In:
Plant Physiology, Oxford University Press (OUP), Vol. 117, No. 1 ( 1998-05-01), p. 19-27
Abstract:
A mechanism that confers increased Al resistance in the Arabidopsis thaliana mutantalr-104 was investigated. A modified vibrating microelectrode system was used to measure H+ fluxes generated along the surface of small Arabidopsis roots. In the absence of Al, no differences in root H+ fluxes between wild type and alr-104 were detected. However, Al exposure induced a 2-fold increase in net H+ influx inalr-104 localized to the root tip. The increased flux raised the root surface pH of alr-104 by 0.15 unit. A root growth assay was used to assess the Al resistance ofalr-104 and wild type in a strongly pH-buffered nutrient solution. Increasing the nutrient solution pH from 4.4 to 4.5 significantly increased Al resistance in wild type, which is consistent with the idea that the increased net H+ influx can account for greater Al resistance in alr-104. Differences in Al resistance between wild type and alr-104 disappeared when roots were grown in pH-buffered medium, suggesting that Al resistance in alr-104 is mediated only by pH changes in the rhizosphere. This mutant provides the first evidence, to our knowledge, for an Al-resistance mechanism based on an Al-induced increase in root surface pH.
Type of Medium:
Online Resource
ISSN:
1532-2548
,
0032-0889
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
1998
detail.hit.zdb_id:
2004346-6
detail.hit.zdb_id:
208914-2
SSG:
12
