Author Archives: fmartin

A new book on Truffles

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truffes

Cet ouvrage est le fruit de près de quarante années de recherches sur les truffes. Il aborde le genre Tuber dans son ensemble. Il traite donc des truffes du monde, Europe, Asie et Amérique du Nord. Il décrit les différentes espèces, donne les caractères essentiels de leur écologie et traite ensuite de la paléogéographie et des relations existant entre les espèces des différents continents. Les différents aspects de la biologie du genre Tuber sont ensuite abordés : état symbiotique, génome, « brûlés », cycle sexué, nutrition carbonée et azotée, métabolisme secondaire, bactéries associées. Sont ensuite traitées les principales espèces comestibles et leur état de domestication dans une perspective historique. L’ouvrage intègre les nouvelles connaissances dans les itinéraires techniques des différents types de trufficulture en prenant en compte les progrès réalisés à la fois en Europe et en Australie. En annexe sont abordés des aspects plus techniques : mycorhization contrôlée, matière organique, eau, conduite de l’irrigation, changements climatiques, arômes artificiels. Ce livre est destiné à tous ceux qui s’intéressent aux truffes, scientifiques, ingénieurs et techniciens, trufficulteurs ou amateurs.

Dynamics of responses to canopy opening in beech trees

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Ph.D. defense

Estelle Noyer “Réponses des perches de hêtre (Fagus sylvativa L.) à l’ouverture de la canopée : approche multidisciplinaire et multi-échelle.”

Friday 12 May at 9.30 am at AgroParisTech-Nancy (Amphithéâtre A).

Abstract: Opening of the canopy exhibits advantages (resources availability) but also new constraints (wind, higher evaporative demand). Rather well documented in saplings, response dynamics to canopy opening is less known in large trees. The thesis aims to identify the dynamics of responses to canopy opening in beech trees suppressed during long periods. Adopted approach is multi-disciplinary and multi-scale, based on a retrospective analysis of axial and radial growth, anatomy and biomechanical traits. For suppressed trees, the competition for light results in preferential allocation of biomass to axial growth in comparison with radial growth resulting in trees with high slenderness. Moreover, one third of suppressed trees are sagging. After the release, high slenderness presents a biomechanical risk: 15 from 36 trees are broken by the wind two years after the release. To increase their safety against the wind-break, trees reduce their axial growth during four years after the release and boost their radial growth reaching a stabilisation plateau after two years likely due to the size and resources limitations. Trees with lean angle higher than 6° up-right after the release. The tree ring hydraulic conductivity increases and stabilises after two year also. The dynamics of responses to canopy opening are therefore clearly trait dependent. Moreover, integrative approach highlighted the importance of size in the responses to canopy opening: while saplings adjust both wood tissue properties and tree geometry, large trees rely only on geometry adjustments.

Key-words : Fagus sylvatica, growth, biomechanics, anatomy, canopy opening, wood.

Symposium Regulation Redox regulation: Historical background and future developments

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Faculté des sciences, Amphitheater 8, Vandoeuvre-lès-Nancy, Université de Lorraine

March 29-31, 2017

Redox regulation referred to as post-translational modifications affecting protein cysteine residues is of great importance for many biological processes. A milestone was the discovery in the 70s that photosynthesis is regulated at several entry points by such modifications. However, over the last decade, it has become obvious in all organisms that additional cellular functions and signaling pathways are controlled by redox changes, some of these being relevant for human health or microbial development and virulence. This redox biology symposium is the third of a series initiated in 2013 in Kaiserslautern followed by a second edition in 2015 already in Nancy. This edition will deal with redox regulation in eukaryote and bacterial systems with emphasis on plants as it is organized in the honor of Pr Jean Pierre Jacquot, who has made pioneering discoveries in this field and will officially retire in 2017.