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Accueil du site > Annuaire > DERR Julien > M2 internship 2013-2014 : Morphogenetic motions of plants : posture regulation in Averrhoa Carambola .

M2 internship 2013-2014 : Morphogenetic motions of plants : posture regulation in Averrhoa Carambola

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Plants offer an excellent example of the beauty of patterns that emerge in nature. We take for granted their regularity and simplicity. However, it has been observed that most plants have a considerably enhanced dynamics during their growth. We call these : ``morphogenetic motions’’ as they are linked to the morphogenesis of the plant. Plant growth is generally caused by the inflation of plant tissues ; more specifically, by a disequilibrium between turgor pressure and the rheology of the cells. Spatial variation of these two parameters causes "differential growth", which can lead to plant motions.

One particular point of interest is the regulation mechanisms in the development of the leaves, and their associated motions. In this internship, we propose to study the particular case of Averrhoa Carambola, which manages to unroll its leave at a constant angle (see a profile view on the left), perfectly regulated while performing a swinging motion called ``circumnutation’’ (see a top view of the leaf on the right). Gravity seems to be here a key parameter, but this aspect is still controversial.

We propose to observe quantitatively the growth of the leaf both in natural conditions, and in pseudo-zero-gravity. Experimentally, we’ll use an existing rotating device called ``clinostat’’ which can simulate zero gravity as well as the use of a time lapse imaging technic to record the motions. Data analysis will imply image analysis and image correlation technics. Finally, we plan to do phenomenological modeling of the growth of the leaf.

Contact : Julien Derr (julien.derrATuniv-paris-diderot.fr), Stéphane Douady

Mots-clés

Dynamique des Systèmes Hors Équilibre, DERR Julien, DOUADY Stéphane, Proposition de stage ou de thèse, Ancienne proposition


Contact : Published on / Publié le 23 septembre 2010