Skip Navigation

This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (8)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Ramadan, T.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Ramadan, T.
Agricola
Right arrow Articles by Ramadan, T.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Annals of Botany 87: 259-266, 2001
© 2001 Annals of Botany Company

Dynamics of Salt Secretion by Sporobolus spicatus(Vahl) Kunth from Sites of Differing Salinity

T. Ramadan

Botany Department, Faculty of Science, Assiut University, 71516, Assiut, Egypt

Received: 14 October 1999 ; Accepted: 30 October 2000

Secretion of salts by bicellular salt glands and the water relations of the grass Sporobolus spicatus were investigated at four sites along the coast of the Red Sea in Egypt that differed in the extremity of salinity and drought. Salt eliminated by the leaves was similar in its composition at all sites. Na+and Cl-were the dominant ions in the soil, and together comprised about 93% of the dry weight of secreted salt. The molar ratio of K+:Na+in the plant leaves was more than ten-fold that in the interstitial soil solution and thirteen-times that in the secreted salts, reflecting the high selectivity of the secretion mechanism for Na+. The concentration of Na+in the solution transported to the leaves between 0900 and 1500 h was less than 0.1% of that in the soil solution. Accumulation of salts by the plant shoots, which increased with increasing soil salinity and drought, was maximal during the day when the extent of secretion greatly reduced. The ionic osmotic potential ({psi}i) of leaves was lowest at midday and this was mainly due to the decreasing water content and increasing accumulation of NaCl which contributed about 68% of total leaf ionic osmotic potential. Increasing secretion during the night resulted in removal of salts that were accumulated during the day. In this way the mineral content of the plant was regulated and compartments in the leaves that contained salt during the day were emptied during the night to become available for a new supply the following day. Copyright 2001 Annals of Botany Company

Drought, osmoregulation, salinity, salt secretion, Sporobolus spicatus, transpiration


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Am. J. Bot.Home page
H. L. Bell and J. W. O'Leary
Effects of salinity on growth and cation accumulation of Sporobolus virginicus (Poaceae)
Am. J. Botany, October 1, 2003; 90(10): 1416 - 1424.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.