Identification and biochemical characterization of the plasma-membrane H+-ATPase in guard cells of Vicia faba L.

Becker, Dirk; Zeilinger, Carsten; Lohse, Gabi; Depta, H.; Hedrich, Rainer

doi:10.1007/bf00195673

Cited by 43 publications

(22 citation statements)

References 38 publications

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“…The presence of an H + -ATPase in the epidermis of the roots and in guard cells, which is shown for PMA1 in this study, has been known for a long time and confirmed by immunolocalization (Villalba et al, 1991;Samuels et al, 1992). Also, H + -ATPase-containing plasma membranes have been isolated from guard cells (Becker et al, 1993). These studies, however, made no distinction between single isoforms of the H + -ATPase, and we are not certain whether the immunodetections revealed all the subfamilies of ATPases (as defined in Moriau et al, 1993).…”

Section: Physiology and Tissue-specific Expressionsupporting

confidence: 72%

A plant plasma membrane proton-ATPase gene is regulated by development and environment and shows signs of a translational regulation.

et al. 1994

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A proton-pumping ATPase is present in the plasma membrane of plant cells where it sustains transport-related functions. This enzyme is encoded by a family of genes that shows signs of both transcriptional and post-transcriptional regulation. The regulation of pma1, one of the Nicotiana plumbaginifolia H+-ATPase genes, was characterized with the help of the beta-glucuronidase (gusA) receptor gene in transgenic plants. pma1 is active in the root epidermis, the stem cortex, and guard cells. This activity depends on developmental and growth conditions. For instance, pma1 activity in guard cells was strongly enhanced when the plant material (young seedlings or mature leaves) was incubated in liquid growth medium. pma1 is also expressed in several tissues of the reproductive organs where active transport is thought to occur but where scarcely any ATPase activity has been identified, namely in the tapetum, the pollen, the transmitting tissue, and the ovules. Several pma genes have a long 5'untranslated region (leader sequence) containing an upstream open reading frame (URF). Analysis of translational and transcriptional fusions with gusA in transgenic plants suggests that the pma1 leader sequence might activate translation of the main open reading frame, even though the URF is translated by a large majority of the scanning ribosomes. As confirmation, transient expression experiments showed that the pma1 leader causes a fourfold post-transcriptional increase of main open reading frame expression. Deletion of the URF by site-directed mutagenesis stimulated the main open reading frame translation 2.7-fold in an in vitro translational assay. These results are consistent with a regulatory mechanism involving translation reinitiation. Altogether, they suggest a fine, multilevel regulation of H+-ATPase activity in the plant.

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Section: Physiology and Tissue-specific Expressionsupporting

confidence: 72%

A plant plasma membrane proton-ATPase gene is regulated by development and environment and shows signs of a translational regulation.

et al. 1994

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“…Proton pumping in the plasma membranes of mesophyll cells was much lower than that in microsomal membranes of guard cells (Figures 2A and 9A) on the protein basis of these membranes. This could be due in part to the high density of the pump in the plasma membranes of guard cells (Villalba et al, 1991;Becker et al, 1993). Pumping in the membrane preparations from mesophyll cells was inhibited by Ca2+ in a manner similar to that in the microsomal membranes of guard cells ( Figure 9A).…”

Section: Activation Of H+-atpase By Treatment Of the Epidermis With Cmentioning

confidence: 86%

Cytosolic Concentration of Ca2+ Regulates the Plasma Membrane H+-ATPase in Guard Cells of Fava Bean.

1995

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Opening of the stomata i s driven by the light-activated plasma membrane proton pumping ATPase, although the activation and inactivation mechanism of the enzyme is not known. In this study, we show that the H+-ATPase in guard CellS is reversibly inhibited by Ca2+ at physiological concentrations. Isolated microsomal membranes of guard cell protoplasts from fava bean exhibited vanadate-sensitive, ATP-dependent proton pumping. The activity was inhibited almost completely by 1 pM Ca2+ with a half-inhibitory concentration at 0.3 pM and was restored immediately by the addition of 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid, a calcium chelating reagent. Similar reversible inhibition by Ca2+ was shown by the generation of electrical potential in the membranes. Activity of ATP hydrolysis was inhibited similarly by Ca2+ in the same membrane preparations. The addition of 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid and EGTA, Ca2+ chelators, to epidermal peels of fava bean induced stomatal opening in the dark, and the opening was suppressed by vanadate. This suggests that the lowered cytosolic Ca2+ activated the proton pump i n vivo and that the activated pump elicited stomatal opening. lnhibition of H+-ATPase by Ca2+ may depolarize the membrane potential and could be a key step in the process of stomatal closing through activation of the anion channels. Furthermore, similar inhibition of the proton pumping and ATP hydrolysis by Ca2+ was found in isolated plasma membranes of mesophyll cells of fava bean. These results suggest that Ca2+ regulates the activity of plasma membrane H+-ATPases in higher plant cells, thereby modulating stomatal movement and other cellular processes i n plants.

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“…We thus predicted that e.g. the guard cell plasma membrane and/or vacuolar membrane is equipped with ion transporters of high abundance or transport capacity [6,83]. Indeed, when comparing the single channel amplitude (turn over) of the SV-type channels (Table 3) the guard cell representative is by far the most conductive.…”

Section: Aleuron Cells Of Growing Seeds or Cells In The Root Tip Or Gmentioning

confidence: 96%

Green circuits ? The potential of plant specific ion channels

Hedrich¹,

Becker²

1994

Plant Mol Biol

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Identification and biochemical characterization of the plasma-membrane H+-ATPase in guard cells of Vicia faba L.

Cited by 43 publications

References 38 publications

A plant plasma membrane proton-ATPase gene is regulated by development and environment and shows signs of a translational regulation.

A plant plasma membrane proton-ATPase gene is regulated by development and environment and shows signs of a translational regulation.

Cytosolic Concentration of Ca2+ Regulates the Plasma Membrane H+-ATPase in Guard Cells of Fava Bean.

Green circuits ? The potential of plant specific ion channels

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