Root elongation in saline solution related to calcium binding to root cell plasma membranes

摘要: To gain a better understanding of the relations between root elongation and amount Ca2+ bound to plasma membrane (PM), melon plants were grown in aerated solutions containing different concentrations CaCl2 with various NaCl or mannitol. With increasing external mannitol, was suppressed. Addition medium alleviated inhibition by high Na+, but not Root media correlated computed PM. A model describing relative (RRL) under salt stress developed. This takes into account osmotic potential growing solution (based on mannitol experiments) Calcium binding calculated applying Gouy-Chapman-Stern sorption using same parameters deduced from studies PM vesicles. combines electrostatic theory competitive at surface. The for RRL allowed computation critical value fraction negative sites needed nearly optimal (95%) elongation. Any decrease below this decreased RRL. Honey Dew (salt-resistant cv.) greater than that Eshkolit Ha'Amaqim (salt-sensitive stress. Nearly growth occurred when 40% 51% total charged Ca2+, respectively. effect suppression two cultivars. our knowledge, report provides first fully quantitative estimates PM-bound toxicity.