A new scenario for gravity detection in plants: the position sensor hypothesis

Olivier Pouliquen (1) , Yoël Forterre (1) , Antoine Bérut (1) , Hugo Chauvet (1, 2) , François Bizet (2) , Valérie Legue (2) , Bruno Moulia (2)

1 IUSTI - Institut universitaire des systèmes thermiques industriels
2 PIAF - Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant

The detection of gravity plays a fundamental role during the growth and evolution of plants. Although progress has been made in our understanding of the molecular, cellular and physical mechanisms involved in the gravity detection, a coherent scenario consistent with all the observations is still lacking. In this perspective paper we discuss recent experiments showing that the response to inclination of shoots is independent of the gravity intensity, meaning that the gravity sensor detects an inclination and not a force. This result questions some of the commonly accepted hypotheses and leads to propose a new "position sensor hypothesis". The implications of this new scenario are discussed in the light of different observations available in the literature.

Mots clés: gravitropism; sensing; starch-deficient mutants; amyloplast; sedimentation; arabidopsis-thaliana; shoot gravitropism; columella; inflorescence stems; actin cytoskeleton; root gravitropism; cress; roots

Mots clés: plants; lateral auxin gradient; cells

Domaines: Biophysique [physics.bio-ph]; Biologie végétale

Olivier Pouliquen, Yoël Forterre, Antoine Bérut, Hugo Chauvet, François Bizet, et al.. A new scenario for gravity detection in plants: the position sensor hypothesis. Physical Biology, 2017, 14 (3), pp.035005. ⟨10.1088/1478-3975/aa6876⟩. ⟨hal-01425608v3⟩