Root and Root Hair Growth in Relation to Supply and Internal Mobility of Calcium

The study on oat seedlings demonstrated that root hair elongation was greatest in moist air, despite lower calcium content compared to complete nutrient solutions. This suggested that minimal calcium might suffice for root hair growth if roots are not exposed to toxic ionic environments. In calcium-deficient solutions, root hair deformation and suppressed elongation were attributed to the toxicity of other ions rather than calcium deficiency, as no calcium loss from roots was observed. Experiments with 45Ca confirmed that calcium from seeds was transported to roots and utilized in hair elongation, but calcium absorbed by one root was not transferred to another within the same seedling.