Relative importance of osmotic-stress and ion-specific effects on ABA-mediated inhibition of leaf expansion growth in Phaseolus vulgaris |
| |
Authors: | E. Montero,C. Cabot,CH. Poschenrieder,& J. Barcelo |
| |
Affiliation: | Departament de Biologia Ambiental, Universitat de les Illes Balears, Car. de Valldemossa km. 7,5, 07071 Palma de Mallorca, and ,;Departament de Fisiologia Vegetal, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain |
| |
Abstract: | The osmotic and ion-specific components of salt-induced inhibition of leaf expansion growth were investigated in beans grown from 12 h to several days in either NaCl-containing solution cultures, an isosmotic concentrated macronutrient solution, or a vermiculite–compost mixture with low Na+ but high Cl– availability. Inhibition of leaf expansion and leaf ABA increase was more intense in the NaCl than in the isosmotic macronutrient treatment. Root Na+ was highly correlated to inhibition of leaf expansion and leaf or xylem sap ABA. When Na+ was sequestered in soil, salinized plants showed no reduction in leaf expansion or ABA increase, regardless of the presence of high leaf Cl– concentrations. Stomatal conductance exhibited an exponential relationship with the reciprocal value of xylem sap ABA. Our results indicate that an ion-specific effect caused by Na+ in roots may account for an ABA-mediated reponse of both stomatal closure and leaf expansion inhibition. |
| |
Keywords: | Phaseolus vulgaris L. ABA beans leaf expansion salt stress stomatal conductance |
|
|