Salt stress triggers enhanced cycling of Arabidopsis root plasma-membrane aquaporins.

Alexandre Martinière (1, 2) , Xiaojuan Li (3) , John Runions (1) , Jinxing Lin (3) , Christophe Maurel (2) , Doan-Trung Luu (2)

1 School of Life Sciences
2 BPMP - Biochimie et Physiologie Moléculaire des Plantes
3 Key Laboratory of Plant Molecular Physiology

Aquaporins of the plasma membrane intrinsic protein (PIP) subfamily are channels which facilitate the diffusion of water across the plant plasma membrane (PM). Although PIPs have been considered as canonical protein markers of this compartment, their endomembrane trafficking is still not well documented. We recently obtained insights into the constitutive cycling of PIPs in Arabidopsis root cells by means of fluorescence recovery after photobleaching (FRAP). This work also uncovered the behavior of the model isoform AtPIP2;1 in response to NaCl. The present addendum connects these findings to another recent work which describes the dynamic properties of AtPIP2;1 in the PM in normal and salt stress conditions by means of single particle tracking (SPT) and fluorescence correlation spectroscopy (FCS). The results suggest that membrane rafts play an important role in the partitioning of AtPIP2;1 in normal conditions and that clathrin-mediated endocytosis is predominant. In salt stress conditions, the rate of AtPIP2;1 cycling was enhanced and endocytosis was cooperated by a membrane raft-associated salt-induced pathway and a clathrin-dependent pathway.

Mots clés: aquaporin; constitutive cycling; fluorescence correlation spectroscopy; fluorescence recovery after photobleaching; salt stress; single particle tracking

Domaines: Biologie végétale

Alexandre Martinière, Xiaojuan Li, John Runions, Jinxing Lin, Christophe Maurel, et al.. Salt stress triggers enhanced cycling of Arabidopsis root plasma-membrane aquaporins.. Plant Signaling and Behavior, 2012, 7 (4), pp.529-32. ⟨10.4161/psb.19350⟩. ⟨hal-00777032⟩