Group leader: Isabelle Gaillard
Research Director INRAE
membrane transport systems, molecular regulators, potassium, proton, genetic pH probes, climate change, acidity and quality of fruit, translational biology, grape berry, Arabidopsis, grapevine
The main objective of our group is the identification and characterization of molecular players (in priority membrane transport systems) involved in the control of fruit acidity during maturation.
In grapevine, grape acidity is a key factor that determines berry and hence wine quality. The K+ ion, as the major counterion, allows the neutralization of tartaric acid, one of the main organic acids of the grape, and thereby takes part in the control of the acido-basic balance of the pulp. Yet, as a result of climate change, a steady increase of K+ content and pH of the pulp has been observed in the past twenty years. This phenomenon greatly alters grape quality and leads to wines having poor organoleptic qualities and a reduced stability.
The group is working simultaneously on two species: the model plant Arabidopsis thaliana and grapevine. It develops a strategy of translational biology based on our observation that the molecular mechanisms involved in the control and regulation of K+ transport are highly conserved between grapevine and Arabidopsis. The group is essentially working on the K+/H+ exchange mechanisms at the cell plasma membrane and at the tonoplast. We are particularly interested in the impact of abiotic stresses (temperature and drought stress) on these mechanisms.
In grapevine, the group has performed functional and molecular characterizations of homotetrameric K+ channels from the Shaker family, and shown that their activities are regulated by pH. We have developed ratiometric fluorescent probes allowing pH measurement at a distance of a few nanometers from the plasma membrane.
The aims of the present project are:
- To continue the functional and molecular characterizations of the different transport systems expressed in the grape berry at the plasma membrane (K+ Shaker channels) or at the tonoplast (TPK (two-pore K+) channels and CPA (cation-proton antiporter) transporters).
- To analyse the impact of climate change of K+ accumulation in grape berry in relation to its acidity.
- To understand the role of the vacuolar system (vacuolar remodelling, K+/H+ exchange activity) in this adaptive response, particularly through the development of new ratiometric probes allowing pH measurements in the vicinity of the tonoplast.
- To study the mechanisms controlling the regulation of the different transport systems by a search for partners (kinases, phosphatases, and others), in connexion with abiotic stresses and hormonal regulations.
- To analyse the roles of K+ channels and transporters as well as those of their regulatory partners in the control and maintenance of grape acidity in grapevine populations displaying contrasted pH.
Villette J, Cuéllar T, Zimmermann SD, Verdeil J-L, Gaillard I✉ (2019) Unique features of the grapevine VvK5.1 channel support novel functions for outward K+ channels in plants. J. Exp. Bot., (accepted)
Nieves-Cordones M, Andrianteranagna M, Cuéllar T, Chérel I, Gibrat R, Boeglin M, Moreau B, Paris N, Verdeil J-L, Zimmermann SD, Gaillard I✉ (2019) Characterization of the grapevine Shaker K+ channel VvK3.1 supports its function in massive potassium fluxes necessary for berry potassium loading and pulvinus-actuated leaf movements. New Phytol., 222(1):286-300
Chérel I✉, Gaillard I (2019) The complex fine-tuning of K+ fluxes in plants in relation to osmotic and ionic abiotic stresses. Int. J. Mol. Sci., 20(3):715
Martinière A, Gibrat R, Sentenac H, Dumont X, Gaillard I, Paris N✉ (2018) Uncovering pH at both sides of the root plasma membrane interface using noninvasive imaging. P. Natl. Acad. Sci. USA, 115(25):6488-6493
Boeglin M*, Fuglsang AT*, Luu D-T, Sentenac H, Gaillard I, Chérel I✉ (2016) Reduced expression of AtNUP62 nucleoporin gene affects auxin response in Arabidopsis. BMC Plant Biol., 16:2
Lefoulon C*, Boeglin M*, Moreau B, Véry A-A, Szponarski W, Dauzat M, Michard E, Gaillard I, Chérel I✉ (2016) The Arabidopsis AtPP2CA protein phosphatase inhibits the GORK K+ efflux channel and exerts a dominant suppressive effect on phosphomimetic-activating mutations. J. Biol. Chem., 291(12):6521-6533
Nieves-Cordones M✉, Ródenas R, Chavanieu A, Rivero RM, Martínez V, Gaillard I, Rubio F✉ (2016) Uneven HAK/KUP/KT protein diversity among angiosperms: Species distribution and perspectives. Front. Plant Sci., 7:127
Taochy C, Gaillard I, Ipotesi E, Oomen RJFJ, Leonhardt N, Zimmermann S, Peltier J-B, Szponarski W, Simonneau T, Sentenac H, Gibrat R, Boyer J-C✉ (2015) The Arabidopsisroot stele transporter NPF2.3 contributes to nitrate translocation to shoots under salt stress. Plant J., 83(3):466-479
Chérel I✉, Lefoulon C, Boeglin M, Sentenac H (2014) Molecular mechanisms involved in plant adaptation to low K+ availability. J. Exp. Bot., 65(3):833-848
Nieves-Cordones M, Chavanieu A, Jeanguenin L, Alcon C, Szponarski W, Estaran S, Chérel I, Zimmermann S, Sentenac H, Gaillard I✉ (2014) Distinct amino acids in the C-linker domain of the Arabidopsis K+ channel KAT2 determine its subcellular localization and activity at the plasma membrane. Plant Physiol., 164(3):1415-1429
Nieves-Cordones M✉, Gaillard I✉ (2014) Involvement of the S4-S5 Linker and the C-linker domain regions to voltage-gating in plant shaker channels: comparison with animal HCN and Kv channels. Plant Signal. Behav., 9(10):e972892
Cuéllar T, Azeem F, Andrianteranagna M, Pascaud F, Verdeil J-L, Sentenac H, Zimmermann S, Gaillard I✉ (2013) Potassium transport in developing fleshy fruits: The grapevine inward K+ channel VvK1.2 is activated by CIPK-CBL complexes and induced in ripening berry flesh cells. Plant J., 73(6):1006-1018
Martinière A, Bassil E, Jublanc E, Alcon C, Reguera M, Sentenac H, Blumwald E, Paris N✉ (2013) In vivo intracellular pH measurements in tobacco and Arabidopsis reveal an unexpected pH gradient in the endomembrane system. Plant Cell, 25(10):4028-4043
Martinière A✉, Desbrosses G, Sentenac H, Paris N✉ (2013) Development and properties of genetically encoded pH sensors in plants. Front. Plant Sci., 4:523
Former team members
Dec. 16, 2013 – Molecular identification, functional characterization and transcriptional regulation analysis of the Shaker potassium channel in Vitis vinifera and Arabidopsis thaliana