The multigene family of the H(+)-ATPase of plant plasma membranes.

Various cellular and physiological functions of plants depend on the functioning of the plasma-membrane H(+)-ATPase. The primary structure of the enzyme has recently been deduced from pma (plasma membrane H(+)-ATPase) cDNAs isolated from various higher plants. It is encoded by a multigene family including at least two major subfamilies. The pma genes are expressed in a tissue-specific manner. In addition, at least some of them are regulated at the transcriptional level. Strategies involving gene overexpression and antisense RNA have been used to obtain transgenic plants with modified PMA level. Whether individual isoforms play specific roles is discussed in the light of different experimental approaches.