plant cell genetics
12.9K views | +4 today
Follow
plant cell genetics
Your new post is loading...
Your new post is loading...
Scooped by Jean-Pierre Zryd
Scoop.it!

Kinesins Have a Dual Function in Organizing Microtubules during Both Tip Growth and Cytokinesis in Physcomitrella patens

Kinesins Have a Dual Function in Organizing Microtubules during Both Tip Growth and Cytokinesis in Physcomitrella patens | plant cell genetics | Scoop.it

Microtubules (MTs) play a crucial role in the anisotropic deposition of cell wall material, thereby affecting the direction of growth. A wide range of tip-growing cells display highly polarized cell growth, and MTs have been implicated in regulating directionality and expansion. However, the molecular machinery underlying MT dynamics in tip-growing plant cells remains unclear. Here, we show that highly dynamic MT bundles form cyclically in the polarized expansion zone of the moss Physcomitrella patens caulonemal cells through the coalescence of growing MT plus ends. Furthermore, the plant-specific kinesins (KINID1) that are is essential for the proper MT organization at cytokinesis also regulate the turnover of the tip MT bundles as well as the directionality and rate of cell growth. The plus ends of MTs grow toward the expansion zone, and KINID1 is necessary for the stability of a single coherent focus of MTs in the center of the zone, whose formation coincides with the accumulation of KINID1. We propose that KINID-dependent MT bundling is essential for the correct directionality of growth as well as for promoting growth per se. Our findings indicate that two localized cell wall deposition processes, tip growth and cytokinesis, previously believed to be functionally and evolutionarily distinct, share common and plant-specific MT regulatory components.

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

Metabolic engineering approaches for production of biochemicals in food and medicinal plants

Metabolic engineering approaches for production of biochemicals in food and medicinal plants | plant cell genetics | Scoop.it


Metabolic engineering strategies for production of plant natural products.

Methods for genome targeting of mutations and gene insertions.

Recent advances for elucidation of plant secondary biosynthetic pathways.

Metabolic engineering of paclitaxel biosynthesis in vitro.

Production of β-carotene in Golden Rice and other food crops.

 

Historically, plants are a vital source of nutrients and pharmaceuticals. Recent advances in metabolic engineering have made it possible to not only increase the concentration of desired compounds, but also introduce novel biosynthetic pathways to a variety of species, allowing for enhanced nutritional or commercial value. To improve metabolic engineering capabilities, new transformation techniques have been developed to allow for gene specific silencing strategies or stacking of multiple genes within the same region of the chromosome. The ‘omics’ era has provided a new resource for elucidation of uncharacterized biosynthetic pathways, enabling novel metabolic engineering approaches. These resources are now allowing for advanced metabolic engineering of plant production systems, as well as the synthesis of increasingly complex products in engineered microbial hosts. The status of current metabolic engineering efforts is highlighted for the in vitro production of paclitaxel and the in vivoproduction of β-carotene in Golden Rice and other food crops.

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

Beyond the sine law of plant gravitropism

Beyond the sine law of plant gravitropism | plant cell genetics | Scoop.it

The great German plant physiologist Wilhelm Pfeffer rightly claimed that “no plant is entirely without the power of movement” (1). If this fact remains underappreciated, it is perhaps because plant movements typically unfold over minutes, hours, or days, and thus exceed the attention span of all but the most dedicated observer. Among the large array of plant movements, the tropisms—that is, those movements that are directed toward or away from an external stimulus such as gravity or light—are the most fascinating because they highlight beautifully the sentient nature of plants and the goal-directedness of their growth habit. The pervasiveness of plant tropisms is revealed when one stops to consider the unlikeliness that seeds lodged haphazardly within the crevices of a rugged terrain should sprout stems that reliably find their way up. Were it not for the ability of the young plants to sense light and gravity, forests would be impenetrable tangles of stems and branches growing in all directions. Their prevalence in the plant kingdom explains why tropisms have been an active area of research since the beginning of the 19th century. By the end of the 19th century, the field had reached such a level of development and popularity that eminent biologists, including Charles Darwin and Pfeffer, could devote entire books to the topic (1, 2). Given this long and illustrious tradition of research, one might expect today’s biologists to have extracted all useful information from standard observational research of plant tropisms. A paper published in PNAS should convince the readers that much can still be learned from careful, quantitative observation of biological processes. In a systematic study of shoot gravitropism in 11 taxa, Bastien et al. (3) at once establish the universal response to gravity as a process of initial stem curving followed by apical straightening and debunk the idea that current models of gravitropism offer a plausible explanation for the process.

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

A robust videogrametric method for the velocimetry of wind-induced motion in trees

A robust videogrametric method for the velocimetry of wind-induced motion in trees | plant cell genetics | Scoop.it

Wind has major effect on plants, from growth changes to windbreaks. Therefore, there is a crucial need for non-invasive methods to describe and quantify the complex motion of a plant induced by wind. In this paper two methods based on video sequences analysis are studied. An adaptation of the classical Particle Image Velocimetry method (nat-PIV) is compared with a tracking method based on the optical flow method of Lukas and Kanade, initialized with the features selection method of Shi and Tomasi (ST + KLT). Both methods were benchmarked on an experiment on a walnut tree in open-field conditions submitted to different wind flows at different periods of the year and equipped with 3D magnetic tracking. The metrological assessment was performed in two steps. We first tested if the results given by both methods were significantly different. Secondly, a direct assessment of the two methods versus 3D magnetic tracking was performed. The ST + KLT method proved to be more accurate and robust than nat-PIV one. The outputs of the ST + KLT method are independent of the foliage density, wind velocity and of light gradient intrinsic to outdoor scene. The implementation of ST + KLT method developed for this study in Matlab is freely available.

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

Pine tree yields longest genome ever sequenced - CBS News

Pine tree yields longest genome ever sequenced - CBS News | plant cell genetics | Scoop.it
Pine tree yields longest genome ever sequenced CBS News Understanding the loblolly pine's genetic code could lead to improved breeding of the tree, which is used to make paper and lumber and is being investigated as a potential biofuel, the...
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Flower color as a model system for studies of plant evo-devo

Flower color as a model system for studies of plant evo-devo | plant cell genetics | Scoop.it

Even though pigmentation traits have had substantial impacts on the field of animal evolutionary developmental biology, they have played only relatively minor roles in plant evo-devo. This is surprising given the often direct connection between flower color and fitness variation mediated through the effects of pollinators. At the same time, ecological and evolutionary genetic studies have utilized the molecular resources available for the anthocyanin pathway to generate several examples of the molecular basis of putatively adaptive transitions in flower color. Despite this opportunity to synthesize experimental approaches in ecology, evolution, and developmental biology, the investigation of many fundamental questions in evo-devo using this powerful model is only at its earliest stages. For example, a long-standing question is whether predictable genetic changes accompany the repeated evolution of a trait. Due to the conserved nature of the biochemical and regulatory control of anthocyanin biosynthesis, it has become possible to determine whether, and under what circumstances, different types of mutations responsible for flower color variation are preferentially targeted by natural selection. In addition, because plants use anthocyanin and related compounds in vegetative tissue for other important physiological functions, the identification of naturally occurring transitions from unpigmented to pigmented flowers provides the opportunity to examine the mechanisms by which regulatory networks are co-opted into new developmental domains. Here, we review what is known about the ecological and molecular basis of anthocyanic flower color transitions in natural systems, focusing on the evolutionary and developmental features involved. In doing so, we provide suggestions for future work on this trait and suggest that there is still much to be learned from the evolutionary development of flower color transitions in nature.

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

Du blé génétiquement modifié testé dans un champ en France ? Mais non, en Suisse…

Du blé génétiquement modifié testé dans un champ en France ?  Mais non, en Suisse… | plant cell genetics | Scoop.it
L'Université de Zurich a débuté des premiers essais pour du blé génétiquement modifié afin de résister à l'oïdium, une forme de champignon.

Via Agriculture et Environnement
more...
Agriculture et Environnement's curator insight, March 20, 2014 3:50 AM

#OGM : Du blé génétiquement modifié testé dans un champ en France ?  Mais non, en Suisse…

Rescooped by Jean-Pierre Zryd from Emerging Research in Plant Cell Biology
Scoop.it!

Dissimilarity of contemporary and historical gene flow in a wild carrot (Daucus carota) metapopulation under contrasting levels of human disturbance: implications for risk assessment and management...

Dissimilarity of contemporary and historical gene flow in a wild carrot (Daucus carota) metapopulation under contrasting levels of human disturbance: implications for risk assessment and management... | plant cell genetics | Scoop.it

Background and Aims Transgene introgression from crops into wild relatives may increase the resistance of wild plants to herbicides, insects, etc. The chance of transgene introgression depends not only on the rate of hybridization and the establishment of hybrids in local wild populations, but also on the metapopulation dynamics of the wild relative. The aim of the study was to estimate gene flow in a metapopulation for assessing and managing the risks of transgene introgression.

Methods Wild carrots (Daucus carota) were sampled from 12 patches in a metapopulation. Eleven microsatellites were used to genotype wild carrots. Genetic structure was estimated based on the FST statistic. Contemporary (over the last several generations) and historical (over many generations) gene flow was estimated with assignment and coalescent methods, respectively.

Key Results The genetic structure in the wild carrot metapopulation was moderate (FST = 0·082) and most of the genetic variation resided within patches. A pattern of isolation by distance was detected, suggesting that most of the gene flow occurred between neighbouring patches (≤1 km). The mean contemporary gene flow was 5 times higher than the historical estimate, and the correlation between them was very low. Moreover, the contemporary gene flow in roadsides was twice that in a nature reserve, and the correlation between contemporary and historical estimates was much higher in the nature reserve. Mowing of roadsides may contribute to the increase in contemporary gene flow. Simulations demonstrated that the higher contemporary gene flow could accelerate the process of transgene introgression in the metapopulation.

Conclusions Human disturbance such as mowing may alter gene flow patterns in wild populations, affecting the metapopulation dynamics of wild plants and the processes of transgene introgression in the metapopulation. The risk assessment and management of transgene introgression and the control of weeds need to take metapopulation dynamics into consideration.


Via Jennifer Mach
more...
Rescooped by Jean-Pierre Zryd from Protection phytosanitaire des fruits et légumes
Scoop.it!

Fire-blight resistant apples (ZTH : University of Zurich)

Fire-blight resistant apples (ZTH : University of Zurich) | plant cell genetics | Scoop.it

Researchers from ETH Zurich and the Julius Kühn Institute in Germany have created the first fire-blight-resistant apple. With the aid of so-called cis-genetic engineering, they transfered a resistance gene from a wild apple into the genome of a Gala apple.

A single gene provides a sufficient protection. But more resistance genes are requested to make it doubly sure and to avoid resistance.

The researchers also know that consumers are reluctant to agree with GM techniques. but, as they state “Consumers have to realise that an organically grown Gala apple is treated with copper and sulphur at least twenty-five times, which has a serious impact on the soils, air and groundwater. Scab and fire-blight-resistant cis-gene Gala apples do not have to be treated in this way, making them more environmentally friendly than their bio-counterparts.”


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

Natural Enemies Delay Insect Resistance to Bt Crops

Natural Enemies Delay Insect Resistance to Bt Crops | plant cell genetics | Scoop.it

We investigated whether development of resistance to a Bt crop in the presence of a natural enemy would be slower than without the natural enemy and whether biological control, in conjunction with a Bt crop, could effectively suppress the pest population. Additionally, we investigated whether insecticide-sprayed refuges of non-Bt crops would delay or accelerate resistance to the Bt crop. We used a system of Bt broccoli expressing Cry1Ac, a population of the pest Plutella xylostella with a low frequency of individuals resistant to Cry1Ac and the insecticide spinosad, and a natural enemy, Coleomegilla maculata, to conduct experiments over multiple generations. The results demonstrated that after 6 generations P. xylostella populations were very low in the treatment containing C. maculata and unsprayed non-Bt refuge plants. Furthermore, resistance to Bt plants evolved significantly slower in this treatment. In contrast, Bt plants with no refuge were completely defoliated in treatments without C. maculata after 4–5 generations. In the treatment containing sprayed non-Bt refuge plants and C. maculata, the P. xylostella population was low, although the speed of resistance selection to Cry1Ac was significantly increased. These data demonstrate that natural enemies can delay resistance to Bt plants and have significant implications for integrated pest management (IPM) with Bt crops.


Via Christophe Jacquet
more...
No comment yet.
Rescooped by Jean-Pierre Zryd from Emerging Research in Plant Cell Biology
Scoop.it!

Mapping the Epigenetic Basis of Complex Traits

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.


Via Jennifer Mach
more...
Scooped by Jean-Pierre Zryd
Scoop.it!

Cambridge Journals Online - Environment and Development Economics - Abstract - The economic power of the Golden Rice opposition

Cambridge Journals Online - Environment and Development Economics - Abstract - The economic power of the Golden Rice opposition | plant cell genetics | Scoop.it
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.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Increasing homogeneity in global food supplies and the implications for food security

Increasing homogeneity in global food supplies and the implications for food security | plant cell genetics | Scoop.it

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.

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

Genomic Misconception: a fresh look at the biosafety of transgenic and conventional crops. A plea for a process agnostic regulation


GMO regulation is built on false premises in the EU and the Cartagena biosafety protocols.

Molecular processes of transgenesis and natural mutation are similar.

It is time to change GMO regulation toward a science based product oriented legislation.

Some legislations like the one from Canada rely on Novel crops, conventional or GMOs.

 

The regulation of genetically engineered crops, in Europe and within the legislation of the Cartagena biosafety protocol is built on false premises: The claim was (and unfortunately still is) that there is a basic difference between conventional and transgenic crops, this despite the fact that this has been rejected on scientifically solid grounds since many years. This contribution collects some major arguments for a fresh look at regulation of transgenic crops, they are in their molecular processes of creation not basically different from conventional crops, which are based in their breeding methods on natural, sometimes enhanced mutation. But the fascination and euphoria of the discoveries in molecular biology and the new perspectives in plant breeding in the sixties and seventies led to the wrong focus on transgenic plants alone. In a collective framing process the initial biosafety debates focused on the novelty of the process of transgenesis. When early debates on the risk assessment merged into legislative decisions, this wrong focus on transgenesis alone seemed uncontested. The process-focused view was also fostered by a conglomerate of concerned scientists and biotechnology companies, both with a vested interest to at least tolerate the rise of the safety threshold to secure research money and to discourage competitors of all kinds. Policy minded people and opponent activists without deeper insight in the molecular science agreed to those efforts without much resistance. It is interesting to realize, that the focus on processes was uncontested by a majority of regulators, this despite of serious early warnings from important authorities in science, mainly of US origin. It is time to change the regulation of genetically modified (GM) crops toward a more science based process — agnostic legislation. Although this article concentrates on the critique of the process-oriented regulation, including some details about the history behind, there should be no misunderstanding that there are other important factors responsible for the failure of this kind of process-oriented regulation, most importantly: the predominance of politics in the decision making processes combined with the lack of serious scientific debates on regulatory matters within the European Union and also in the Cartagena system, the obscure and much too complex decision making structures within the EU, and the active, professional, negative and intimidating role of fundamental opposition against GM crops on all levels dealing with flawed science, often declared as better parallel science published by ‘independent’ scientists.

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

Genetically Modified Rice with Health Benefits as a Means to Reduce Micronutrient Malnutrition: Global Status, Consumer Preferences, and Potential Health Impacts of Rice Biofortification - Wheat an...

Abstract

Micronutrient malnutrition, characterized by insufficient intake levels of vitamins and minerals, is a major public health problem that affects about 2 billion people worldwide. In order to reduce the burden of this “hidden hunger”, biofortification is more and more being advocated as an alternative to current micronutrient interventions. Through enhancement of the micronutrient level of staple crops, it could address micronutrient malnutrition where the need is highest. Because staple crops are characterized by low micronutrient concentrations, genetic breeding techniques are often applied to increase levels of specific vitamins, such as folate and provitamin A. This study sheds light on the global status of micronutrient malnutrition, biofortification, and GM biofortified rice as both a GM food product with health benefits and a micronutrient intervention. Thereby, key consumer preference studies and cost-effectiveness analyses on Folate Biofortified Rice and Golden Rice are presented. Support is found for GM biofortified rice as a well-accepted GM food crop and a highly cost-effective health intervention.

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

Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants

Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants | plant cell genetics | Scoop.it

Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone auxin to the lower side is then enhanced, resulting in differential gene expression and cell elongation causing the organ to bend. However, little is known about the dynamics, regulation, and diversity of the entire bending and straightening process. Here, we modeled the bending and straightening of a rod-like organ and compared it with the gravitropism kinematics of different organs from 11 angiosperms. We show that gravitropic straightening shares common traits across species, organs, and orders of magnitude. The minimal dynamic model accounting for these traits is not the widely cited gravisensing law but one that also takes into account the sensing of local curvature, what we describe here as a graviproprioceptive law. In our model, the entire dynamics of the bending/straightening response is described by a single dimensionless “bending number” Bthat reflects the ratio between graviceptive and proprioceptive sensitivities. The parameter B defines both the final shape of the organ at equilibrium and the timing of curving and straightening. B can be estimated from simple experiments, and the model can then explain most of the diversity observed in experiments. Proprioceptive sensing is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies.

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

A Cassava Revolution Could Feed the World's Hungry - Scientific American

Scientific American A Cassava Revolution Could Feed the World's Hungry Scientific American Because many cassava consumers live in developing countries, the plant has not received the intense breeding that has benefited crops more familiar to the...
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

The pollen tube: a soft shell with a hard core - Vogler - 2012 - The Plant Journal - Wiley Online Library

The pollen tube: a soft shell with a hard core - Vogler - 2012 - The Plant Journal - Wiley Online Library | plant cell genetics | Scoop.it

Plant cell expansion is controlled by a fine-tuned balance between intracellular turgor pressure, cell wall loosening and cell wall biosynthesis. To understand these processes, it is important to gain in-depth knowledge of cell wall mechanics. Pollen tubes are tip-growing cells that provide an ideal system to study mechanical properties at the single cell level. With the available approaches it was not easy to measure important mechanical parameters of pollen tubes, such as the elasticity of the cell wall. We used a cellular force microscope (CFM) to measure the apparent stiffness of lily pollen tubes. In combination with a mechanical model based on the finite element method (FEM), this allowed us to calculate turgor pressure and cell wall elasticity, which we found to be around 0.3 MPa and 20–90 MPa, respectively. Furthermore, and in contrast to previous reports, we showed that the difference in stiffness between the pollen tube tip and the shank can be explained solely by the geometry of the pollen tube. CFM, in combination with an FEM-based model, provides a powerful method to evaluate important mechanical parameters of single, growing cells. Our findings indicate that the cell wall of growing pollen tubes has mechanical properties similar to rubber. This suggests that a fully turgid pollen tube is a relatively stiff, yet flexible cell that can react very quickly to obstacles or attractants by adjusting the direction of growth on its way through the female transmitting tissue.

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

Overexpression of epsps transgene in weedy rice: insufficient evidence to support speculations about biosafety - Gressel - 2014 - New Phytologist - Wiley Online Library

Overexpression of epsps transgene in weedy rice: insufficient evidence to support speculations about biosafety - Gressel - 2014 - New Phytologist - Wiley Online Library | plant cell genetics | Scoop.it

The recent paper published in New Phytologist, Wang et al. (2014; this issue pp. 679–683), purports in its title that ‘A novel 5-enolpyruvoylshikimate-3-phosphate (EPSP) synthase transgene for glyphosate resistance stimulates growth and fecundity in weedy rice (Oryza sativa) without herbicide’ and in the paper claims that weedy rice expressing the transgene is more competitively fit than the wild type in the absence of glyphosate treatment. While this may be so, there is a lack of evidence in the paper that the transgene confers glyphosate resistance, or that the transgenic weedy rice is more competitively fit than its wild type. As this paper has generated extensive media coverage facilitated by the authors, we feel it imperative to analyze the paper in depth to ascertain whether the claims made in title, summary, and text have been met, whether criteria necessary for publication have been achieved, as well as whether the media reportage was justified in the form released by the authors.

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

Gene Technology for Papaya Ringspot Virus Disease Management

Gene Technology for Papaya Ringspot Virus Disease Management | plant cell genetics | Scoop.it
The concept of pathogen-derived resistance has been employed for the development of transgenic papaya, using a coat protein-mediated, RNA-silencing mechanism and replicase gene-mediated transformation for effective PRSV disease management.
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Engineering fire blight resistance into the apple cultivar ‘Gala’ using the FB_MR5 CC-NBS-LRR resistance gene of Malus × robusta 5 - Broggini - 2014 - Plant Biotechnology Journal - Wiley Online Lib...

Engineering fire blight resistance into the apple cultivar ‘Gala’ using the FB_MR5 CC-NBS-LRR resistance gene of Malus × robusta 5 - Broggini - 2014 - Plant Biotechnology Journal - Wiley Online Lib... | plant cell genetics | Scoop.it

The fire blight susceptible apple cultivar Malus × domestica Borkh. cv. ‘Gala’ was transformed with the candidate fire blight resistance geneFB_MR5 originating from the crab apple accession Malus × robusta 5 (Mr5). A total of five different transgenic lines were obtained. All transgenic lines were shown to be stably transformed and originate from different transgenic events. The transgenic lines express theFB_MR5 either driven by the constitutive CaMV 35S promoter and the ocs terminator or by its native promoter and terminator sequences. Phenotyping experiments were performed with Mr5-virulent and Mr5-avirulent strains of Erwinia amylovora, the causal agent of fire blight. Significantly less disease symptoms were detected on transgenic lines after inoculation with two different Mr5-avirulent E. amylovorastrains, while significantly more shoot necrosis was observed after inoculation with the Mr5-virulent mutant strain ZYRKD3_1. The results of these experiments demonstrated the ability of a single gene isolated from the native gene pool of apple to protect a susceptible cultivar from fire blight. Furthermore, this gene is confirmed to be the resistance determinant of Mr5 as the transformed lines undergo the same gene-for-gene interaction in the host–pathogen relationship Mr5–E. amylovora.

more...
No comment yet.
Rescooped by Jean-Pierre Zryd from Plant Biology Teaching Resources (Higher Education)
Scoop.it!

Nature: miRNAs trigger widespread epigenetically activated siRNAs from transposons in Arabidopsis

Nature: miRNAs trigger widespread epigenetically activated siRNAs from transposons in Arabidopsis | plant cell genetics | Scoop.it

"Thus miRNA-directed epigenetically activated’ small interfering RNAs (easiRNA) biogenesis is a latent mechanism that specifically targets transposon transcripts, but only when they are epigenetically reactivated during reprogramming of the germ line. This ancient recognition mechanism may have been retained both by transposons to evade long-term heterochromatic silencing and by their hosts for genome defence.


Via Mary Williams
more...
Scooped by Jean-Pierre Zryd
Scoop.it!

Plants Engineered To Produce Insect Perfume Could Act As Pesticides - Gizmodo

Plants Engineered To Produce Insect Perfume Could Act As Pesticides - Gizmodo | plant cell genetics | Scoop.it
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...
more...
No comment yet.
Scooped by Jean-Pierre Zryd
Scoop.it!

Antioxidant activity and total phenolic content of different varieties of Portulaca grandiflora | Lim | International Journal of Phytopharmacy

Antioxidant activity and total phenolic content of different varieties of Portulaca grandiflora | Lim | International Journal of Phytopharmacy | plant cell genetics | Scoop.it

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.

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

Water Filtration Using Plant Xylem

Water Filtration Using Plant Xylem | plant cell genetics | Scoop.it

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.

more...
No comment yet.