Salinity Tolerance of Two Potato Cultivars () Correlates With Differences in Vacuolar Transport Activity.

Potato is an important cultivated crop species and since it is moderately salt sensitive there is a need to develop more salt tolerant cultivars. A high activity of Na transport across the tonoplast in exchange for H is essential to reduce Na toxicity. The proton motive force (PMF) generated by the V-H-ATPase and the V-H-PPase energizes the Na(K)/H antiport.

Differences in proton pumping and Na/H exchange at the leaf cell tonoplast between a halophyte and a glycophyte.

The tonoplast Na(+)/H(+) antiporter and tonoplast H(+) pumps are essential components of salt tolerance in plants. The objective of this study was to investigate the transport activity of the tonoplast Na(+)/H(+) antiporter and the tonoplast V-H(+)-ATPase and V-H(+)-PPase in a highly tolerant salt-accumulating halophyte, Salicornia dolichostachya, and to compare these transport activities with activities in the related glycophyte Spinacia oleracea. Vacuolar membrane vesicles were isolated by density gradient centrifugation, and the proton transport and hydrolytic activity of both H(+) pumps were studied.

Hyperacidification of vacuoles by the combined action of two different P-ATPases in the tonoplast determines flower color.

The acidification of endomembrane compartments is essential for enzyme activities, sorting, trafficking, and trans-membrane transport of various compounds. Vacuoles are mildly acidic in most plant cells because of the action of V-ATPase and/or pyrophosphatase proton pumps but are hyperacidified in specific cells by mechanisms that remained unclear. Here, we show that the blue petal color of petunia ph mutants is due to a failure to hyperacidify vacuoles.

Effect of salt stress on growth, Na+ accumulation and proline metabolism in potato (Solanum tuberosum) cultivars.

Potato (Solanum tuberosum) is a major crop world-wide and the productivity of currently used cultivars is strongly reduced at high soil salt levels. We compared the response of six potato cultivars to increased root NaCl concentrations. Cuttings were grown hydroponically and treated with 0 mM, 60 mM and 180 mM NaCl for one week.