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Perception of low red:far‐red ratio compromises both salicylic acid‐ and jasmonic acid‐dependent pathogen defences in A rabidopsis
Author(s) -
Wit Mieke,
Spoel Steven H.,
SanchezPerez Gabino F.,
Gommers Charlotte M. M.,
Pieterse Corné M. J.,
Voesenek Laurentius A. C. J.,
Pierik Ronald
Publication year - 2013
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12203
Subject(s) - jasmonic acid , salicylic acid , phytochrome , shade avoidance , far red , biology , pathogen , psychological repression , transcription (linguistics) , transcription factor , activator (genetics) , wrky protein domain , microbiology and biotechnology , biochemistry , botany , red light , mutant , gene expression , gene , arabidopsis , linguistics , philosophy
Summary In dense stands of plants, such as agricultural monocultures, plants are exposed simultaneously to competition for light and other stresses such as pathogen infection. Here, we show that both salicylic acid ( SA )‐dependent and jasmonic acid ( JA )‐dependent disease resistance is inhibited by a simultaneously reduced red:far‐red light ratio ( R : FR ), the early warning signal for plant competition. Conversely, SA ‐ and JA ‐dependent induced defences did not affect shade‐avoidance responses to low R : FR . Reduced pathogen resistance by low R : FR was accompanied by a strong reduction in the regulation of JA ‐ and SA ‐responsive genes. The severe inhibition of SA ‐responsive transcription in low R : FR appeared to be brought about by the repression of SA ‐inducible kinases. Phosphorylation of the SA ‐responsive transcription co‐activator NPR 1, which is required for full induction of SA ‐responsive transcription, was indeed reduced and may thus play a role in the suppression of SA ‐mediated defences by low R : FR ‐mediated phytochrome inactivation. Our results indicate that foraging for light through the shade‐avoidance response is prioritised over plant immune responses when plants are simultaneously challenged with competition and pathogen attack.