Plants Engineered To Produce Insect Perfume Could Act As Pesticides Gizmodo Second, putting these transgenic plants in the field would attract pests away from crops." Their idea is to use the engineered organisms as part of advanced insect control...
Crude extracts from the whole plant of five different varieties (white, purple red, orange, pink and red) of Portulaca grandiflorawere screened for their in vitro antioxidant and total phenolic content. These plants were extracted by methanol, acetone and ethanol, respectively. Their total phenolic content as determined by Folin-Ciocalteu reagent, were ranging from 46.39-82.19 mg GAE/100 g, 36.72-56.45 mg GAE/100 g, and 41.46-85.70 mg GAE/100 g for methanolic, acetone and ethanolic extract, respectively. The antioxidant activity of plant extracts as determined by DPPH scavenging assay were ranging from 0.69-2.14 mg/mL, 1.40-4.38 mg gallic acid/g, and 7.32-29.21 mg ascorbic acid/g when expressed as IC50, GEAC and AEAC, respectively. The highest antioxidant activity was observed in acetone extract of orange variety (PG 3). Therefore, each part of the PG 3, i.e. leaf, stem and flower was separated and further evaluated. The results showed that the leaf of PG 3 contained the highest phenolic content and antioxidant activity. The present study suggests that extracts from P. grandiflora could be utilised as natural sources for antioxidant.
Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees – a readily available, inexpensive, biodegradable, and disposable material – can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings.
The two-component signaling system (TCS) - the major signaling pathway of bacteria – is found among higher eukaryotes only in plants where it regulates diverse processes such as the signaling of the phytohormone cytokinin. Cytokinin is perceived by a hybrid-histidine kinase receptor and the signal is transduced by a multi-step phospho-relay system of histidine phosphotransfer proteins (HPT) and different classes of response regulators (RR). To shed light on the origin and evolution of TCS members in plants, we conducted a comprehensive domain-based phylogenetic study across the relevant kingdoms including charophyceae algae, the group of green algae giving rise to land plants. Surprisingly, we identified a novel subfamily of cytokinin receptors with members only from the early diverging land plants Marchantia polymorpha and Physcomitrella patens and then experimentally characterized two members of this subfamily. HTPs of charophyceae seemed to be more closely related to those of land plants than to other groups of green algae. Further down the signaling pathway, the type-B RRs were found across all plant clades, but many members lack either the canonical Asp residue or the DNA-binding domain. In contrast, the type-A RRs seemed to be limited to land plants. Finally, the analysis provided hints that one additional group of RRs, the type-C RRs, might be degenerated receptors and thus evolutionary of a different origin than bona fide response regulators.
“Thousands of Indian farmers are committing suicide after growing GM crops.” It is no minor claim. Genetically modified crops revolutionise agriculture – but are controversial. They will feed the world, reduce the need for pesticides and fertilisers, and add health-protecting nutrients to those who consume them, say some. They are an ecological disaster in the making, say others, and impoverish the Third World farmers who grow them. Often quoted is the example of suicides among Indian farmers who grow GM crops. Ian Plewisexamines the data and the conclusion.
"Here, we review recent progress in computational modelling as applied to plant photosynthesis, with attention to the requirements for CAM, and recent advances in synthetic biology tool development. Lastly, we discuss possible options for multigene pathway construction in plants with an emphasis on CAM-into-C3 engineering. "
The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance.
Protein prenylation is required for a variety of growth and developmental processes in flowering plants. Here we report the consequences of loss of function of all known prenylation subunits in the moss Physcomitrella patens. As in Arabidopsis, protein farnesyltransferase and protein genanylgeranyltransferase type I are not required for viability. However, protein geranylgeranyltransferase type I activity is required for cell adhesion, polar cell elongation, and cell differentiation. Loss of protein geranylgeranyltransferase activity results in colonies of round, single-celled organisms that resemble unicellular algae. The loss of protein farnesylation is not as severe but also results in polar cell elongation and differentiation defects. The complete loss of Rab-geranylgeranyltransferase activity appears to be lethal in P. patens. Labeling with antibodies to cell wall components support the lack of polarity establishment and the undifferentiated state of geranylgeranyltransferase type I mutant plants. Our results show that prenylated proteins play key roles in P. patens development and differentiation processes.
Ghana's GMO debates: beyond the sticking points (3) GhanaWeb The foregoing explains why some scientists argue that the assumption that conventionally-bred crops are necessarily safer than GM crops is overly simplistic, especially when...
The composition of betalain, red or yellow pigments, and betaine (trimethylglycine or glycinebetaine) of nine beetroot (Beta vulgaris L.) cultivars produced in the greenhouse or field was studied. Inhibition of HepG2 cell proliferation by betanin and betaine was also tested. Four predominant betalains, two betacyanins (betanin and isobetanin) and two betaxanthins (vulgaxanthin I and miraxanthin V), were isolated and quantified. Betanin and vulgaxanthin I were the major compounds in red and yellow beetroot extracts, respectively, and they comprised >90% of the betalain content in the tested cultivars. The total betalain content of beetroots produced from the field was between 650 and 800 μg/g fresh weight, approximately 25% higher than those from the greenhouse. The betaine content of the beetroot grown in the field was between 3.0 and 4.8 mg/g fresh weight, approximately 20% higher than in plants from the greenhouse. There was great variation among the cultivars with respect to their contents of betalains and betaine. In vitro cancer cell cytotoxicity was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay on HepG2 cells after exposure to betanin and betaine at concentrations ranging from 0 to 400 μg/mL and from 0 to 800 μg/mL for 48 h, respectively. Betanin resulted in a 49% inhibition of HepG2 cell proliferation at 200 μg/mL, and betaine yielded a 25% inhibition at 800 μg/mL, implying a higher cytotoxicity of betanin compared with betaine. The results indicated that the contents of health-beneficial compounds in beetroots, betalains and betaine, could be increased by modifying the growing conditions and that betanin and betaine extracted from beetroots had some anticancer effects against HepG2 cells.
Infectious Disease Medical Article: Engineering, expression in transgenic plants and characterisation of e559, a rabies virus-neutralising monoclonal antibody (Engineering, expression in transgenic plants and characterisation of e559, a rabies...
The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing‐sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance.
Quantifying the impact of heritable epigenetic variation on complex traits is an emerging challenge in population genetics. Here, we analyze a population of isogenic Arabidopsis lines that segregate experimentally induced DNA methylation changes at hundreds of regions across the genome. We demonstrate that several of these differentially methylated regions (DMRs) act as bona fide epigenetic quantitative trait loci (QTLepi), accounting for 60 to 90% of the heritability for two complex traits, flowering time and primary root length. These QTLepi are reproducible and can be subjected to artificial selection. Many of the experimentally induced DMRs are also variable in natural populations of this species and may thus provide an epigenetic basis for Darwinian evolution independently of DNA sequence changes.
Vitamin A enriched rice (Golden Rice) is a cost-efficient solution that can substantially reduce health costs. Despite Golden Rice being available since early 2000, this rice has not been introduced in any country. Governments must perceive additional costs that overcompensate the benefits of the technology to explain the delay in approval. We develop a real option model including irreversibility and uncertainty about perceived costs and arrival of new information to explain a delay in approval. The model has been applied to the case of India. Results show the annual perceived costs have to be at least US$199 million per year approximately for the last decade to explain the delay in approval of the technology. This is an indicator of the economic power of the opposition towards Golden Rice resulting in about 1.4 million life years lost over the past decade in India.
The narrowing of diversity in crop species contributing to the world’s food supplies has been considered a potential threat to food security. However, changes in this diversity have not been quantified globally. We assess trends over the past 50 y in the richness, abundance, and composition of crop species in national food supplies worldwide. Over this period, national per capita food supplies expanded in total quantities of food calories, protein, fat, and weight, with increased proportions of those quantities sourcing from energy-dense foods. At the same time the number of measured crop commodities contributing to national food supplies increased, the relative contribution of these commodities within these supplies became more even, and the dominance of the most significant commodities decreased. As a consequence, national food supplies worldwide became more similar in composition, correlated particularly with an increased supply of a number of globally important cereal and oil crops, and a decline of other cereal, oil, and starchy root species. The increase in homogeneity worldwide portends the establishment of a global standard food supply, which is relatively species-rich in regard to measured crops at the national level, but species-poor globally. These changes in food supplies heighten interdependence among countries in regard to availability and access to these food sources and the genetic resources supporting their production, and give further urgency to nutrition development priorities aimed at bolstering food security.
Stem cells self-renew and produce cells that differentiate to become the source of the plant body. The moss Physcomitrella patens forms eight types of stem cells during its life cycle and serves as a useful model in which to explore the evolution of such cells. The common ancestor of land plants is inferred to have been haplontic and to have formed stem cells only in the gametophyte generation. A single stem cell would have been maintained in the ancestral gametophyte meristem, as occurs in extant basal land plants. During land plant evolution, stem cells diverged in the gametophyte generation to form different types of body parts, including the protonema and rhizoid filaments, leafy-shoot and thalloid gametophores, and gametangia formed in moss. A simplex meristem with a single stem cell was acquired in the sporophyte generation early in land plant evolution. Subsequently, sporophyte stem cells became multiple in the meristem and were elaborated further in seed plant lineages, although the evolutionary origin of niche cells, which maintain stem cells is unknown. Comparisons of gene regulatory networks are expected to give insights into the general mechanisms of stem cell formation and maintenance in land plants and provide information about their evolution. P. patens develops at least seven types of simplex meristem in the gametophyte and at least one type in the sporophyte generation and is a good material for regulatory network comparisons. In this review, we summarize recently revealed molecular mechanisms of stem cell initiation and maintenance in the moss.
Various gene networks involve AIL genes to steer plant development.
AILs regulate embryogenesis, meristem development, organ initiation and growth.
AILs interact with auxin pathways at multiple levels throughout plant development.
AIL proteins exert their functions in a dosage-dependent manner.
Members of the AINTEGUMENTA-LIKE (AIL) family of APETALA 2/ETHYLENE RESPONSE FACTOR (AP2/ERF) domain transcription factors are expressed in all dividing tissues in the plant, where they have central roles in developmental processes such as embryogenesis, stem cell niche specification, meristem maintenance, organ positioning, and growth. When overexpressed, AIL proteins induce adventitious growth, including somatic embryogenesis and ectopic organ formation. The Arabidopsis (Arabidopsis thaliana) genome contains eight AIL genes, including AINTEGUMENTA, BABY BOOM, and the PLETHORA genes. Studies on these transcription factors have revealed their intricate relationship with auxin as well as their involvement in an increasing number of gene regulatory networks, in which extensive crosstalk and feedback loops have a major role.
Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology.
The Hindu Regulating genetic modification The Hindu This gives the Indian Council of Agricultural Research (ICAR), Department of Biotechnology (DBT), Indian Council of Medical Research (ICMR), Council of Scientific & Industrial Research (CSIR), the...
As a developing country with relatively limited arable land, China is making great efforts for development and use of genetically modified (GM) crops to boost agricultural productivity. Many GM crop varieties have been developed in China in recent years; in particular, China is playing a leading role in development of insect-resistant GM rice lines. To ensure the safe use of GM crops, biosafety risk assessments are required as an important part of the regulatory oversight of such products. With over 20 years of nationwide promotion of agricultural biotechnology, a relatively well-developed regulatory system for risk assessment and management of GM plants has been developed that establishes a firm basis for safe use of GM crops. So far, a total of seven GM crops involving ten events have been approved for commercial planting, and 5 GM crops with a total of 37 events have been approved for import as processing material in China. However, currently only insect-resistant Btcotton and disease-resistant papaya have been commercially planted on a large scale. The planting of Bt cotton and disease-resistant papaya have provided efficient protection against cotton bollworms and Papaya ringspot virus (PRSV), respectively. As a consequence, chemical application to these crops has been significantly reduced, enhancing farm income while reducing human and non-target organism exposure to toxic chemicals. This article provides useful information for the colleagues, in particular for them whose mother tongue is not Chinese, to clearly understand the biosafety regulation and commercial use of genetically modified crops in China.
Essentially all plant species exhibit heritable genetic variation for resistance to a variety of plant diseases caused by fungi, bacteria, oomycetes or viruses. Disease losses in crop monocultures are already significant, and would be greater but for applications of disease-controlling agrichemicals. For sustainable intensification of crop production, we argue that disease control should as far as possible be achieved using genetics rather than using costly recurrent chemical sprays. The latter imply CO2 emissions from diesel fuel and potential soil compaction from tractor journeys. Great progress has been made in the past 25 years in our understanding of the molecular basis of plant disease resistance mechanisms, and of how pathogens circumvent them. These insights can inform more sophisticated approaches to elevating disease resistance in crops that help us tip the evolutionary balance in favour of the crop and away from the pathogen. We illustrate this theme with an account of a genetically modified (GM) blight-resistant potato trial in Norwich, using the Rpi-vnt1.1 gene isolated from a wild relative of potato, Solanum venturii, and introduced by GM methods into the potato variety Desiree.
Agriculture arose during a period of profound global climatic and ecological change following the end of the Pleistocene. Yet, the role of phenotypic plasticity – an organism's ability to change its phenotype in response to the environment – and environmental influences in the dramatic phenotypic transformations that occurred during plant domestication are poorly understood. Another factor possibly influential in agricultural origins, the productivity of crop plant wild progenitors in Late Pleistocene vs. Holocene environments, has received increasing attention recently and merits further investigation. In this study, we examined phenotypic characteristics and productivity (biomass, seed yield) in the wild progenitor of maize, the teosinte Zea mays ssp. parviglumis H.H. Iltis & Doebley, when it was first exploited and cultivated by growing it in atmospheric CO2 concentrations and temperatures characteristic of the late-glacial and early Holocene periods. Plants responded with a number of attributes uncharacteristic of teosinte in today's environments, including maize-type traits in vegetative architecture, inflorescence sexuality, and seed maturation. Teosinte productivity was significantly lower in late-glacial compared with early Holocene and modern environments. Our evidence indicates that: a) ancestral biological characteristics of crop plant progenitors aren't always predicted from living examples, b) some important maize phenotypic traits were present at initial human exploitation and selection, and c) Pleistocene plant productivity should be considered a significant factor in the chronology of food production origins.
Rose scent in poplar trees? WSU turns to genetic engineering The Seattle Times “We've been trying for many decades to understand how plants make these special chemicals that can be used in flavorings, fuels and medicinals, and that seemed like the...
Cornell Chronicle Predators delay pest resistance to Bt crops Cornell Chronicle Co-authors include Elizabeth Earle, Cornell professor emeritus of plant breeding and genetics, who developed the Bt broccoli; Richard Roush, a researcher at the...