Articles
PHENOLIC ACIDS IN THE RESISTANCE OF WHEAT TO STEM RUST
Article number
381_74
Pages
557 – 560
Language
Abstract
There is still a controversial discussion concerning induced lignification as a rapid and effective resistance mechanism in plants infected by fungi.
Lignification is sometimes considered too slow to be involved in active defence, and it has been postulated that cell wall bound phenolic esters rather than lignin formation might be involved in plant disease resistance responses.
Histochemical and enzymic investigations have clearly demonstrated a causal involvement of lignification in hypersensitive resistance of wheat leaves to the stem rust fungus, but the contents in phenolic acids have not yet been studied in detail.
We have now investigated the infection-induced accumulation of phenolic acids in leaves of near-isogenic wheat lines highly resistant, moderatley resistant, and fully susceptible to the stem rust fungus.
No changes in the contents of free soluble, bound soluble, or bound insoluble phenolic acids were seen in infected highly resistant plants.
The content in an unidentified compound of the free soluble fraction decreased, and the content in bound soluble trans-sinapic acid increased in moderately resistant and, even more pronounced, in susceptible plants upon infection.
The results clearly show that changes in the contents of phenolic acids, including cell wall bound cinnamic acids, are not involved in resistance of wheat to stem rust.
Lignification is sometimes considered too slow to be involved in active defence, and it has been postulated that cell wall bound phenolic esters rather than lignin formation might be involved in plant disease resistance responses.
Histochemical and enzymic investigations have clearly demonstrated a causal involvement of lignification in hypersensitive resistance of wheat leaves to the stem rust fungus, but the contents in phenolic acids have not yet been studied in detail.
We have now investigated the infection-induced accumulation of phenolic acids in leaves of near-isogenic wheat lines highly resistant, moderatley resistant, and fully susceptible to the stem rust fungus.
No changes in the contents of free soluble, bound soluble, or bound insoluble phenolic acids were seen in infected highly resistant plants.
The content in an unidentified compound of the free soluble fraction decreased, and the content in bound soluble trans-sinapic acid increased in moderately resistant and, even more pronounced, in susceptible plants upon infection.
The results clearly show that changes in the contents of phenolic acids, including cell wall bound cinnamic acids, are not involved in resistance of wheat to stem rust.
Authors
P. Bärbel Menden, C. Kaum, M. Bruno Moerschbacher
Keywords
hypertensive reaction, lignin, near-isogenic lines, Puccinia graminis f. sp. tritici, Triticum aestivum
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