plant cell genetics
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Anti-GMO study is appropriately dismissed as biased, poorly ...

Anti-GMO study is appropriately dismissed as biased, poorly ... | plant cell genetics | Scoop.it
They've been known to sue farmers for reseeding after their crops have cross-polinated non-GMO fields. But these concerns are separate from health risks of a transgenic plant which I find to be vanishingly small.
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Frequent paramutation-like features of natural epialleles in tomato

Freakish and rare or the tip of the iceberg? Both phrases have been used to refer to paramutation, an epigenetic drive that contravenes Mendel's first law of segregation. Although its underlying mechanisms are beginning to unravel, its understanding relies only on a few examples that may involve transgenes or artificially generated epialleles. By using DNA methylation of introgression lines as an indication of past paramutation, we reveal that the paramutation-like properties of the H06 locus in hybrids of Solanum lycopersicum and a range of tomato relatives and cultivars depend on the timing of sRNA production and conform to an RNA-directed mechanism. In addition, by scanning the methylomes of tomato introgression lines for shared regions of differential methylation that are absent in the S. lycopersicum parent, we identify thousands of candidate regions for paramutation-like behaviour. The methylation patterns for a subset of these regions segregate with non Mendelian ratios, consistent with secondary paramutation-like interactions to variable extents depending on the locus. Together these results demonstrate that paramutation-like epigenetic interactions are common for natural epialleles in tomato, but vary in timing and penetrance.

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Subcellular Localization of a Plant Catalase-Phenol Oxidase, AcCATPO, from Amaranthus and Identification of a Non-canonical Peroxisome Targeting Signal

Subcellular Localization of a Plant Catalase-Phenol Oxidase, AcCATPO, from Amaranthus and Identification of a Non-canonical Peroxisome Targeting Signal | plant cell genetics | Scoop.it
AcCATPO is a plant catalase-phenol oxidase recently identified from red amaranth. Its physiological function remains unexplored. As the starting step of functional analysis, here we report its subcellular localization and a non-canonical targeting signal. Commonly used bioinformatics programs predicted a peroxisomal localization for AcCATPO, but failed in identification of canonical peroxisomal targeting signals (PTS). The C-terminal GFP tagging led the fusion protein AcCATPO-GFP to the cytosol and the nucleus, but N-terminal tagging directed the GFP-AcCATPO to peroxisomes and nuclei, in transgenic tobacco. Deleting the tripeptide (PTM) at the extreme C-terminus almost ruled out the peroxisomal localization of GFP-AcCATPOΔ3, and removing the C-terminal decapeptide completely excluded peroxisomes as the residence of GFP-AcCATPOΔ10. Furthermore, this decapeptide as a targeting signal could import GFP-10aa to the peroxisome exclusively. Taken together, these results demonstrate that AcCATPO is localized to the peroxisome and the nucleus, and its peroxisomal localization is attributed to a non-canonical PTS1, the C-terminal decapeptide which contains an internal SRL motif and a conserved tripeptide P-S/T-I/M at the extreme of C-terminus. This work may further the study as to the physiological function of AcCATPO, especially clarify its involvement in betalain biosynthesis, and provide a clue to elucidate more non-canonic PTS.
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Phototropin perceives temperature based on the lifetime of its photoactivated state

Phototropin perceives temperature based on the lifetime of its photoactivated state | plant cell genetics | Scoop.it
Living organisms perceive temperature using thermosensory molecules. In this study, we found that phototropin, a blue-light photoreceptor, perceives temperature via a mechanism based on the photoactivated chromophore’s lifetime to induce appropriate chloroplast positioning in plants. Our findings reveal that the chromophore of phototropin directs chloroplast positioning to optimize photosynthesis in plants by (i) sensing blue light and (ii) sensing temperature via a temperature-dependent lifetime mechanism. Because many photoreceptors in a range of organisms contain phtoactivatable chromophores with a thermodependent lifetime, the present study suggests that a common molecular principle underlies biological perception of temperature.
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Glutamate receptor-like channels are essential for chemotaxis and reproduction in mosses

Glutamate receptors are well characterized channels that mediate cell-to-cell communication during neurotransmission in animals. Nevertheless, information regarding their functional role in organisms without nervous systems is still limited. In plants, Glutamate Receptor-like (GLR) genes have been implicated in defence against pathogens, reproduction, control of stomata aperture and light signal transduction1–5. However, the numerous GLR genes present in angiosperm genomes (20 to 70)6 has prevented the observation of strong phenotypes in loss-of-function mutants. Here, we show that in the moss Physcomitrella patens, a basal land plant, mutation of GLR genes cause sperm failure in targeting the female reproductive organs. In addition, we show that GLR genes encode non-selective Ca2+ permeable channels that can regulate cytoplasmic Ca2+ and are needed to induce the expression of a BELL1-like transcription factor essential for zygote development. Our work reveals novel functions for GLRs in sperm chemotaxis and transcriptional regulation. Sperm chemotaxis is essential for fertilization in both animals and early land plants like bryophytes and pteridophytes. Therefore, our results are suggestive that ionotropic glutamate receptors may have been conserved throughout plant evolution to mediate cell-to-cell communication during sexual reproduction.
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Exposure to Farm Animals and Risk of Lung Cancer in the AGRICAN Cohort | American Journal of Epidemiology | Oxford Academic

Exposure to Farm Animals and Risk of Lung Cancer in the AGRICAN Cohort | American Journal of Epidemiology | Oxford Academic | plant cell genetics | Scoop.it
Epidemiologic studies have found lower risks of lung cancer in farmers. However, little is known about the types of agricultural activities concerned. In the Agriculture and Cancer cohort, we assessed the relationship between animal farming and lung cancer by investigating the types of animals, tasks, and timing of exposure. Analyses included 170,834 participants from the Agriculture and Cancer (AGRICAN) cohort in France. Incident lung cancers were identified through linkage with cancer registries from enrollment (2005–2007) to 2011. A Cox model, adjusting for pack-years of cigarette smoking, was used to calculate hazard ratios and 95% confidence intervals. Lung cancer risk was inversely related to duration of exposure to cattle (≥40 years: hazard ratio = 0.60, 95% confidence interval: 0.41, 0.89; P for trend < 0.01) and to horse farming (≥20 years: hazard ratio = 0.64, 95% confidence interval: 0.35, 1.17; P for trend = 0.09), especially for adenocarcinomas, but not with poultry or pig farming. More pronounced decreased risks were reported among individuals who had cared for animals, undertaken milking, and who had been exposed to cattle in infancy. Our study provides strong evidence of an inverse association between lung cancer and cattle and horse farming. Further research is warranted to identify the etiologic protective agents and biological mechanisms.
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Synthetic Botany

Plants are attractive platforms for synthetic biology and metabolic engineering. Plants’ modular and plastic body plans, capacity for photosynthesis, extensive secondary metabolism, and agronomic systems for large-scale production make them ideal targets for genetic reprogramming. However, efforts in this area have been constrained by slow growth, long life cycles, the requirement for specialized facilities, a paucity of efficient tools for genetic manipulation, and the complexity of multicellularity. There is a need for better experimental and theoretical frameworks to understand the way genetic networks, cellular populations, and tissue-wide physical processes interact at different scales. We highlight new approaches to the DNA-based manipulation of plants and the use of advanced quantitative imaging techniques in simple plant models such as Marchantia polymorpha. These offer the prospects of improved understanding of plant dynamics and new approaches to rational engineering of plant traits.

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Non-model model organisms

Non-model model organisms | plant cell genetics | Scoop.it
Model organisms are widely used in research as accessible and convenient systems to study a particular area or question in biology. Traditionally only a handful of organisms have been widely studied, but modern research tools are enabling researchers to extend the set of model organisms to include less-studied and more unusual systems. This Forum highlights a range of 'non-model model organisms' as emerging systems for tackling questions across the whole spectrum of biology (and beyond), the opportunities and challenges, and the outlook for the future.
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Genetically modified sugarcane developed by CTC in Brazil is approved at CTNBio - Unica (2017) 

The new variety is resistant to sugarcane borer, the main pest that affects the crops in Brazil, generating losses that reach R$ 5 billion per year. 


The ... CTNBio (National Biosafety Technical Commission) has approved the commercial use of the first genetically-modified sugarcane (Bt Sugarcane) developed by the Brazilian sugarcane breeding and technology company... CTC. The Bt Sugarcane variety was submitted to CTNBio, which considered the safety of the biotechnology-derived variety for the environment and human and animal health. This is the first genetically-modified sugarcane approved for marketing in the world.

The new variety, CTC 20 BT, is resistant to crop damage caused by the main sugarcane pest in Brazil, the sugarcane borer. According to a survey carried out by agricultural experts, damage caused by the sugarcane borer results in approximately R$ 5 billion per year, due to losses in sugarcane yield and quality, lower grower insecticide use and costs, and impacts on processors of sugar and ethanol. The helpful Bt gene (Bacillus thuringiensis), found in CTC 20 BT, has been used widely in both Brazilian and global agriculture for over 20 years in biotechnology-derived crops like soybean, maize, cotton, among others. 


“The Bt Sugarcane approval by CTNBio is a great achievement by CTC and the national sugar-ethanol sector”... In the next years, we plan to expand the portfolio of varieties resistant to the borer, adapted to each of the producing regions of Brazil. Further, CTC plans to develop other varieties that are resistant to other insect pests and also tolerant to herbicides... in addition to the economic gains from CTC 20 BT, producers can both simplify their logistics and improve their operation’s environmental management.”

The extensive scientific dossier, which evaluated the genetically-modified sugarcane (GM), was submitted to CTNBio at the end of 2015 for the assessment of health and environmental safety using internationally-accepted standards. Processing studies proved that the sugar and ethanol obtained from the new variety are identical to those products derived from conventional sugarcane. Studies additionally showed that both the Bt gene and protein found in CTC 20 BT sugarcane are completely eliminated from sugarcane derivatives during the manufacturing process. Further, environmental studies did not find any negative effects on soil composition, sugarcane biodegradability, or insect populations, with the exception of the target pests (mainly the borer)... 

CTC will work closely with producers, starting with CTC 20 BT seedling distribution and followed by closely-monitored field planting... “The seedling propagation process will proceed like any conventional new variety introduction, with a planted area growth rate that increases gradually, as new plants are replanted to expand cultivated area and not used in sugar production. This process is aligned with the schedule for obtaining international approvals for the sugar produced from the GM sugarcane”... 


http://english.unica.com.br/news/16900437920334804993/genetically-modified-sugarcane-developed-by-ctc-in-brazil-is-approved-at-ctnbio



Via Alexander J. Stein
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Low Rate of Somatic Mutations in a Long-Lived Oak Tree (L'Arbre de Napoléon UNIL)

Low Rate of Somatic Mutations in a Long-Lived Oak Tree (L'Arbre de Napoléon UNIL) | plant cell genetics | Scoop.it


Because plants do not possess a proper germline, deleterious mutations that occur in the soma can be passed to gametes. It has generally been assumed that the large number of somatic cell divisions separating zygote from gamete formation in long-lived plants should lead to many mutations. However, a recent study showed that surprisingly few cell divisions separate apical stem cells from axillary stem cells in annual plants, challenging this view. To test this prediction, we generated and analysed the full genome sequence of two terminal branches of a 234-year-old oak tree and found very few fixed somatic single-nucleotide variants (SNVs), whose sequential appearance in the tree could reliably be traced back along nested sectors of younger branches. Our data indicate that the stem cells of shoot meristems in trees are robustly protected from accumulation of mutations, analogous to the germline in animals.


https://fr.wikipedia.org/wiki/Ch%C3%AAne_de_Napol%C3%A9on

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Cells reprogramming to stem cells inhibit the reprogramming of adjacent cells in the moss Physcomitrella patens

Cells reprogramming to stem cells inhibit the reprogramming of adjacent cells in the moss Physcomitrella patens | plant cell genetics | Scoop.it
Under certain circumstances differentiated cells can be reprogrammed to form stem cells in land plants, but only a portion of the cells reprograms successfully. A long-distance inhibitory signal from reprogrammed cells to surrounding cells has been reported in some ferns. Here we show the existence of anisotropic inhibitory signal to regulate stem cell formation in the moss Physcomitrella patens. When single cells were isolated from a gametophore leaf, over 90% of them were reprogrammed to stem cells with characteristic nuclear expansion. By contrast, when two adjacent cells were isolated, the nuclei of both cells expanded, but successful reprogramming of both cells occurred only in approximately one fifth of the pairs. When three aligned cells were isolated, the reprogramming rate of both edge cells decreased with a living middle cell but did not with a dead middle cell. Furthermore, unequal conversion into stem cells was more prominent in cell pairs aligned parallel to the proximal-distal leaf axis than in those perpendicular to the axis. This study gives an insight into the role of the inhibitory signal in development and evolution as well as the efficient stem cell induction from differentiated cells.
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Cytosolic and Nuclear Co-localization of Betalain Biosynthetic Enzymes in Tobacco Suggests that Betalains Are Synthesized in the Cytoplasm and/or Nucleus of Betalainic Plant Cells | Pla...

Cytosolic and Nuclear Co-localization of Betalain Biosynthetic Enzymes in Tobacco Suggests that Betalains Are Synthesized in the Cytoplasm and/or Nucleus of Betalainic Plant Cells | Pla... | plant cell genetics | Scoop.it
Betalains replace anthocyanins as color pigments in most families of Caryophyllales. Unlike anthocyanins, betalains are derived from tyrosine via three enzymatic steps: hydroxylation of L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA; step 1), and conversion of L-DOPA to betalamic acid (step 2), and to cyclo-DOPA (cDOPA; step 3). The principal enzymes responsible for these reactions have been elucidated at the molecular level, but their subcellular localizations have not been explored; hence, the intracellular compartments wherein betalains are biosynthesized remain unknown. Here, we report on the subcellular localization of these principal enzymes. Bioinformatic predictors and N- and C-terminal GFP tagging in transgenic tobacco, showed that Beta vulgaris CYP76AD1 which mediates both steps 1 and 3, DODA1 that catalyzes step 2, and CYP76AD6 which also mediates step 1, were similarly localized to the cytoplasm and nucleus (although the P450s were also weakly present in the endoplasmic reticulum). These two compartments were also the principal locations of Mirabilis jalapa cDOPA5GT. The cytoplasmic and nuclear co-localization of these key enzymes in tobacco suggests that betalains are biosynthesized in the cytoplasm and/or nucleus of betalain-containing plant cells. Elucidation of the subcellular compartmentation of betalain biosynthesis will facilitate the bioengineering of the betalain biosynthetic pathway in non-betalain-containing plants.
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New alleles of the wheat domestication gene Q reveal multiple roles in growth and reproductive development

New alleles of the wheat domestication gene Q reveal multiple roles in growth and reproductive development | plant cell genetics | Scoop.it
The advantages of free threshing in wheat led to the selection of the domesticated Q allele, which is now present in almost all modern wheat varieties. Q and the pre-domestication allele, q, encode an AP2 transcription factor, with the domesticated allele conferring a free-threshing character and a subcompact (i.e. partially compact) inflorescence (spike). We demonstrate that mutations in the miR172 binding site of the Q gene are sufficient to increase transcript levels via a reduction in miRNA-dependent degradation, consistent with the conclusion that a single nucleotide polymorphism in the miRNA binding site of Q relative to q was essential in defining the modern Q allele. We describe novel gain- and loss-of-function alleles of Q and use these to define new roles for this gene in spike development. Q is required for the suppression of ‘sham ramification’, and increased Q expression can lead to the formation of ectopic florets and spikelets (specialized inflorescence branches that bear florets and grains), resulting in a deviation from the canonical spike and spikelet structures of domesticated wheat.
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Plant biology: An immunity boost combats crop disease : Nature

Plant biology: An immunity boost combats crop disease : Nature | plant cell genetics | Scoop.it
Xu and colleagues provide insight into how features of the 5′ region of the TBF1 mRNA mediate its translational control. In this region, there are two previously identified10 short upstream open reading frames (uORFs), sequences that encode short peptides and precede the start of the open reading frame (ORF) that encodes TBF1. The authors identified another feature of interest in this 5′ region — a short adenine-rich nucleotide sequence located just before the two uORFs (Fig. 1). Adenine is a nucleotide known as a purine, and because purines are often designated by the letter 'R', the authors named this sequence the R-motif. They found that, in the absence of pathogen challenge, the uORFs strongly inhibit the ability of the ribosome protein-synthesis machinery to translate the TBF1-encoding ORF located downstream in the mRNA. The R-motif adds to this translational control. When plants were treated with elf18, the authors found that this repression of TBF1 synthesis was rapidly and transiently reversed.

Via Francis Martin
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Nanobody‐mediated resistance to Grapevine fanleaf virus in plants

Nanobody‐mediated resistance to Grapevine fanleaf virus in plants | plant cell genetics | Scoop.it

Since their discovery, single-domain antigen-binding fragments of camelid-derived heavy chain-only antibodies, also known as Nanobodies (Nbs), have proven to be of outstanding interest as therapeutics against human diseases and pathogens including viruses, but their use against phytopathogens remains limited. Many plant viruses including Grapevine fanleaf virus (GFLV), a nematode-transmitted icosahedral virus and causal agent of fanleaf degenerative disease, have worldwide distribution and huge burden on crop yields representing billions of US dollars of losses annually, yet solutions to combat these viruses are often limited or inefficient. Here we identified a Nb specific to GFLV that confers strong resistance to GFLV upon stable expression in the model plant Nicotiana benthamiana and also in grapevine rootstock, the natural host of the virus. We showed that resistance was effective against a broad range of GFLV isolates independently of the inoculation method including upon nematode transmission but not against its close relative, Arabis mosaic virus. We also demonstrated that virus neutralization occurs at an early step of the virus life cycle, prior to cell-to-cell movement. Our findings will not only be instrumental to confer resistance to GFLV in grapevine but more generally they pave the way for the generation of novel antiviral strategies in plants based on Nbs.

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Engineered gray mold resistance, antioxidant capacity, and pigmentation in betalain-producing crops and ornamentals

Engineered gray mold resistance, antioxidant capacity, and pigmentation in betalain-producing crops and ornamentals | plant cell genetics | Scoop.it
In plants, three major classes of pigments are generally responsible for colors seen in fruits and flowers: anthocyanins, carotenoids, and betalains. Betalains are red-violet and yellow plant pigments that have been reported to possess strong antioxidant and health-promoting properties, including anticancer, antiinflammatory, and antidiabetic activity. Here, heterologous betalain production was achieved for the first time in three major food crops: tomato, potato, and eggplant. Remarkably, betalain production in tobacco resulted in significantly enhanced resistance toward gray mold (Botrytis cinerea), a plant pathogen responsible for major crop losses. Considering the significant characteristics of these molecules, heterologous betalain production now offers exciting opportunities for creating new value for consumers, producers, and suppliers of food crops and ornamental plants.
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Actin fringes of polar cell growth

Actin fringes of polar cell growth | plant cell genetics | Scoop.it
The eukaryotic actin cytoskeleton is a highly dynamic framework that is involved in many biological processes, such as cell growth, division, morphology, and motility. G-actin polymerizes into microfilaments that associate into bundles, patches, and networks, which, in turn, organize into higher order structures that are fundamental for the course of important physiological events. Actin rings are an example for such higher order actin entities, but this term represents an actually diverse set of subcellular structures that are involved in various processes. This review especially sheds light on a crucial type of non-constricting ring-like actin networks, and categorizes them under the term ‘actin fringe’. These ‘actin fringes’ are visualized as highly dynamic and yet steady structures in the tip of various polarized growing cells. The present comprehensive overview compares the actin fringe characteristics of rapidly elongating pollen tubes with several related actin arrays in other cell types of diverse species. The current state of knowledge about various actin fringe functions is summarized, and the key role of this structure in the polar growth process is discussed.
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Cancer incidence in the AGRICAN cohort study (2005–2011)



Cancer incidence was not different between the cohort and the general population.


A lower incidence was observed for tobacco-related and female breast cancers.


Prostate, NHL, especially MM and skin melanoma were increased in the cohort.


Increase in risk was greater among male farmworkers for prostate and lip cancers.


Skin melanoma risk in women was greater among pesticide users on crops.
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Plant glandular trichomes: natural cell factories of high biotechnological interest

Plant glandular trichomes: natural cell factories of high biotechnological interest | plant cell genetics | Scoop.it
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Via Loïc Lepiniec
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A transgenic strategy for controlling plant bugs (Adelphocoris suturalis) through expression of double‐stranded RNA homologous to fatty acyl‐coenzyme A reductase in cotton

A transgenic strategy for controlling plant bugs (Adelphocoris suturalis) through expression of double‐stranded RNA homologous to fatty acyl‐coenzyme A reductase in cotton | plant cell genetics | Scoop.it
Plant bugs (Miridae species), which are sap-sucking insects, have emerged as major pests of cotton in China. Most Miridae species are not sensitive to commercial Bacillus thuringiensis (Bt) cotton, resulting in significant economic losses and an increased application of insecticide, which eventually may compromise the future of Bt cotton.
We demonstrate that FATTY ACYL-COA REDUCTASE (AsFAR) plays an essential role in the reproduction of the bug Adelphocoris suturalis. Down-regulation of AsFAR expression by injection of double-stranded RNA suppresses ovarian development and female fertility, resulting in females producing few viable offspring.
To determine the viability of an RNA interference approach to limit FAR expression and reproductive ability in A. suturalis, a dsRNA targeting the AsFAR gene (dsAsFAR) of A. suturalis was expressed in transgenic cotton plants. AsFAR transcription levels were significantly downregulated in A. suturalis feeding on the transgenic plants. In contained field trials, the transgenic cotton lines significantly suppressed the development of A. suturalis populations and were resistant to damage caused by plant bug infestation.
These results suggest a new strategy for the management of plant bug pests of cotton.
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Nicotine in floral nectar pharmacologically influences bumblebee learning of floral features

Nicotine in floral nectar pharmacologically influences bumblebee learning of floral features | plant cell genetics | Scoop.it

Many plants defend themselves against herbivores by chemical deterrents in their tissues and the presence of such substances in floral nectar means that pollinators often encounter them when foraging. The effect of such substances on the foraging behaviour of pollinators is poorly understood. Using artificial flowers in tightly-controlled laboratory settings, we examined the effects of the alkaloid nicotine on bumblebee foraging performance. We found that bumblebees confronted simultaneously with two equally rewarded nicotine-containing and nicotine-free flower types are deterred only by unnaturally high nicotine concentrations. This deterrence disappears or even turns into attraction at lower nectar-relevant concentrations. The alkaloid has profound effects on learning in a dose-dependent manner. At a high natural dose, bees learn the colour of a nicotine-containing flower type more swiftly than a flower type with the same caloric value but without nicotine. Furthermore, after experiencing flowers containing nicotine in any tested concentration, increasing numbers of bumblebees stay more faithful to these flowers, even if they become a suboptimal choice in terms of reward. These results demonstrate that alkaloids enhance pollinator flower constancy, opening new perspectives in co-evolutionary process between plants and pollinators.

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Evolutionary forces affecting synonymous variations in plant genomes

Evolutionary forces affecting synonymous variations in plant genomes | plant cell genetics | Scoop.it
Author summary In protein coding genes, base composition strongly varies within and among plant genomes, especially at positions where changes do not alter the coded protein (synonymous variations). Some species, such as the model plant Arabidopsis thaliana, are relatively GC-poor and homogeneous while others, such as grasses, are highly heterogeneous and GC-rich. The causes of these variations are still debated: are they mainly due to selective or neutral processes? Answering to this question is important to correctly infer whether variations in base composition may have functional roles or not. We extended a population genetics method to jointly estimate the different forces that may affect synonymous variations and applied it to genomic datasets in 11 flowering plant species. We found that GC-biased gene conversion, a neutral process associated with recombination that mimics selection by favouring G and C bases, is a widespread and stronger process than selection and that it could explain the large variation in base composition observed in plant genomes. Our results bear implications for analysing plant genomes and for correctly interpreting what could be functional or not.
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Advances in the MYB–bHLH–WD Repeat (MBW) Pigment Regulatory Model: Addition of a WRKY Factor and Co-option of an Anthocyanin MYB for Betalain Regulation | Plant and Cell Physiology | Oxford Academic

Advances in the MYB–bHLH–WD Repeat (MBW) Pigment Regulatory Model: Addition of a WRKY Factor and Co-option of an Anthocyanin MYB for Betalain Regulation | Plant and Cell Physiology | Oxford Academic | plant cell genetics | Scoop.it
Flavonoids are secondary metabolites derived from the general phenylpropanoid pathway and are widespread throughout the plant kingdom. The functions of flavonoids are diverse, including defense against phytopathogens, protection against UV light damage and oxidative stress, regulation of auxin transport and allelopathy. One of the most conspicuous functions of flavonoids has long attracted the attention of pollinators and scientist alike: the vivid shades of red, pink, orange, blue and purple on display in the flowers of angiosperms. Thus, flavonoid pigments have perhaps been the most intensely studied phenylpropanoids. From Mendel to McClintock and up to the present, studies centered on flavonoid pigments have resulted in some of the most important scientific discoveries of the last 150 years, including the first examples of transcriptional regulation in plants. Here we focus on the highly conserved MYB–bHLH–WD repeat (MBW) transcriptional complex model for the regulation of the flavonoid pigment pathway. We will survey the history of the MBW model spanning the last three decades, highlighting the major findings that have contributed to our current understanding. In particular, recent discoveries regarding WRKY protein control of the flavonoid pigment pathway and its relationship to the MBW complex will be emphasized. In addition, we will discuss recent findings about the regulation of the beet betalain pigment pathway, and how a MYB member of the MBW complex was co-opted to regulate this chemically unrelated but functionally equivalent pathway.
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Towards mastering CRISPR-induced gene knock-in in plants: Survey of key features and focus on the model Physcomitrella patens

Towards mastering CRISPR-induced gene knock-in in plants: Survey of key features and focus on the model Physcomitrella patens | plant cell genetics | Scoop.it
Beyond its predominant role in human and animal therapy, the CRISPR-Cas9 system has also become an essential tool for plant research and plant breeding. Agronomic applications rely on the mastery of gene inactivation and gene modification. However, if the knock-out of genes by non-homologous end-joining (NHEJ)-mediated repair of the targeted double-strand breaks (DSBs) induced by the CRISPR-Cas9 system is rather well mastered, the knock-in of genes by homology-driven repair or end-joining remains difficult to perform efficiently in higher plants. In this review, we describe the different approaches that can be tested to improve the efficiency of CRISPR–induced gene modification in plants, which include the use of optimal transformation and regeneration protocols, the design of appropriate guide RNAs and donor templates and the choice of nucleases and means of delivery. We also present what can be done to orient DNA repair pathways in the target cells, and we show how the moss Physcomitrella patens can be used as a model plant to better understand what DNA repair mechanisms are involved, and how this knowledge could eventually be used to define more performant strategies of CRISPR-induced gene knock-in.
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CRISPR, microbes and more are joining the war against crop killers

CRISPR, microbes and more are joining the war against crop killers | plant cell genetics | Scoop.it

Agricultural scientists look beyond synthetic chemistry to battle pesticide resistance.


Resistance to conventional pesticides — among insects, weeds or microbial pathogens — is common on farms worldwide. CropLife International, an industry association based in Brussels, supports efforts that have counted 586 arthropod species, 235 fungi and 252 weeds with resistance to at least one synthetic pesticide (see 'The rise of resistance'). And that's just the cases that scientists have formally identified and recorded.

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Newton's journal reveals seeds of plant biology

Newton's journal reveals seeds of plant biology | plant cell genetics | Scoop.it
Sir Isaac Newton's interest in botany extended well beyond the fabled apple falling from a tree - he also appears to have understood how water moves from roots to leaves over 200 years before botanists did.

Via Mariaschnee
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