Aluminium-induced changes in root epidermal cell patterning, a distinctive feature of hyperresistance to Al in Brachiaria decumbens.
J Inorg Biochem
; 105(11): 1477-83, 2011 Nov.
Article
em En
| MEDLINE
| ID: mdl-22099157
ABSTRACT
Brachiaria, a genus of forage grasses of African origin, is gaining considerable importance because of both its nutritional value and its high stress resistance. An extraordinary resistance to Al toxicity has been reported in B. decumbens. The mechanisms of this hyperresistance are still unknown. This study explores the localization of Al in two contrasting Brachiaria species, the hyperresistant B. decumbens and the less resistant B. brizantha. Scanning Electron Microscope/Energy Dispersive Spectrometry, confocal fluorescence microscopy and optical microscopy of lumogallion or morin-stained roots was performed. Species differences in Al resistance were evident at 32 µM Al(3+) activity in low ionic strength full nutrient solution containing Si. Roots of B. decumbens accumulated less Al than those of B. brizantha. Moreover, location and Al form seemed different. In B. decumbens Al accumulation was localized in hot spots of high Al concentrations. These sites with high Al accumulation mainly correspond to root hairs. B. brizantha exhibited a more even distribution of Al in cell walls of the root tip. Analysis of soluble phenolic substances in roots revealed species differences in response to Al. An Al-induced increase of chlorogenic acid concentrations was found in B. decumbens but not in B. brizantha. Taken together the results suggest a possible role for chlorogenic acid as a primer for changes in root epidermal cell patterning that may contribute to the Al hyperresistance in B. decumbens.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cloretos
/
Compostos de Alumínio
/
Raízes de Plantas
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Epiderme Vegetal
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Brachiaria
Idioma:
En
Revista:
J Inorg Biochem
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Espanha