Decrease in membrane hydraulic conductance of rhizodermal cells under nitrate deficit is related to acidification at the root surface

Decrease in membrane hydraulic conductance of rhizodermal cells under nitrate deficit is related... Barley seedlings (Hordeum vulgare L.) were grown on porous plates submerged in Knop medium at pH 6.0 (control) and in a similar nutrient solution where NO 3 − was replaced with Cl− (treatment); in some treatments Mes buffer (10–20 mM, pH 6.0) was added to the medium. In the absence of buffer, the pH of the medium shifted towards the alkaline region in the presence of NO 3 − and to the acidic region in the presence of Cl−, with the total shift of no more than 0.3 pH units per day. The replacement of NO 3 − with Cl− (in a buffer-free medium) decreased the hydraulic membrane conductance of rhizodermal cells (L p) within a 4-h period; after one day L p settled at approximately 50% of its initial value observed in untreated plants. When the removal of nitrate from the medium was accompanied by the addition of buffer, no changes in L p were observed over a 1-day period. The perfusion of external solution (at a rate of 10 mm/s) made it possible to control pH in the proximity to root surface (pHs). These experiments showed that L p was independent of the surface pH in the pHs range 7.0–5.0, whereas at pHs = 4.5 L p decreased within 15 min to a steady-state level of about 50% of the control value. It is concluded that the reduction of L p under nitrate deficit was related to acidification of the medium near the root surface. The acidic pH shift could be caused by the cessation of proton/nitrate symport and by activation of the plasmalemma H+-pump, related to changes in the cytosolic pH-stat. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Russian Journal of Plant Physiology Springer Journals

Decrease in membrane hydraulic conductance of rhizodermal cells under nitrate deficit is related to acidification at the root surface

Loading next page...
 
/lp/springer_journal/decrease-in-membrane-hydraulic-conductance-of-rhizodermal-cells-under-W3FZ0OOTv0
Publisher
SP MAIK Nauka/Interperiodica
Copyright
Copyright © 2008 by MAIK Nauka
Subject
Life Sciences; Plant Sciences ; Plant Physiology
ISSN
1021-4437
eISSN
1608-3407
D.O.I.
10.1134/S1021443708050051
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