Rice and Phragmites: effects of organic acids on growth, root permeability, and radial oxygen loss to the rhizosphere

Citation
J. Armstrong et W. Armstrong, Rice and Phragmites: effects of organic acids on growth, root permeability, and radial oxygen loss to the rhizosphere, AM J BOTANY, 88(8), 2001, pp. 1359-1370
Citations number
56
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
AMERICAN JOURNAL OF BOTANY
ISSN journal
0002-9122 → ACNP
Volume
88
Issue
8
Year of publication
2001
Pages
1359 - 1370
Database
ISI
SICI code
0002-9122(200108)88:8<1359:RAPEOO>2.0.ZU;2-G
Abstract
Young Phragmites plants were grown in two cocktails of monocarboxylic acids (C-1-C-5) at pH 6, where the concentration of each acid was innocuous and the total undissociated (potentially toxic) concentrations were 0.35 mmol/L and 0.42 mmol/L. Rice plants were subjected to 1.5 mmol/L acetic acid at p H 4.5 (undissociated concentration = 1.05 mmo/L). In Phragmites, each cockt ail curtailed root growth especially and induced premature shoot senescence . In both species, after 3-5 d of treatment, radial oxygen loss (ROL) from apical regions of adventitious roots, and from Phragmites laterals, was red uced to very low values and associated with cell wall lignification and sub erization in the surface cell layers. At later stages of treatment, rice re sponded to acetic acid in similar ways to Phragmites, with the development of intercellular and callus type occlusions in the gas space system, vascul ar blockages, and the failure of laterals to emerge. The results are releva nt to the supply of oxygen from Phragmites roots to sediments for the phyto purification of waste waters, to the efflux of methane and carbon dioxide f rom wetlands, and to rice cultivation.