The ions extruded by auxin during cell wall extension is

Options

(a) potassium
(b) sodium
(c) magnesium
(d) hydrogen

Correct Answer:

hydrogen

Explanation:

IAA brings about cell wall extension by activating proton pump which maintains the cell wall in an acidic condition of around 4 pH. Under these conditions, the cell wall pressure is reduced and water enters the cell, accompained by an increase in cell volume. As the cell increases in volume, the new cell wall material becames necessary to stabilise the wall. IAA is naturally occuring auxin.It also promotes cell enlargements, cell division in vascular cambium, root intiation and apical dominance.