Séminaire IBIP – Série thématique « fruit and seed »
Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)

Jeudi 23 juin 2016
Salle 108 (Cœur d’Ecole) à 14h

Chloride as a beneficial macronutrient in plants: biological functions and regulation

José M. Colmenero-Flores
Instituto de Recursos Naturales y Agrobiología (CSIC) – Av. Reina Mercedes 10, 41012 – Sevilla

In the agronomic context, chloride (Cl–) has been generally considered a toxic anion rather than a plant nutrient (Colmenero-Flores et al., 2007; Brumós et al., 2009; Brumós et al., 2010). However, we have recently shown that in addition to an essential micronutrient, chloride is a beneficial macronutrient (Franco-Navarro et al., 2016). Under non-saline conditions Cl– specifically stimulates higher leaf cell size and leads to a moderate increase of plant fresh and dry biomass mainly due to higher shoot expansion. Cl– plays specific roles in regulating leaf osmotic potential and turgor, allowing plants to improve leaf water balance parameters. In addition, Cl– regulates water relations at the whole plant level through reduction of plant transpiration. This is a consequence of a lower stomatal conductance, which results in lower water loss and greater photosynthetic and integrated water-use efficiency (Franco-Navarro et al., 2016). The following open questions about chloride accumulation at macronutrient levels will be addressed: i) does Cl– improve resistance to water deficit?; ii) why Cl–-mediated reduction of stomatal conductance does not result in reduction of net photosynthetic rate?; iii) why nitrate assimilation is not adversely affected?; iv) How is Cl– accumulation and Cl–/NO3– interaction regulated at the molecular level?
We propose that the abundant uptake and accumulation of Cl– responds to adaptive functions improving water homeostasis, drought tolerance, and nitrate- and Carbon-use efficiency in plants. In addition, molecular mechanisms regulating the distribution of Cl– between root and shoot according to changing environmental conditions will be proposed.

Brumós, J., J.M. Colmenero-Flores, A. Conesa, P. Izquierdo, G. Sanchez, D.J. Iglesias, M.F. Lopez-Climent, A. Gomez-Cadenas, and M. Talon. 2009. Membrane transporters and carbon metabolism implicated in chloride homeostasis differentiate salt stress responses in tolerant and sensitive Citrus rootstocks. Functional & Integrative Genomics 9:293-309

Brumós, J., M. Talón, Bouhlal, R. and J.M. Colmenero-Flores. 2010. Cl– homeostasis in includer and excluder citrus rootstocks: transport mechanisms and identification of candidate genes. Plant, Cell & Environment 33:2012-2027.

Colmenero-Flores, J.M., G. Martinez, G. Gamba, N. Vazquez, D.J. Iglesias, J. Brumos, and M. Talon. 2007. Identification and functional characterization of cation-chloride cotransporters in plants. The Plant Journal 50:278-292.

Franco-Navarro, J.D., J. Brumós, M.A. Rosales, P. Cubero, M. Talón, and J.M. Colmenero-Flores. 2016. Chloride regulates leaf cell size and water relations in tobacco plants. Journal of Experimental Botany 67:873-891.

Contact : Miguel Rosales

Contacts IBIP :
Sabine Zimmermann
Alexandre Martiniere
Christine Granier
Chantal Baracco