Elucidation of the Mechanisms Underlying Hypo-osmotically Induced Turgor Pressure Regulation in the Marine Alga Valonia utricularis

Elucidation of the Mechanisms Underlying Hypo-osmotically Induced Turgor Pressure Regulation in... Exposure of the giant marine alga Valonia utricularis to acute hypo-osmotic shocks induces a transient increase in turgor pressure and subsequent back-regulation. Separate recording of the electrical properties of tonoplast and plasmalemma together with turgor pressure was performed by using a vacuolar perfusion assembly. Hypo-osmotic turgor pressure regulation was inhibited by external addition of 300 μM of the membrane-permeable ion channel blocker 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB). In the presence of 100 μM NPPB, regulation could only be inhibited by simultaneous external addition of 200 μM 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS), a membrane-impermeable inhibitor of Cl− transport. At concentrations of about 100 μM, NPPB seems to selectively inhibit Cl− transporters in the tonoplast and K+ transporters in the plasmalemma, whereas 300 μM NPPB inhibits K+ and Cl− transporters in both membranes. Evidence was achieved by measuring the tonoplast and plasmalemma conductances (G t and G p) in low-Cl− and K+-free artificial seawater. Inhibition of turgor pressure regulation by 300 μM NPPB was accompanied by about 85% reduction of G t and G p. Vacuolar addition of sulfate, an inhibitor of tonoplast Cl− transporters, together with external addition of DIDS and Ba2+ (an inhibitor of K+ transporters) also strongly reduced G p and G t but did not affect hypo-osmotic turgor pressure regulation. These and many other findings suggest that KCl efflux partly occurs via electrically silent transport systems. Candidates are vacuolar entities that are disconnected from the huge and many-folded central vacuole or that become disconnected upon disproportionate swelling of originally interconnected vacuolar entities upon acute hypo-osmotic challenge. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Membrane Biology Springer Journals

Elucidation of the Mechanisms Underlying Hypo-osmotically Induced Turgor Pressure Regulation in the Marine Alga Valonia utricularis

Loading next page...
 
/lp/springer_journal/elucidation-of-the-mechanisms-underlying-hypo-osmotically-induced-55oyQQO7qt
Publisher
Springer-Verlag
Copyright
Copyright © 2007 by Springer Science+Business Media, Inc.
Subject
Life Sciences; Biochemistry, general; Human Physiology
ISSN
0022-2631
eISSN
1432-1424
D.O.I.
10.1007/s00232-006-0047-9
Publisher site
See Article on Publisher Site

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches

$49/month

Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

$588

$360/year

billed annually
Start Free Trial

14-day Free Trial