TY - JOUR 
A1 - Franco-Navarro, Juan D.
AU - Brumós, Javier
AU - Rosales, Miguel A.
AU - Cubero-Font, Paloma
AU - Talón, Manuel
AU - Colmenero-Flores, José M.
T1 - Chloride regulates leaf cell size and water relations in tobacco plants
Y1 - 2016
SN - 1460-2431
UR - http://hdl.handle.net/20.500.11939/6444
AB - Chloride (Cl–) is a micronutrient that accumulates to macronutrient levels since it is normally available in nature and
actively taken up by higher plants. Besides a role as an unspecific cell osmoticum, no clear biological roles have been
explicitly associated with Cl– when accumulated to macronutrient concentrations. To address this question, the glycophyte
tobacco (Nicotiana tabacum L. var. Habana) has been treated with a basal nutrient solution supplemented
with one of three salt combinations containing the same cationic balance: Cl–-based (CL), nitrate-based (N), and
sulphate+phosphate-based (SP) treatments. Under non-saline conditions (up to 5 mM Cl–) and no water limitation,
Cl– specifically stimulated higher leaf cell size and led to a moderate increase of plant fresh and dry biomass mainly
due to higher shoot expansion. When applied in the 1–5 mM range, Cl– played specific roles in regulating leaf osmotic
potential and turgor, allowing plants to improve leaf water balance parameters. In addition, Cl– also altered water relations
at the whole-plant level through reduction of plant transpiration. This was a consequence of a lower stomatal
conductance, which resulted in lower water loss and greater photosynthetic and integrated water-use efficiency. In
contrast to Cl–, these effects were not observed for essential anionic macronutrients such as nitrate, sulphate, and
phosphate. We propose that the abundant uptake and accumulation of Cl– responds to adaptive functions improving
water homeostasis in higher plants.
KW - Beneficial nutrients
KW - Chloride nutrition
KW - Water relations
KW - Water-use efficiency
KW - WUE
KW - F62  Plant physiology - Growth and development
KW - Growth
KW - Osmotic potential
KW - Turgor
KW - Water potential
KW - Water balance
LA - en
PB - Oxford University Press
ER -