plant cell genetics
14.7K views | +2 today
Follow
 
Scooped by Jean-Pierre Zryd
onto plant cell genetics
Scoop.it!

Pitt biologist receives $2 million to study genetic diversity of plants worldwide

Although polyploids, which are plants with more than two sets of chromosomes, are common, how they contribute to the biodiversity has remained a mystery -- until now.
more...
No comment yet.
plant cell genetics
Your new post is loading...
Your new post is loading...
Rescooped by Jean-Pierre Zryd from Food Policy
Scoop.it!

The global burden of chronic and hidden hunger: Trends and determinants - Elsevier 

The global burden of chronic and hidden hunger: Trends and determinants - Elsevier  | plant cell genetics | Scoop.it

Eradicating hunger in all its forms, including chronic and hidden hunger, requires good understanding of the problem's magnitude, trends, and determinants. Existing studies measure “hunger” through proxies that all have shortcomings. 


We use a more comprehensive metric, Disability-Adjusted Life Years (DALYs), to quantify the burden of hunger and show related trends. While the burden of chronic hunger more than halved since 1990, it remains larger than the burden of hidden hunger. 


Cross-country regressions show that economic growth was a major determinant of reducing the hunger burden. However... determinants have larger effects on the burden of chronic hunger than on the burden of hidden hunger. Complementary micro-level interventions are required to end hunger in all its forms. 


Open Access: https://doi.org/10.1016/j.gfs.2018.03.004



Via Alexander J. Stein
more...
Alexander J. Stein's curator insight, April 2, 8:38 AM
 
So far “hunger” was measured by looking at how much calories are available per capita (at the national or household level). However, this ignores distributional issues, it also ignores that an outcome like hunger cannot necessarily be equated directly with one single input like calories, and it ignores the importance of other nutrients. Alternatively “hunger” was measured by looking at the prevalence of anthropometric outcomes such as stunting. However, this ignores that not all forms of hunger lead to stunting and that stunting is not only caused by hunger, and by using a head-count approach it also ignores that the “depth” of the problem can change (looking how many people are affected doesn’t say much about how much they are suffering). Index measures that combine the above information suffer from the same shortcomings. Therefore we used a comprehensive measure of “hunger” that looks at the outcomes of malnutrition in all the relevant nutrients. 

We found that over time (calorie-related) chronic hunger is falling much faster than (micronutrient-related) hidden hunger: Between 1990 and 2010 the global burden of chronic hunger fell by 50%, while the burden of hidden hunger fell only by 30%. In terms of what is driving these developments – and what might be used as levers by policy-makers – economic growth has been a key factor, while other factors contributing to a reduction of hunger were urbanisation, democracy, clement climate, larger food supplies and diversity, female schooling, and access to improved sanitation and health care. However, these factors worked much stronger for chronic hunger than for hidden hunger. This means that to address hunger in general, and chronic hunger in particular (one of the Sustainable Development Goals), one strategy might be to promote economic growth, supported by measures aiming at strengthening the other factors (where possible). However to address hidden hunger (micronutrient malnutrition), more specific measures are needed – such as biofortification, food fortification, or dietary supplementation. 
 
Alexander J. Stein's curator insight, April 2, 5:10 PM
 
So far “hunger” was measured by looking at how much calories are available per capita (at the national or household level). However, this ignores distributional issues, it also ignores that a complex outcome like hunger cannot necessarily be equated directly with one single input like calories, and it ignores the importance of other nutrients. Alternatively “hunger” was measured by looking at the prevalence of anthropometric outcomes such as stunting. However, this ignores that not all forms of hunger lead to stunting and that stunting is not only caused by hunger, and by using a head-count approach it also ignores that the “depth” of the problem can change (looking how many people are affected doesn’t say much about how much they are suffering). Index measures that combine the above information suffer from the same shortcomings. Therefore we used DALYs, a comprehensive measure (also) of “hunger” that looks at the outcomes of malnutrition in all the relevant nutrients. 

We found that over time (calorie-related) chronic hunger is falling much faster than (micronutrient-related) hidden hunger: Between 1990 and 2010 the global burden of chronic hunger fell by 50%, while the burden of hidden hunger fell only by 30%. In terms of what is driving these developments – and what might be used as levers by policy-makers – economic growth has been a key factor, while other factors contributing to a reduction of hunger were urbanisation, democracy, clement climate, larger food supplies and diversity, female schooling, and access to improved sanitation and health care. However, these factors worked much stronger for chronic hunger than for hidden hunger. This means that to address hunger in general, and chronic hunger in particular (one of the Sustainable Development Goals), one strategy might be to promote economic growth, supported by measures aiming at strengthening the other factors (where possible). However to address hidden hunger (micronutrient malnutrition), more specific measures are needed – such as biofortification, food fortification, or dietary supplementation. 
 
Scooped by Jean-Pierre Zryd
Scoop.it!

Sowing the seeds of skepticism: Russian state news and anti-GMO sentiment

Sowing the seeds of skepticism: Russian state news and anti-GMO sentiment | plant cell genetics | Scoop.it
Biotech news coverage in English-language Russian media fits the profile of the Russian information warfare strategy described in recent military reports. This raises the question of whether Russia views the dissemination of anti-GMO information as just one of many divisive issues it can exploit as part of its information war, or if GMOs serve more expansive disruptive purposes. Distinctive patterns in Russian news provide evidence of a coordinated information campaign that could turn public opinion against genetic engineering. The recent branding of Russian agriculture as the ecologically clean alternative to genetically engineered foods is suggestive of an economic motive behind the information campaign against western biotechnologies.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Retrotransposons Control Fruit-Specific, Cold-Dependent Accumulation of Anthocyanins in Blood Oranges

Retrotransposons Control Fruit-Specific, Cold-Dependent Accumulation of Anthocyanins in Blood Oranges | plant cell genetics | Scoop.it

Traditionally, Sicilian blood oranges (Citrus sinensis) have been associated with cardiovascular health, and consumption has been shown to prevent obesity in mice fed a high-fat diet. Despite increasing consumer interest in these health-promoting attributes, production of blood oranges remains unreliable due largely to a dependency on cold for full color formation. We show that Sicilian blood orange arose by insertion of a Copia-like retrotransposon adjacent to a gene encoding Ruby, a MYB transcriptional activator of anthocyanin production. The retrotransposon controls Ruby expression, and cold dependency reflects the induction of the retroelement by stress. A blood orange of Chinese origin results from an independent insertion of a similar retrotransposon, and color formation in its fruit is also cold dependent. Our results suggest that transposition and recombination of retroelements are likely important sources of variation in Citrus.

more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Diffusible repression of cytokinin signalling produces endodermal symmetry and passage cells

Diffusible repression of cytokinin signalling produces endodermal symmetry and passage cells | plant cell genetics | Scoop.it

In vascular plants, the root endodermis surrounds the central vasculature as a protective sheath that is analogous to the polarized epithelium in animals, and contains ring-shaped Casparian strips that restrict diffusion1. After an initial lag phase, individual endodermal cells suberize in an apparently random fashion to produce ‘patchy’ suberization that eventually generates a zone of continuous suberin deposition2. Casparian strips and suberin lamellae affect paracellular and transcellular transport, respectively. Most angiosperms maintain some isolated cells in an unsuberized state3 as so-called ‘passage cells’, which have previously been suggested to enable uptake across an otherwise-impermeable endodermal barrier3,4. Here we demonstrate that these passage cells are late emanations of a meristematic patterning process that reads out the underlying non-radial symmetry of the vasculature. This process is mediated by the non-cell-autonomous repression of cytokinin signalling in the root meristem, and leads to distinct phloem- and xylem-pole-associated endodermal cells. The latter cells can resist abscisic acid-dependent suberization to produce passage cells. Our data further demonstrate that, during meristematic patterning, xylem-pole-associated endodermal cells can dynamically alter passage-cell numbers in response to nutrient status, and that passage cells express transporters and locally affect the expression of transporters in adjacent cortical cells.

more...
No comment yet.
Rescooped by Jean-Pierre Zryd from Food & Economics
Scoop.it!

Trait Valuation in Genetically Modified Crops: An ex-ante Analysis of GM Cassava against Cassava Mosaic Disease

Cassava is a widely distributed crop known for food security and industrial applications. Nonetheless, it is highly prone to attacks of pests and diseases. Cassava mosaic disease (CMD) is an important cause of loss across the globe. In this context, research is focused on developing cassava mosaic disease resistant varieties through transgenic and conventional approaches. 


In this paper, the trait of CMD resistance is valued ex-ante using partial budget approach and economic surplus model. The trait value of CMD resistance at farm level varies from $600 per hectare in drip-irrigated production system to $240 per hectare in rainfed production system. At the macro level, the value of the improved trait is worth $72 million. The results clearly indicate attractive rate of returns on investment in research for CMD resistance in cassava. 


http://doi.org/10.5958/0974-0279.2017.00044.1



Via Alexander J. Stein
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

RecQ helicases function in development, DNA repair, and gene targeting in Physcomitrella patens

RecQ helicases function in development, DNA repair, and gene targeting in Physcomitrella patens | plant cell genetics | Scoop.it
RecQ DNA helicases are genome surveillance proteins found in all kingdoms of life. They are characterized best in humans, as mutations in RecQ genes lead to developmental abnormalities and diseases. To better understand RecQ-functions in plants we concentrated on Arabidopsis thaliana and Physcomitrella patens, the model species predominantly used for studies on DNA repair and gene targeting. Phylogenetic analysis of the six P. patens RecQ genes revealed their orthologs in humans and plants. Because A. thaliana and P. patens differ in their RecQ4 and RecQ6 genes, reporter and deletion moss mutants were generated and gene functions studied in reciprocal cross-species and cross-kingdom approaches. Both proteins can be found in meristematic moss tissues, although at low levels and with distinct expression patterns. PpRecQ4 is involved in embryogenesis and in subsequent development as demonstrated by sterility of PpRecQ4 mutants and by morphological aberrations. Additionally, PpRecQ4 displays an increased sensitivity to DNA damages and an increased rate of gene targeting. Therefore, we conclude that PpRecQ4 acts as a repressor of recombination. In contrast, PpRecQ6 is not obviously important for moss development or DNA repair but does function as a potent enhancer of gene targeting.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Relative deployment rates of renewable and nuclear power: A cautionary tale of two metrics

Nothing to do with plant genetics, but our future should avoid the danger of nuclear energy & its genetic risks ...  !!!
Which can more quickly displace fossil-fueled electricity generation—nuclear power or modern renewables? Contrary to a persistent myth based on erroneous methods, global data show that renewable electricity adds output and saves carbon faster than nuclear power does or ever has. However, some literature asserts the contrary, based on a peculiar per-capita metric—perhaps useful for comparing countries but not technologies —applied to selected countries while ignoring others with the opposite outcome. Further flaws include cherrypicked and incomplete data, restrictive redefinitions, inconsistent comparisons, and omitted institutional lead times and dry-hole risks. Careful dissection of the reasons for contradictory results (even within the same paper) from absolute and per-capita metrics of growth in carbon-free electricity generation reveals the need for care in calculating and assessing claims about which technologies can and do deploy most quickly.
more...
No comment yet.
Rescooped by Jean-Pierre Zryd from GMOs, NBT & Sustainable agriculture
Scoop.it!

Sweet transgenic immunity

Sweet transgenic immunity | plant cell genetics | Scoop.it
Banana is not just every kid’s favourite fruit; it is also a major staple crop that feeds (directly or indirectly) half a billion people in (sub)tropical areas. Unfortunately, banana is once again threatened by Fusarium wilt, a devastating fungal disease. A mostly Australian team has now used biotechnology to create a transgenic resistant banana. Credit: David Hancock/Alamy Stock Photo Last century, the Gros Michel cultivar was decimated by the same disease, and replaced by the resistant Cavendish — the fruit most of us are familiar with. But Cavendish is no match for a new Fusarium race now spreading in Asia and Africa, causing fears over what may happen when the disease reaches Latin America, the most important region of production. No chemical treatment is efficient, and spores can stay dormant in the soil for decades. As in the case of the Hawaiian papaya, saved from the ringspot virus by a transgenic approach, the authors thought to use biotechnology to increase banana resistance to the disease. The researchers overexpressed two genes, including one nucleotide-binding/leucine-rich repeat (NB-LRR) gene called RGA2 from a resistant wild banana. Unlike previous research performed in a glasshouse, the transformed lines were tested in a heavily contaminated field. The results after three years were impressive: while most of the control plants were dead or infected, the plants highly expressing RGA2 were completely immune to the disease, without any detrimental effect on yield. Even more interesting from a regulatory and public acceptance point of view, the cultivated banana already contains a weakly expressed RGA2 homologue; therefore slightly modifying the endogenous gene may lead to the same level of resistance. This success story in the making is another reminder of the power of crop biotechnology as a tool to improve food security.

Via Christophe Jacquet
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Impact of genetically engineered maize on agronomic, environmental and toxicological traits: a meta-analysis of 21 years of field data

Impact of genetically engineered maize on agronomic, environmental and toxicological traits: a meta-analysis of 21 years of field data | plant cell genetics | Scoop.it

Despite the extensive cultivation of genetically engineered (GE) maize and considerable number of scientific reports on its agro-environmental impact, the risks and benefits of GE maize are still being debated and concerns about safety remain. This meta-analysis aimed at increasing knowledge on agronomic, environmental and toxicological traits of GE maize by analyzing the peer-reviewed literature (from 1996 to 2016) on yield, grain quality, non-target organisms (NTOs), target organisms (TOs) and soil biomass decomposition. Results provided strong evidence that GE maize performed better than its near isogenic line: grain yield was 5.6 to 24.5% higher with lower concentrations of mycotoxins (−28.8%), fumonisin (−30.6%) and thricotecens (−36.5%). The NTOs analyzed were not affected by GE maize, except for Braconidae, represented by a parasitoid of European corn borer, the target of Lepidoptera active Bt maize. Biogeochemical cycle parameters such as lignin content in stalks and leaves did not vary, whereas biomass decomposition was higher in GE maize. The results support the cultivation of GE maize, mainly due to enhanced grain quality and reduction of human exposure to mycotoxins. Furthermore, the reduction of the parasitoid of the target and the lack of consistent effects on other NTOs are confirmed.

more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Transcriptome dynamics at Arabidopsis graft junctions reveal an intertissue recognition mechanism that activates vascular regeneration

Transcriptome dynamics at Arabidopsis graft junctions reveal an intertissue recognition mechanism that activates vascular regeneration | plant cell genetics | Scoop.it
Plant grafting is an ancient and agriculturally important technique. Despite its widespread use, little is known about how plants graft. Here, we perform a genome-wide transcriptome analysis of tissues above and below graft junctions. We observed a sequential activation of genes important for vascular development including cambium-, phloem-, and xylem-related genes. Massive changes in gene expression that rapidly differentiate the top of the graft from the bottom occur. These changes disappear as the graft heals and the vasculature reconnects. Many genes below the junction rapidly respond to the presence of attached tissues including genes involved in vascular differentiation and cell division. This intertissue communication process occurs independently of functional vascular connections and acts as a signal to activate vascular regeneration.

The ability for cut tissues to join and form a chimeric organism is a remarkable property of many plants; however, grafting is poorly characterized at the molecular level. To better understand this process, we monitored genome-wide gene expression changes in grafted Arabidopsis thaliana hypocotyls. We observed a sequential activation of genes associated with cambium, phloem, and xylem formation. Tissues above and below the graft rapidly developed an asymmetry such that many genes were more highly expressed on one side than on the other. This asymmetry correlated with sugar-responsive genes, and we observed an accumulation of starch above the graft junction. This accumulation decreased along with asymmetry once the sugar-transporting vascular tissues reconnected. Despite the initial starvation response below the graft, many genes associated with vascular formation were rapidly activated in grafted tissues but not in cut and separated tissues, indicating that a recognition mechanism was activated independently of functional vascular connections. Auxin, which is transported cell to cell, had a rapidly elevated response that was symmetric, suggesting that auxin was perceived by the root within hours of tissue attachment to activate the vascular regeneration process. A subset of genes was expressed only in grafted tissues, indicating that wound healing proceeded via different mechanisms depending on the presence or absence of adjoining tissues. Such a recognition process could have broader relevance for tissue regeneration, intertissue communication, and tissue fusion events.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Meeting report: Separate product from process: framing the debate that surrounds the potential uptake of new breeding technologies

Meeting report: Separate product from process: framing the debate that surrounds the potential uptake of new breeding technologies | plant cell genetics | Scoop.it

The use of the CRISPR-Cas9 system for precision genome editing (GE) has been regularly described as a ‘game-changing technology’ that allows a more precise targeting of DNA to induce specific nucleotide variations (Belhaj et al. 2015); however, the use of GE in plants for the production of food or feed still faces an uncertain regulatory future. This follows on from a long-standing public distrust of genetically modified organisms (GMOs), an opinion predicated from, amongst other things, controversial yet discredited scientific studies and public miscommunications. Public unease with this technology has guided government policy on the permitted uses of the products of GMOs, such that growth of these crops is now restricted throughout most of the European Union (EU). The plant science community stands at an important crossroads at which the future uses of plants generated by GE technologies will be decided..

more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

The push and pull of plant specialized metabolism underlies a long‐standing, colorful mystery

The push and pull of plant specialized metabolism underlies a long‐standing, colorful mystery | plant cell genetics | Scoop.it


This article is a Commentary on Lopez‐Nieves et al., 217: 896–908.

Three types of compounds – chlorophylls, carotenoids and anthocyanins – are responsible for generating the vast majority of colors in the plant world. However, in 1918, a PhD student working with Richard Willstätter – the 1915 Chemistry Nobel Prize Winner who studied chlorophyll – recognized that the red color in beets is different (Ainley & Robinson, 1937). The red, purple and blue colors in many plants are a result of accumulation of anthocyanins, which lack nitrogen. However, the red pigment in beets – composed of the compound betanin – was found to contain nitrogen. Betanin soon came to be annotated (Ainley & Robinson, 1937) – with some suspicion (Pucher et al., 1938) – as a ‘nitrogenous anthocyanin’, with one or more amino acids conjugated to an anthocyanin backbone. However, this inference was proved incorrect when, in 1957, it was demonstrated that the nitrogen in betanin was actually contained in a pyrrole ring and not in a conjugated amino acid (Peterson & Joslyn, 1958). This intriguing difference between

more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Speed breeding is a powerful tool to accelerate crop research and breeding

Speed breeding is a powerful tool to accelerate crop research and breeding | plant cell genetics | Scoop.it

The growing human population and a changing environment have raised significant concern for global food security, with the current improvement rate of several important crops inadequate to meet future demand1. This slow improvement rate is attributed partly to the long generation times of crop plants. Here, we present a method called ‘speed breeding’, which greatly shortens generation time and accelerates breeding and research programmes. Speed breeding can be used to achieve up to 6 generations per year for spring wheat (Triticum aestivum), durum wheat (T. durum), barley (Hordeum vulgare), chickpea (Cicer arietinum) and pea (Pisum sativum), and 4 generations for canola (Brassica napus), instead of 2–3 under normal glasshouse conditions. We demonstrate that speed breeding in fully enclosed, controlled-environment growth chambers can accelerate plant development for research purposes, including phenotyping of adult plant traits, mutant studies and transformation. The use of supplemental lighting in a glasshouse environment allows rapid generation cycling through single seed descent (SSD) and potential for adaptation to larger-scale crop improvement programs. Cost saving through light-emitting diode (LED) supplemental lighting is also outlined. We envisage great potential for integrating speed breeding with other modern crop breeding technologies, including high-throughput genotyping, genome editing and genomic selection, accelerating the rate of crop improvement.

more...
No comment yet.
Rescooped by Jean-Pierre Zryd from Plant pathogenic fungi
Scoop.it!

The origin and evolution of mycorrhizal symbioses: from palaeomycology to phylogenomics - Strullu‐Derrien - - New Phytologist - Wiley Online Library

The origin and evolution of mycorrhizal symbioses: from palaeomycology to phylogenomics - Strullu‐Derrien - - New Phytologist - Wiley Online Library | plant cell genetics | Scoop.it
The ability of fungi to form mycorrhizas with plants is one of the most remarkable and enduring adaptations to life on land. The occurrence of mycorrhizas is now well established in c. 85% of extant plants, yet the geological record of these associations is sparse. Fossils preserved under exceptional conditions provide tantalizing glimpses into the evolutionary history of mycorrhizas, showing the extent of their occurrence and aspects of their evolution in extinct plants. The fossil record has important roles to play in establishing a chronology of when key fungal associations evolved and in understanding their importance in ecosystems through time. Together with calibrated phylogenetic trees, these approaches extend our understanding of when and how groups evolved in the context of major environmental change on a global scale. Phylogenomics furthers this understanding into the evolution of different types of mycorrhizal associations, and genomic studies of both plants and fungi are shedding light on how the complex set of symbiotic traits evolved. Here we present a review of the main phases of the evolution of mycorrhizal interactions from palaeontological, phylogenetic and genomic perspectives, with the aim of highlighting the potential of fossil material and a geological perspective in a cross‐disciplinary approach.

Via Jonathan Plett, Steve Marek
more...
No comment yet.
Rescooped by Jean-Pierre Zryd from Plant immunity and legume symbiosis
Scoop.it!

Leaf nodule symbiosis: function and transmission of obligate bacterial endophytes - ScienceDirect

Leaf nodule symbiosis: function and transmission of obligate bacterial endophytes - ScienceDirect | plant cell genetics | Scoop.it
Various plant species establish intimate symbioses with bacteria within their aerial organs. The bacteria are contained within nodules or glands often present in distinctive patterns on the leaves, and have been used as taxonomic marker since the early 20th century. These structures are present in very diverse taxa, including dicots (Rubiaceae and Primulaceae) and monocots (Dioscorea). The symbionts colonize the plants throughout their life cycles and contribute bioactive secondary metabolites to the association. In this review, we present recent progress in the understanding of these plant–bacteria symbioses, including the modes of transmission, distribution and roles of the symbionts.

Via Christophe Jacquet
more...
No comment yet.
Rescooped by Jean-Pierre Zryd from Plant pathogenic fungi
Scoop.it!

Symbiosis genes for immunity and vice versa

Symbiosis genes for immunity and vice versa | plant cell genetics | Scoop.it

Highlights

• Several LysM receptor proteins have a dual function in symbiosis and immunity.
• Symbiotic transcription factors can also control pathogen infection.
• Genes of hormonal pathways regulate both pathogen and symbiont colonisation.
• Crosstalk between symbiosis and immunity also occurs within the flavonoid pathway.

Basic molecular knowledge on plant–pathogen interactions has largely been gained from reverse and forward genetics in Arabidopsis thaliana. However, as this model plant is unable to establish endosymbiosis with mycorrhizal fungi or rhizobia, plant responses to mutualistic symbionts have been studied in parallel in other plant species, mainly legumes. The resulting analyses led to the identification of gene networks involved in various functions, from microbe recognition to signalling and plant responses, thereafter assigned to either mutualistic symbiosis or immunity, according to the nature of the initially inoculated microbe. The increasing development of new pathosystems and genetic resources in model legumes and the implementation of reverse genetics in plants such as rice and tomato that interact with both mycorrhizal fungi and pathogens, have highlighted the dual role of plant genes previously thought to be specific to mutualistic or pathogenic interactions. The next challenges will be to determine whether such genes have similar functions in both types of interaction and if not, whether the perception of microbial compounds or the involvement of specific plant signalling components is responsible for the appropriate plant responses to the encountered microorganisms.


Via Christophe Jacquet, Steve Marek
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Somatic hybridization provides segregating populations for the identification of causative mutations in sterile mutants of the moss Physcomitrella patens - Moody - 2018 - New Phytologist - Wiley On...

Somatic hybridization provides segregating populations for the identification of causative mutations in sterile mutants of the moss Physcomitrella patens - Moody - 2018 - New Phytologist - Wiley On... | plant cell genetics | Scoop.it
Forward genetics is now straightforward in the moss Physcomitrella patens, and large mutant populations can be screened relatively easily. However, perturbation of development before the formation of gametes currently leaves no route to gene discovery. Somatic hybridization has previously been used to rescue sterile mutants and to assign P. patens mutations to complementation groups, but the cellular basis of the fusion process could not be monitored, and there was no tractable way to identify causative mutations. Here we use fluorescently tagged lines to generate somatic hybrids between Gransden (Gd) and Villersexel (Vx) strains of P. patens, and show that hybridization produces fertile diploid gametophytes that form phenotypically normal tetraploid sporophytes. Quantification of genetic variation between the two parental strains reveals single nucleotide polymorphisms at a frequency of 1/286 bp. Given that the genetic distinction between Gd and Vx strains exceeds that found between pairs of strains that are commonly used for genetic mapping in other plant species, the spore populations derived from hybrid sporophytes provide suitable material for bulk segregant analysis and gene identification by genome sequencing.


more...
No comment yet.
Rescooped by Jean-Pierre Zryd from GMOs, NBT & Sustainable agriculture
Scoop.it!

(Occitanie) Les micro-ARN, alternative sérieuse aux engrais chimiques et aux pesticides

(Occitanie) Les micro-ARN, alternative sérieuse aux engrais chimiques et aux pesticides | plant cell genetics | Scoop.it

La start-up toulousaine Micropep Technologies annonce avoir levé 4 millions d’euros auprès d’investisseurs pour développer une méthode innovante de soins des plantes cultivées. Une révolution agronomique est peut-être en marche.

Ce qu'on pensait inutile pourrait malgré tout servir et même avoir un rôle extrêmement positif. C'est la découverte effectuée par le Laboratoire de recherche en sciences végétales (LRSV, unité mixte CNRS/Université de Toulouse) sur le rôle des microARNs publiée dans Nature en 2015.


Présents dans les cellules de la plupart des êtres vivants, les microARNs produisent, au moins chez les plantes, des peptides naturels qui permettent de réguler temporairement l'expression de gènes d'intérêt pouvant agir par exemple sur la germination, la floraison, la fructification, mais aussi sur les défenses contre les attaques de pathogènes. 


L'idée devient évidente : développer une nouvelle génération d'intrants biologiques à partir de ces miPEPs pour diminuer l'utilisation des produits chimiques traditionnellement utilisés en agriculture. C'est devenu l'objectif de Micropep Technologie, la société créée en avril 2016 par Thomas Laurent et les deux principaux chercheurs à l'origine de la découverte, Jean-Philippe Combier et Dominique Lauressergues, avec l'aide de la SATT Toulouse Tech Transfer.


La production des peptides peut s’effectuer soit par voie synthétique par imitation de la molécule, soit par voie biologique en induisant sa fabrication par des bactéries. Les sociétés de capital-risque ne s’y sont pas trompées : 4 millions d’euros ne seront pas de trop, mais le jeu en vaut la chandelle.


Via Isabelle Pélissié, Christophe Jacquet
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Rice Functional Genomics Research: Past Decade and Future

Rice Functional Genomics Research: Past Decade and Future | plant cell genetics | Scoop.it
We review the major advances on rice functional genomics research during the past
10 years, including a summary of functional genomics platforms, genes and molecular
regulatory networks that regulate important agronomic traits, and newly developed
tools for gene identification. Future challenges and prospects of rice functional
genomics research are also discussed.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

The Interrelationships of Land Plants and the Nature of the Ancestral Embryophyte

The Interrelationships of Land Plants and the Nature of the Ancestral Embryophyte | plant cell genetics | Scoop.it

• Early land plant relationships are extremely uncertain • We resolve the “Setaphyta” clade of liverworts plus mosses • The simple body plan of liverworts results from loss of ancestral characters • The ancestral land plant was more complex

more...
No comment yet.
Rescooped by Jean-Pierre Zryd from Agricultural Biodiversity
Scoop.it!

Why a global decline in genetic crop variety matters for the future of food

Why a global decline in genetic crop variety matters for the future of food | plant cell genetics | Scoop.it
Preserving the genetic diversity of edible plants could help us develop new crop varieties, with useful traits such as drought and disease-resistance.
Via Luigi Guarino
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Phytoglobin expression influences soil flooding response of corn plants | Annals of Botany | Oxford Academic

Phytoglobin expression influences soil flooding response of corn plants | Annals of Botany | Oxford Academic | plant cell genetics | Scoop.it
Excess water is a limiting factor for crop productivity. Under conditions of full submergence or flooding, plants can experience prolonged oxygen depletion which compromises basic physiological and biochemical processes. Severe perturbations of the photosynthetic machinery with a concomitant decline in photosynthetic potential as a result of elevated levels of reactive oxygen species (ROS) are the major consequences of water excess. Phytoglobins (Pgbs) are ubiquitous proteins induced by several types of stress which affect plant response by modulating nitric oxide.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Reduction in Root Secondary Growth as a Strategy for Phosphorus Acquisition

Reduction in Root Secondary Growth as a Strategy for Phosphorus Acquisition | plant cell genetics | Scoop.it
We tested the hypothesis that reduced root secondary growth of dicotyledonous species improves phosphorus acquisition. Functional-structural modeling in SimRoot indicates that, in common bean (Phaseolus vulgaris), reduced root secondary growth reduces root metabolic costs, increases root length, improves phosphorus capture, and increases shoot biomass in low-phosphorus soil. Observations from the field and greenhouse confirm that, under phosphorus stress, resource allocation is shifted from secondary to primary root growth, genetic variation exists for this response, and reduced secondary growth improves phosphorus capture from low-phosphorus soil. Under low phosphorus in greenhouse mesocosms, genotypes with reduced secondary growth had 39% smaller root cross-sectional area, 60% less root respiration, 27% greater root length, 78% greater shoot phosphorus content, and 68% greater shoot mass than genotypes with advanced secondary growth. In the field under low phosphorus, these genotypes had 43% smaller root cross-sectional area, 32% greater root length, 58% greater shoot phosphorus content, and 80% greater shoot mass than genotypes with advanced secondary growth. Secondary growth eliminated arbuscular mycorrhizal associations as cortical tissue was destroyed. These results support the hypothesis that reduced root secondary growth is an adaptive response to low phosphorus availability and merits investigation as a potential breeding target.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Why the European Union needs a national GMO opt-in mechanism

On March 27, 2017, the European Union (EU; Brussels) Appeal Committee on Genetically Modified Food and Feed and Environmental Risk voted on draft regulations for approving the placement of three genetically modified (GM) maize events on the market for cultivation in the EU1. The Appeal Committee once again did not reach a qualified majority for either approval or rejection. The March vote result was similar to the preceding vote in the Regulatory Committee 2001/18/EC on January 27, 2017 (ref. 2). This case was the first of its kind since the amendment of the EU legislation on GM crop cultivation (Directive 2015/412, the so-called 'opt-out Directive')3 came into force in 2015. The opt-out Directive allows EU member states to restrict or prohibit cultivation of GM crops in their territory based on “compelling grounds such as those related to: (a) environmental policy objectives; (b) town and country planning; (c) land use; (d) socioeconomic impacts; (e) avoidance of GMO presence in other products [e.g. crops that would be subject to cross-border 'contamination']; (f) agricultural policy objectives; and (g) public policy”3. This possibility was introduced to acknowledge that decisions on the cultivation of GM crops raise complicated issues other than safety, which are best dealt with at a national level and also to improve the process for authorizing GM crops in the EU.

more...
Jonathan Lapleau's curator insight, January 11, 9:20 AM
We need to improve the European regulatory system for GMO, this letter explain why and how.
Scooped by Jean-Pierre Zryd
Scoop.it!

ScienceDirect

ScienceDirect | plant cell genetics | Scoop.it
Highlights • Two novel methods were combined to estimate a realistic worst case hazard index for pesticide residues in the Danish population. • The methods were able to refine previous estimates especially with regard to below LOQ (left censored) data. • Cumulative health risk assessment conducted for the Danish population. • Perspectives on hazard level of pesticides; comparisons with mycotoxins, caffeine and alcohol. Abstract Relatively few studies are available on realistic cumulative risk assessments for dietary pesticide exposure. Despite available studies showing low risk, public concern remains. A method to estimate realistic residue levels based on information from spraying journals and supervised residue trials was described in a previous publication. The present article proposes a new method to estimate average residue levels in imported foods based on residue monitoring data and knowledge about agronomic practices. The two methods were used in combination to estimate average pesticide residue levels in 47 commodities on the Danish market. The chronic consumer exposure was estimated in six Danish diets. The Hazard Index (HI) method was used to assess consumer risk. Despite the conservative (cautious) risk assessment approach, low HI values where obtained. The HI was 16% for adults and 44% for children, combining the risk of all pesticides in the diet. Conclusion: the present study adds support to the evidence showing that adverse health effects of chronic pesticide residue exposure in the Danish population are very unlikely. The HI for pesticides for a Danish adult was on level with that of alcohol for a person consuming the equivalent of 1 glass of wine every seventh year.
more...
No comment yet.