Sodium Chloride Reduces Growth and Cytosolic Calcium, But Does Not Affect Cytosolic pH, in Root Hairs of Arabidopsis Thaliana L.

The study investigated the impact of sodium chloride (NaCl) on root hairs of Arabidopsis thaliana, focusing on growth, cytosolic calcium gradients, and cytosolic pH. It was found that exposure to NaCl concentrations up to 90 mM for 2 to 6 days reduced root hair extension, an effect that could be mitigated by additional extracellular calcium. NaCl exposure decreased the calcium gradient in the root hair tips, although this did not always correlate with reduced growth. Importantly, NaCl did not affect the cytosolic pH of root hairs. The findings suggested that NaCl inhibited root hair growth through changes in the calcium gradient rather than pH alterations, and short-term responses to NaCl might involve mechanisms other than changes in calcium at the root hair apex.