Apoplast acidification is not a necessary determinant for the resistance of maize in the first phase of salt stress

In previous studies, a relation between plant growth during the first phase of salt stress and cell‐wall acidification was shown for differently resistant maize genotypes. In the present study, plants of the salt‐sensitive maize (Zea mays L.) cv. Pioneer 3906 and the salt‐resistant genotype SR 12, grown under 100 mM NaCl, showed a similar decrease in plasmalemma H⁺‐ATPase activity, while SR 12 showed less growth reduction than Pioneer 3906. From this it is concluded that maintenance of apoplast acidification is not necessary for better plant growth during the first phase of salt stress.