land was observed subsequently since the year 1999. SWL was lowered in the basin between 1999 and 2013 due to less groundwater recharge with decreased permeable surfaces and decreased rainfall, except in a few locations in the valley fill region plausibly due to the secondary recharge through seepages, infiltration of irrigational wastewater, and waterlogging in the agricultural fields. A continuous lowering of SWL after 2015, even after increasing the rain amount significantly, indicates overexploitation of groundwater in the region. Enhanced use of fertilizers has resulted in an increased concentration of Na+ and Cl- ions in groundwater. The results are further substantiated by comparing the hydrochemical data for the years 1999 and 2015, which again indicate the high concentration of Na+ and Cl- ions due to waterlogging. From 1999 to 2015, nitrate (average 12.8 mg/l to 16 mg/l) and fluoride concentration (average 0.3 to 0.9) have also increased because of the excessive use of fertilizers in the agricultural fields. The increasing trend of nitrate concentrations in water in successive years since 1994 supports the changes observed in an agricultural pattern in LULC maps for the years 1999, 2009, and 2015. The results divulge that the groundwater quality of the basin has been deteriorating due to an increase in agricultural practices and demands for appropriate water management practices.

Functional Fermented Probiotics, Prebiotics, and Synbiotics from Non-Dairy Products: A Perspective from Nutraceutical.

The current trend of health-conscious consumers and healthy food habits prompts researchers to explore developing food products with synbiotic benefits. Synbiotic foods have gained popularity in recent years due to their functional, nutritional, physiological, and therapeutic characteristics. Lactose intolerance, dyslipidemia, and allergic milk proteins become the barriers in the development of dairy probiotics. The present scenario of an increase in the demand for vegetarian products leads to a rise in the consumption of non-dairy probiotics. Prebiotics like, resistant starch, inulin, and polyphenols are selectively used by gut microbiota to enhance the selection and colonization of probiotics bacteria. Probiotic's action mechanisms include the production of bacteriocins, peptides, short-chain fatty acids, amino acids, vitamins, and other metabolites. Therefore, this review article explores the alternative sources of probiotics so it will help to an understanding of non-dairy based functional fermented foods for both pro and prebiotics. Dietary fibers in vegetables, fruits, and cereals are one of prospective prebiotics and highlighted the various methods for making non-dairy synbiotics based on dietary fibers, such as microencapsulation, freeze-drying, and spray drying is also addressed.

Anthocyanin-Rich Vegetables for Human Consumption-Focus on Potato, Sweetpotato and Tomato.

Malnutrition, unhealthy diets, and lifestyle changes have become major risk factors for non-communicable diseases while adversely impacting economic growth and sustainable development. Anthocyanins, a group of flavonoids that are rich in fruits and vegetables, contribute positively to human health. This review focuses on genetic variation harnessed through crossbreeding and biotechnology-led approaches for developing anthocyanins-rich fruit and vegetable crops. Significant progress has been made in identifying genes involved in anthocyanin biosynthesis in various crops. Thus, the use of genetics has led to the development and release of anthocyanin-rich potato and sweet potato cultivars in Europe and the USA. The purple potato 'Kufri Neelkanth' has been released for cultivation in northern India. In Europe, the anthocyanin-rich tomato cultivar 'Sun Black' developed via the introgression of Aft and atv genes has been released. The development of anthocyanin-rich food crops without any significant yield penalty has been due to the use of genetic engineering involving specific transcription factors or gene editing. Anthocyanin-rich food ingredients have the potential of being more nutritious than those devoid of anthocyanins. The inclusion of anthocyanins as a target characteristic in breeding programs can ensure the development of cultivars to meet the nutritional needs for human consumption in the developing world.

A sustainable approach of turning potato waste towards bioethanol production using indigenous microbes of Himachal Pradesh, India.

Potato peel waste is one of the zero-value wastes with the potential of bioethanol production through the Waste to Energy (WtE) approach. The newly isolated, phenotypically characterized, and molecular identified high-altitude strain, B. amyloliquefaciens, shown promising starch hydrolysis (12.06 g/L reducing sugars) over acid hydrolysis and is capable of working at 30-50 °C and pH 6.0-8.0. The ethanol production by Acinetobacter sp. (a newly isolated, phenotypically characterized, molecular identified) has been modelled and optimized through the central composite design of response surface methodology by taking the fermentation variables as input variables and ethanol yield as the output variable. The ethanol production by Acinetobacter sp. showcased a non-linear relationship of fermentation variables with the ethanol yield (5.83 g/L) with a 99.11% desirability function (R2) and 97.50 adj. R2 values. Optimal fermentation variables of 38.8% substrate concentration, 7% inoculum, pH 5.45 have been utilized for bioethanol production in 55.27 h at 27 °C. Overall, the present study evaluated the efficiency of newly isolated, indigenous extremophilic microbes of The Himalayan region in sustainable bioethanol production from zero-value waste "Potato peel waste" through the WtE approach. Moreover, the present study introduces the promising, unexplored extremophilic microbial strains with the starch-hydrolyzing and fermentation capabilities to bioethanol biorefinery.

Towards optimizing peptide-based inhibitors of protein-protein interactions: predictive saturation variation scanning (PreSaVS).

A simple-to-implement and experimentally validated computational workflow for sequence modification of peptide inhibitors of protein-protein interactions (PPIs) is described.

Effect of potato apical leaf curl disease on glycemic index and resistant starch of potato (Solanum tuberosum L.) tubers.

Tomato leaf curl New Delhi virus-potato (ToLCNDV-potato) causes potato apical leaf curl disease which severely affects nutritional parameters such as carbohydrate, protein, and starch biosynthesis thereby altering glycemic index (GI) and resistant starch (RS) of potato. ToLCNDV-potato virus was inoculated on potato cultivars (Kufri Pukhraj [susceptible]; Kufri Bahar [resistant]) and various quality parameters of potato tuber were studied. There was a significant (P < 0.01) reduction in starch, amylose and resistant starch contents in the infected tubers. However, carbohydrate and amylopectin increased significantly (P < 0.01) which contributes to increased starch digestibility reflected with high GI and glycemic load values. Besides, ToLCNDV-potato infection leads to a significant increase in reducing sugar, sucrose, amino acid and protein in potato tubers. This is a first-ever study that highlights the impact of biotic stress on GI, RS and nutritional quality parameters of potato which is a matter of concern for consumers.

Predicting and Experimentally Validating Hot-Spot Residues at Protein-Protein Interfaces.

Protein-protein interactions (PPIs) are vital to all biological processes. These interactions are often dynamic, sometimes transient, typically occur over large topographically shallow protein surfaces, and can exhibit a broad range of affinities. Considerable progress has been made in determining PPI structures. However, given the above properties, understanding the key determinants of their thermodynamic stability remains a challenge in chemical biology. An improved ability to identify and engineer PPIs would advance understanding of biological mechanisms and mutant phenotypes and also provide a firmer foundation for inhibitor design. In silico prediction of PPI hot-spot amino acids using computational alanine scanning (CAS) offers a rapid approach for predicting key residues that drive protein-protein association. This can be applied to all known PPI structures; however there is a trade-off between throughput and accuracy. Here we describe a comparative analysis of multiple CAS methods, which highlights effective approaches to improve the accuracy of predicting hot-spot residues. Alongside this, we introduce a new method, BUDE Alanine Scanning, which can be applied to single structures from crystallography and to structural ensembles from NMR or molecular dynamics data. The comparative analyses facilitate accurate prediction of hot-spots that we validate experimentally with three diverse targets: NOXA-B/MCL-1 (an α-helix-mediated PPI), SIMS/SUMO, and GKAP/SHANK-PDZ (both ß-strand-mediated interactions). Finally, the approach is applied to the accurate prediction of hot-spot residues at a topographically novel Affimer/BCL-xL protein-protein interface.

Key players associated with tuberization in potato: potential candidates for genetic engineering.

Tuberization in potato (Solanum tuberosum L.) is a complex biological phenomenon which is affected by several environmental cues, genetic factors and plant nutrition. Understanding the regulation of tuber induction is essential to devise strategies to improve tuber yield and quality. It is well established that short-day photoperiods promote tuberization, whereas long days and high-temperatures inhibit or delay tuberization. Worldwide research on this complex biological process has yielded information on the important bio-molecules (proteins, RNAs, plant growth regulators) associated with the tuberization process in potato. Key proteins involved in the regulation of tuberization include StSP6A, POTH1, StBEL5, StPHYB, StCONSTANS, Sucrose transporter StSUT4, StSP5G, etc. Biomolecules that become transported from "source to sink" have also been suggested to be important signaling candidates regulating the tuberization process in potatos. Four molecules, namely StSP6A protein, StBEL5 RNA, miR172 and GAs, have been found to be the main candidates acting as mobile signals for tuberization. These biomolecules can be manipulated (overexpressed/inhibited) for improving the tuberization in commercial varieties/cultivars of potato. In this review, information about the genes/proteins and their mechanism of action associated with the tuberization process is discussed.

Allosterically Regulated Phosphatase Activity from Peptide-PNA Conjugates Folded Through Hybridization.

The importance of spatial organization in short peptide catalysts is well recognized. We synthesized and screened a library of peptides flanked by peptide nucleic acids (PNAs) such that the peptide would be constrained in a hairpin loop upon hybridization. A screen for phosphatase activity led to the discovery of a catalyst with >25-fold rate acceleration over the linear peptide. We demonstrated that the hybridization-enforced folding of the peptide is necessary for activity, and designed a catalyst that is allosterically controlled using a complementary PNA sequence.

Protein Camouflage: Supramolecular Anion Recognition by Ubiquitin.

Progress in the field of bio-supramolecular chemistry, the bottom-up assembly of protein-ligand systems, relies on a detailed knowledge of molecular recognition. To address this issue, we have characterised complex formation between human ubiquitin (HUb) and four supramolecular anions. The ligands were: pyrenetetrasulfonic acid (4PSA), p-sulfonato-calix[4]arene (SCLX4), bisphosphate tweezers (CLR01) and meso-tetrakis (4-sulfonatophenyl)porphyrin (TPPS), which vary in net charge, size, shape and hydrophobicity. All four ligands induced significant changes in the HSQC spectrum of HUb. Chemical shift perturbations and line-broadening effects were used to identify binding sites and to quantify affinities. Supporting data were obtained from docking simulations. It was found that these weakly interacting ligands bind to extensive surface patches on HUb. A comparison of the data suggests some general indicators for the protein-binding specificity of supramolecular anions. Differences in binding were observed between the cavity-containing and planar ligands. The former had a preference for the arginine-rich, flexible C terminus of HUb.

Flavouring compounds in Indian potato snacks.

Market for processed potato products is rising day by day. Flavour plays important role in decision making by consumers due to their preferences for better tasting food. In potato and potato products, glutamic acid, aspartic acid, guanosine 5'-monophosphate (GMP) and adenosine 5'-monophosphate (AMP) are the major umami compounds which contribute towards flavour. Therefore, umami 5' nucleotides (AMP+GMP) were estimated from local potato products available as common fried products in the Indian markets and processed potato products being sold by the retailers. The analysis was also carried in raw, microwaved and pressure cooked tubers of forty seven Indian potato cultivars. Umami 5' nucleotide content ranged from 2.63 (Aloo seekh) to 8.26 µg/g FW (fried lachcha) in local potato products. In processed potato products, the content ranged from 2.72 µg/g FW (Smiles) to 14.75 µg/g FW (Aloo Bhujia). Along with aloo bhujia, umami 5' nucleotides were also high in dehydrated aloo lachcha (11.14 µg/g FW) and dehydrated potato chips (10.13 µg/g FW) and low in Smiles (2.72 µg/g FW) and Potato Shortz (3.40 µg/g FW). The study suggests that the potato products prepared solely from potato contained higher levels of umami 5' nucleotides compared to other products prepared by mixing potato with other cereals and vegetables. In Indian potato cultivars overall there was 14 % increase on microwave cooking and 31 % increase in flavouring compounds on pressure cooking. This type of study enabled in identifying better tasting cultivars for further product development and also to develop products with less addition of salt.

Cloning and expression of low temperature active endoglucanase EG5C from Paenibacillus sp. IHB B 3084.

The endoglucanase gene designated as EG5C encoding cold active endoglucanase produced by Paenibacillus sp. IHB B 3084 was cloned and expressed in Escherichia coli BL21(DE3). The gene consisting of 1719bp open reading frame encoded a protein of 573 amino acids with a predicted molecular weight of 63.5kDa. The presence of N-terminal catalytic domain of the glycosyl hydrolase family 5 (GH5) and C-terminal carbohydrate binding X2 domain suggested the modular nature of the enzyme. The native signal peptide of EG5C was capable of efficiently secreting the enzyme with near equal activities in the cytoplasmic and extracellular fractions. The recombinant enzyme purified 9.46 fold to homogeneity with 22.33% yield gave 7.758IU/mg specific activity. The enzyme was stable over the broad pH range of 4-12 with more than 50% residual activity. The optimal activity was at 40°C with 70% relative activity at 5°C. The low temperature activity despite the shorter linker region suggested a novel cold adaptation mechanism by the enzyme. The enzyme displayed higher activity on carboxymethylcellulose than avicel which is useful in maintaining the tensile strength of fiber. The efficient secretion and low temperature activity offer prospect for large-scale production and industrial application of the endoglucanase.

Molecular tweezers inhibit islet amyloid polypeptide assembly and toxicity by a new mechanism.

In type-2 diabetes (T2D), islet amyloid polypeptide (IAPP) self-associates into toxic assemblies causing islet ß-cell death. Therefore, preventing IAPP toxicity is a promising therapeutic strategy for T2D. The molecular tweezer CLR01 is a supramolecular tool for selective complexation of K residues in (poly)peptides. Surprisingly, it inhibits IAPP aggregation at substoichiometric concentrations even though IAPP has only one K residue at position 1, whereas efficient inhibition of IAPP toxicity requires excess CLR01. The basis for this peculiar behavior is not clear. Here, a combination of biochemical, biophysical, spectroscopic, and computational methods reveals a detailed mechanistic picture of the unique dual inhibition mechanism for CLR01. At low concentrations, CLR01 binds to K1, presumably nucleating nonamyloidogenic, yet toxic, structures, whereas excess CLR01 binds also to R11, leading to nontoxic structures. Encouragingly, the CLR01 concentrations needed for inhibition of IAPP toxicity are safe in vivo, supporting its development toward disease-modifying therapy for T2D.

Differential proteomics of Picrorhiza kurrooa Royle ex Benth. in response to dark stress.

Picrorhiza (Picrorhiza kurrooa Royle ex Benth.) an important medicinal herb of western Himalayan region has been used to treat various diseases and disorders. Over-harvesting and lack of cultivation has led to its entry in Red Data Book as an endangered species. Further, its very restrictive habitat and lesser biomass production are major limitations for bringing it under commercial cultivation. All these issues necessitate deeper insights into mechanisms governing its growth and interaction with the environmental cues. Light may be one of the important factors to be studied for its role in regulating growth and adaptation of Picrorhiza as in natural habitat it prefers shady niches. Keeping this in view, proteome of Picrorhiza kept under light vis-à-vis under dark was analysed and compared. Leaf as well as root proteome of Picrorhiza was studied. Denaturing two dimensional gel electrophoresis and mass spectrometry techniques were used to detect and identify differentially expressed proteins, respectively. Twenty two proteins from leaf and 25 proteins from root showed differential expression levels under dark and light conditions. Among the differentially expressed proteins, majority were those involved in metabolism, protein synthesis, and stress and defense response. Other differentially expressed proteins were those involved in photosynthetic process, photorespiration and few proteins were with unknown function indicating that many different processes work together to establish a new cellular homeostasis in response to dark and light conditions. Proteins found to be differentially expressed under light vis-à-vis dark conditions suggested a range of biochemical pathways and processes being associated with response of plant to dark conditions. The identified proteins may be utilized for developing strategies for improving the biomass production/performance of Picrorhiza under varied light/dark habitats.

Cloning, characterization, expression analysis and inhibition studies of a novel gene encoding Bowman-Birk type protease inhibitor from rice bean.

This paper presents the first study describing the isolation, cloning and characterization of a full length gene encoding Bowman-Birk protease inhibitor (RbTI) from rice bean (Vigna umbellata). A full-length protease inhibitor gene with complete open reading frame of 327 bp encoding 109 amino acids was cloned from rice bean seeds using degenerate primer set. BlastP search revealed that the RbTI encoded amino acid of approx 13.0 kDa and shared 99% homology each with BBI from Phaseolus parvulus, Vigna trilobata and Vigna vexilata. Phylogenetic tree also showed close relationship of RbTI with BBI from other members of Leguminaceae family. RbTI gene was further confirmed as intronless (GenBank accession no. KJ159908). The secondary and 3D-structural models for the RbTI were predicted with homology modeling. qRT-PCR studies revealed the highest RbTI expression in the seeds nearing maturity, whereas the low expression of the gene was noticed in young leaves. The isolated RbTI was successfully expressed in Escherichiacoli and the highest expression was recorded after 5.5h of induction. Study on the inhibitory activity of expressed protein against the gut proteases of Hessian fly larvae revealed 87% inhibition. The novel RbTI gene will further broaden the pool of plant defense genes and could be an ideal choice for developing transgenic crops resistant to insect pests with high economic value. In addition, it has the potential to be used as a probe for selection of insect- and pathogen-resistant genotypes.

Translation initiation factor 5A in Picrorhiza is up-regulated during leaf senescence and in response to abscisic acid.

Translation initiation, the first step of protein synthesis process is the principal regulatory step controlling translation and involves a pool of translation initiation factors. In plants, from recent studies it is becoming evident that these translation initiation factors impact various aspects of plant growth and development in addition to their role in protein synthesis. Eukaryotic translation initiation factor eIF5A is one such factor which functions in start site selection for the eIF2-GTP-tRNAi ternary complex within the ribosomal-bound preinitiation complex and also stabilizes the binding of GDP to eIF2. In the present study we have cloned and analysed a gene (eIF5a) encoding eIF5A from Picrorhiza (Picrorhiza kurrooa Royle ex Benth.) a medicinal plant of the western Himalayan region. The full length eIF5a cDNA consisted of 838 bp with an open reading frame of 480 bp, 88 bp 5' untranslated region and 270 bp 3' untranslated region. The deduced eIF5A protein contained 159 amino acids with a molecular weight of 17.359 kDa and an isoelectric point of 5.59. Secondary structure analysis revealed eIF5A having 24.53% α-helices, 8.81% ß-turns, 23.27% extended strands and 43.40% random coils. pk-eIF5a transcript was found to be expressing during the active growth phase as well as during leaf senescence stage, however, highest expression was observed during leaf senescence stage. Further, its expression was up-regulated in response to exogenous application of abscisic acid. Both high intensity as well as low intensity light decreased the expression of pk-eIF5a. The findings suggest eIF5a to be an important candidate to develop genetic engineering based strategies for delaying leaf senescence.

Components of antioxidant system of Picrorhiza kurrooa exhibit different spatio-temporal behavior.

Antioxidant system is one of the important factors in regulating plant growth, development and adaptation. Thus, in order to have better insights into molecular mechanisms of growth and adaptation of a plant it is prerequisite to have known the status of various components of the antioxidant system of the plant. Here we studied the status of enzymatic and non-enzymatic components of the antioxidant system of picrorhiza (Picrorhiza kurrooa). Picrorhiza is an important medicinal herb of western Himalayan region and has been listed in the Red Data Book as an endangered species. Spatio-temporal analysis of ascorbic acid and glutathione in leaf, root and rhizome during different stages of development revealed differential status of these antioxidant molecules. Of the three tissues, ascorbic acid was found to be highest in leaves and lowest in roots. Interestingly, just opposite to that, glutathione was highest in roots and lowest in leaves. Using degenerate primers based approach followed by rapid amplification of complementary DNA (cDNA) ends method, full length cDNAs of three important genes namely Picrorhiza kurrooa ascorbate peroxidase (pkapx), Picrorhiza kurrooa monodehydroascorbate reductase (pkmdhar) and Picrorhiza kurrooa glutathione reductase (pkgr) of antioxidant system were cloned from picrorhiza. Complementary DNAs of pkapx, pkmdhar and pkgr contained 1,049, 2,016 and 1,664 bp, respectively. Expression analysis showed differential spatio-temporal expression of these genes. Expressions of all the three genes were found higher in roots as compared to rhizome and leaves. Temporal expression analysis of pkapx, pkmdhar and pkgr revealed differential transcript levels. Expression of pkapx exhibited negative correlation with the light intensity. Just opposite to the pkapx, expression pattern of pkgr revealed its positive correlation with light intensity. Expression pattern of pkmdhar revealed its light independent expression behavior. The findings may be useful to assess the role of cloned genes in picrorhiza growth, adaptation and can further be utilized for transgenic development for desired trait(s).