623,017 research outputs found

    Future breeding for organic and low-input agriculture: integrating values and modern breeding tools for improving robustness

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    Organic production and also the attention for plant breeding for organic agriculture is still increasing in Europe. The question often raised is how much does plant breeding for the organic sector differ from modern plant breeding and does a ban on GMO also include refraining from molecular marker assisted selection (MAS)? In this paper I will first elaborate on the values in organic agriculture and it related systems approach as a central focus in organic agriculture and will then discuss in which way molecular marker assisted selection can be of use for plant breeding for organic and low-input agriculture

    Evolution of an ancient protein function involved in organized multicellularity in animals.

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    To form and maintain organized tissues, multicellular organisms orient their mitotic spindles relative to neighboring cells. A molecular complex scaffolded by the GK protein-interaction domain (GKPID) mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues. Here we illuminate how this complex evolved and commandeered control of spindle orientation from a more ancient mechanism. The complex was assembled through a series of molecular exploitation events, one of which - the evolution of GKPID's capacity to bind the cortical marker protein - can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GKPID. This change revealed and repurposed an ancient molecular surface that previously had a radically different function. We show how the physical simplicity of this binding interface enabled the evolution of a new protein function now essential to the biological complexity of many animals

    Lectin ligands: New insights into their conformations and their dynamic behavior and the discovery of conformer selection by lectins

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    The mysteries of the functions of complex glycoconjugates have enthralled scientists over decades. Theoretical considerations have ascribed an enormous capacity to store information to oligosaccharides, In the interplay with lectins sugar-code words of complex carbohydrate structures can be deciphered. To capitalize on knowledge about this type of molecular recognition for rational marker/drug design, the intimate details of the recognition process must be delineated, To this aim the required approach is garnered from several fields, profiting from advances primarily in X-ray crystallography, nuclear magnetic resonance spectroscopy and computational calculations encompassing molecular mechanics, molecular dynamics and homology modeling. Collectively considered, the results force us to jettison the preconception of a rigid ligand structure. On the contrary, a carbohydrate ligand may move rather freely between two or even more low-energy positions, affording the basis for conformer selection by a lectin. By an exemplary illustration of the interdisciplinary approach including up-to-date refinements in carbohydrate modeling it is underscored why this combination is considered to show promise of fostering innovative strategies in rational marker/drug design

    Molecular Marker-Assisted Selection of Rice Grain Quality on Rice (Oryza Sativa L.) Lines Tolerant to Fe Toxicity Stress

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    The elite rice has been produced, including iron (Fe) tolerant varieties. To get the appropriate rice lines which superior not only Fe tolerant but also have good grain quality needs to be developed selection system, especially in the use of molecular markers. This study was aimed to develop molecular markers for selection the rice grain quality characters of selected rice lines Fe tolerant. A total of 30 selected Fe tolerant rice lines and 5 parents as control lines were used in this research. Characterization of grain quality were quantitatively using the standard. While for genotyping analysis used 19 molecular markers of STS, SSR, Indel and SNP. This study showed that 14 of 19 markers result polymorphic DNA band (DNA markers). Association analysis of genotype and phenotype showed that 10 of 14 markers were significantly (p < 0.05) related to high quality of rice grain. Among four types of markers used in this study, STS was the most widely associated significantly with four characters of rice quality. The phenotyping analysis showed that the physical grain and palatability quality which obtained from the total mean of 30 rice lines tested tend to nearly with the parent\u27s value as controls lines. The most of these lines were included in the group IV of National Rice Grain Quality Standard (SNI). The amylose content (AC) showed that the texture was varied from firm and dry (high AC) to soft and sticky (low AC). The association results showed that there were significant (p ≤ 0.05) markers related with the biosynthesis starch genes, i.e: SBE1, SS1, SSIIa, GPA, PUL and S3cl which contributed on the character of rice palatability. These selected significant markers could be useful for screening of other population with Fe tolerant and/ or other desired morpho-agronomical traits in support of rice breeding program in Indonesia

    Stabilization and precise calibration of a continuous-wave difference frequency spectrometer by use of a simple transfer cavity

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    A novel, simple, and inexpensive calibration scheme for a continuous-wave difference frequency spectrometer is presented, based on the stabilization of an open transfer cavity by locking onto the output of a polarization stabilized HeNe laser. High frequency, acoustic fluctuations of the transfer cavity length are compensated with a piezoelectric transducer mounted mirror, while long term drift in cavity length is controlled by thermal feedback. A single mode Ar+ laser, used with a single mode ring dye laser in the difference frequency generation of 2–4 µm light, is then locked onto a suitable fringe of this stable cavity, achieving a very small long term drift and furthermore reducing the free running Ar+ linewidth to about 1 MHz. The dye laser scan provides tunability in the difference frequency mixing process, and is calibrated by marker fringes with the same stable cavity. Due to the absolute stability of the marker cavity, precise frequency determination of near infrared molecular transitions is achieved via interpolation between these marker fringes. It is shown theoretically that the residual error of this scheme due to the dispersion of air in the transfer cavity is quite small, and experimentally that a frequency precision on the order of 1 MHz per hour is routinely obtained with respect to molecular transitions. Review of Scientific Instruments is copyrighted by The American Institute of Physics

    Modern approaches for breeding high quality apples with durable resistance to scab, powdery mildew and fire blight

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    New methods to allow for more precise selection of tree and fruit characters in breeding programmes were developed in recent years. Marker-assisted selection (MAS) is common practice in the ACW apple breeding programme at Wädenswil. Genetic markers can reduce the number of plants and the time required for evaluation, thus new varieties become commercially available sooner. How can this molecular selection method reasonably be applied in an apple breeding programme? Application of phenotypic and molecular selection techniques in the ACW apple breeding programme and results are presented

    Imaging correlates of molecular signatures in oligodendrogliomas.

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    Molecular subsets of oligodendroglioma behave in biologically distinct ways. Their locations in the brain, rates of growth, and responses to therapy differ with their genotypes. Retrospectively, we inquired whether allelic loss of chromosomal arms 1p and 19q, an early molecular event and favorable prognostic marker in oligodendrogliomas, were reflected in their appearance on magnetic resonance imaging. Loss of 1p and 19q was associated with an indistinct border on T(1) images and mixed intensity signal on T(1) and T(2). Loss of 1p and 19q was also associated with paramagnetic susceptibility effect and with calcification, a common histopathological finding in oligodendrogliomas. These data encourage prospective evaluation of molecular alterations and magnetic resonance imaging characteristics of glial neoplasms

    Natural history of Arabidopsis thaliana and oomycete symbioses

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    Molecular ecology of plant–microbe interactions has immediate significance for filling a gap in knowledge between the laboratory discipline of molecular biology and the largely theoretical discipline of evolutionary ecology. Somewhere in between lies conservation biology, aimed at protection of habitats and the diversity of species housed within them. A seemingly insignificant wildflower called Arabidopsis thaliana has an important contribution to make in this endeavour. It has already transformed botanical research with deepening understanding of molecular processes within the species and across the Plant Kingdom; and has begun to revolutionize plant breeding by providing an invaluable catalogue of gene sequences that can be used to design the most precise molecular markers attainable for marker-assisted selection of valued traits. This review describes how A. thaliana and two of its natural biotrophic parasites could be seminal as a model for exploring the biogeography and molecular ecology of plant–microbe interactions, and specifically, for testing hypotheses proposed from the geographic mosaic theory of co-evolution
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