Send to

Choose Destination
See comment in PubMed Commons below
Plant Physiol. 1992 Jun;99(2):415-21.

Effect of Low Root Medium pH on Net Proton Release, Root Respiration, and Root Growth of Corn (Zea mays L.) and Broad Bean (Vicia faba L.).

Author information

  • 1Institute of Plant Nutrition, Justus Liebig University, Suedanlage 6, D-6300 Giessen, Germany.


The effect of low pH on net H(+) release and root growth of corn (Zea mays L.) and broad bean (Vicia faba L.) seedlings was investigated in short-term experiments at constant pH. Broad bean was more sensitive to low pH than corn: the critical values (pH values below which net H(+) release and root growth ceased) were pH 4.00 (broad bean) and pH 3.50 (corn) at 1 millimolar Ca(2+). Both proton release and root growth were progressively inhibited as the medium pH declined. Additional Ca(2+) in the root medium helped to overcome the limitations of low pH for net H(+) release and root growth. Potassium (for corn) and abscisic acid (for broad bean) increased both net H(+) release and root growth rate at the critical pH value. It is concluded that poor root growth at low pH is caused by a lack of net H(+) release that may decrease cytoplasmic pH values. Inhibited net H(+) release at high external H(+) activity is not due to a shortage of energy supply to the H(+) ATPase. Instead, a displacement of Ca(2+) by H(+) at the external side of the plasmalemma may enhance reentry of H(+) into root cells.

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk