The issues of apricot (Prunus Armeniaca L.) Micropropagation

The effect of four modified mediums for apricot multiplication was observed in this study. A total number of 1864 single nodes of 20 Prunus armeniaca L.varieties were established. Explants surface was disinfected with 0.2 % mercuric chloride for 5 minutes. MS (1962) medium with 0.5 mg.l-1 BA, 0.01 mg.l-1 NAA and 0.5 mg.l-1 GA3 was used as a medium for primary culture. 'Velkopavlovická', 'Bergeron', genotype 1128 and genotype LE 2927 Š9 were successfully transferred to aseptic conditions and multiplied. Modified MS medium (1962), DKW/Juglans medium, Quoirin, Lepoivre (1977) medium and Marino et al. (1991) medium were used for multiplication. Modified MS medium and modified DKW/Juglans medium were not suitable for apricot multiplication at all and explants did not grow. The best results were observed in the case of Quoirin, Lepoivre (1977) medium with 0.4 mg. l-1 BA and 0.01 mg.l-1 NAA. Young plants multiplied well, were fresh and vital and no damage was observed. The highest number of new shoots was observed in the case of Marino et al. (1991) medium. The average growth of new shoots after the last passaging was 600 %, rate 7.33 (Velkopavlovická); 566 %, rate 7.0 (Bergeron); 475 %, rate 6.25 (1128) and 483 %, rate 6.33 (LE 2927 Š9)). However, new shoots in clusters were too dense and stunted and this medium is not recommended for apricot multiplication.O

La médiation humaniste, pour ‘faire société’ dans la prise en charge des différends

This paper is the work of a collective, and contains multidisciplinary reflexions on a humanistic practice of mediation that was pioneered in France in 1984, and refined over 30 years of practical experience and thousands of completed mediations. This kind of mediation focuses its efforts less on the specific area of dispute, and more on the transformation of human and social relationships, thereby justifying the qualifier ‘humanistic’. The exchanges established between the mediants, made possible and facilitated by the mediator, have the core objective of rebuilding a lasting and peaceable relationship.Humanistic mediation is shown to be a tool for personal, ontological transformation – a way of supporting the deep aspirations and values which everyone needs in order to live. In social interaction it enables common ground (‘commons’) to emerge which forms the basis of a new mode of sharing; it introduces a process that is humanizing and mutually nurturing while still respecting differences. Humanistic mediation is rooted in the trans-modern beginnings of our ongoing societal transformation. By reintroducing a sense of existential solidarity which is founded more on sharing than on exchange, it offers itself as an educational tool for peace, using a civilizing pedagogy to create a humanism for our times.The process is laid out in three sequential phases, which take into account the emotions of the mediants. With often spectacular results, the process leads to a pivotal moment that allows the energy of the conflict to be redirected. The role and attitude of the mediator are precisely defined. The relationship between mediation and institutions such as justice and education is discussed. Humanistic mediation takes its place in the evolution of a justice that both repairs and restores.Cet article est la réflexion pluridisciplinaire d’un collectif sur une pratique humaniste de la médiation, introduite de façon pionnière en 1984 et affinée au cours de 30 ans d’expérience et de milliers de médiations réalisées. Ce type de médiation concentre ses efforts moins sur le différend que sur la transformation des rapports humains et sociaux, justifiant ainsi le qualificatif humaniste. Les échanges instaurés entre les médiants, rendus possibles et facilités par le médiateur, ont pour objectif essentiel de reconstruire une relation pacifiée et durable.La médiation humaniste se révèle un outil ontologique de transformation personnelle prenant appui sur les aspirations profondes et les valeurs dont chacun a besoin pour vivre. Socialement, elle permet l’émergence de communs sur lesquels fonder un nouveau mode de partage, introduisant un processus de fécondation mutuelle et d’humanisation réciproque, dans le respect des différences. La médiation humaniste s’inscrit dans les prémices trans-modernes de la transformation sociétale en cours. Réintroduisant le sens d’une solidarité existentielle, fondée plus sur le partage que sur l’échange, elle se présente comme un outil d’éducation à la paix, pédagogique et civilisateur, pour un humanisme de notre temps.Le déroulement en est explicité en trois phases successives prenant en compte les émotions des médiants et aboutissant à un retournement souvent spectaculaire qui permet de réorienter l’énergie du conflit. Le rôle et la posture du médiateur sont précisés.Le rapport aux institutions Justice et Education est discuté. La médiation humaniste s’inscrit dans une démarche de justice réparatrice et restauratrice

CRISPR-Cas9 <i>In Situ</i> engineering of subtilisin E in <i>Bacillus subtilis</i>

<div><p>CRISPR-Cas systems have become widely used across all fields of biology as a genome engineering tool. With its recent demonstration in the Gram positive industrial workhorse <i>Bacillus subtilis</i>, this tool has become an attractive option for rapid, markerless strain engineering of industrial production hosts. Previously described strategies for CRISPR-Cas9 genome editing in <i>B</i>. <i>subtilis</i> have involved chromosomal integrations of Cas9 and single guide RNA expression cassettes, or construction of large plasmids for simultaneous transformation of both single guide RNA and donor DNA. Here we use a flexible, co-transformation approach where the single guide RNA is inserted in a plasmid for Cas9 co-expression, and the donor DNA is supplied as a linear PCR product observing an editing efficiency of 76%. This allowed multiple, rapid rounds of <i>in situ</i> editing of the subtilisin E gene to incorporate a salt bridge triad present in the <i>Bacillus clausii</i> thermotolerant homolog, M-protease. A novel subtilisin E variant was obtained with increased thermotolerance and activity.</p></div

Adenosyl Radical: Reagent and Catalyst in Enzyme Reactions

Adenosine is undoubtedly an ancient biological molecule that is a component of many enzyme cofactors: ATP, FADH, NAD(P)H, and coenzyme A, to name but a few, and, of course, of RNA. Here we present an overview of the role of adenosine in its most reactive form: as an organic radical formed either by homolytic cleavage of adenosylcobalamin (coenzyme B 12 , AdoCbl) or by single-electron reduction of S -adenosylmethionine (AdoMet) complexed to an iron–sulfur cluster. Although many of the enzymes we discuss are newly discovered, adenosine's role as a radical cofactor most likely arose very early in evolution, before the advent of photosynthesis and the production of molecular oxygen, which rapidly inactivates many radical enzymes. AdoCbl-dependent enzymes appear to be confined to a rather narrow repertoire of rearrangement reactions involving 1,2-hydrogen atom migrations; nevertheless, mechanistic insights gained from studying these enzymes have proved extremely valuable in understanding how enzymes generate and control highly reactive free radical intermediates. In contrast, there has been a recent explosion in the number of radical-AdoMet enzymes discovered that catalyze a remarkably wide range of chemically challenging reactions; here there is much still to learn about their mechanisms. Although all the radical-AdoMet enzymes so far characterized come from anaerobically growing microbes and are very oxygen sensitive, there is tantalizing evidence that some of these enzymes might be active in aerobic organisms including humans.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69165/1/604_ftp.pd

Utilisation de la transgénose pour l'obtention de pruniers et d'abricotiers exprimant le gène de la protéine capside du plum pox potyvirus

National audienc

Use of transgenic techniques to develop resistance to plum pox virus in prunus species

International audienc

Cloning, expression, characterisation and mutational analysis of l-aspartate oxidase from Pseudomonas putida

L-Amino acid oxidases (LAAOs) are useful catalysts for the deracemisation of racemic amino acid sub-strates when combined with abiotic reductants. The gene nadB encoding the L-aspartate amino acid oxidase from Pseudomonas putida (PpLASPO) has been cloned and expressed in E. coli. The purified PpLASPO enzyme displayed a K M for l-aspartic acid of 2.26 mM and a k cat = 10.6 s −1 , with lower activity also displayed towards L-asparagine, for which pronounced substrate inhibition was also observed. The pH optimum of the enzyme was recorded at pH 7.4. The enzyme was stable for 60 min at up to 40 • C, but rapid losses in activity were observed at 50 • C. A mutational analysis of the enzyme, based on its sequence homology with the LASPO from E. coli of known structure, appeared to confirm roles in substrate binding or catalysis for residues His244, His351, Arg386 and Arg290 and also for Thr259 and Gln242. The high activity of the enzyme, and its promiscuous acceptance of both L-asparagine and L-glutamate as substrates, if with low activity, suggests that PpLASPO may provide a good model enzyme for evolution studies towards AAOs of altered or improved properties in the future