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Impact of pulsed UV‐B stress exposure on plant performance: How recovery periods stimulate secondary metabolism while reducing adaptive growth attenuation
Author(s) -
Höll Janine,
Lindner Sonja,
Walter Hannah,
Joshi Drishti,
Poschet Gernot,
Pfleger Sina,
Ziegler Tobias,
Hell Rüdiger,
Bogs Jochen,
Rausch Thomas
Publication year - 2019
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.13409
Subject(s) - mutant , repressor , biophysics , wild type , metabolite , chemistry , gene expression , transcription (linguistics) , gene , ultraviolet , plant growth , microbiology and biotechnology , biochemistry , biology , horticulture , materials science , linguistics , philosophy , optoelectronics
Upon continuous stress exposure, plants display attenuated metabolic stress responses due to regulatory feedback loops. Here, we have tested the hypothesis that pulsed stress exposure with intervening recovery periods should affect these feedback loops, thereby causing increased accumulation of stress‐induced metabolites. The response of Arabidopsis plantlets to continuous UV‐B exposure (C uv ) was compared with that of pulsed UV‐B exposure (P uv ). The differential responses to P uv versus C uv were monitored at the level of gene expression and metabolite accumulation, using wild type (WT) and different mutant lines. In comparison with C uv , P uv increased sinapyl and flavonol (S + F) content, whereas adaptive growth attenuation was reduced. Furthermore, in a myb4 mutant (AtMYB4, repressor‐type R2R3‐MYB transcription factor), the S + F content was increased only for C uv , but not beyond the level for P uv observed in WT. These observations and the ability of AtMYB4 to repress AtMYB12/AtMYB111‐mediated activation of target gene promoters ( pCHS and pFLS ) indicate that the increase of S + F content after P uv observed in WT plants results from reduced feedback inhibition by AtMYB4. The results support the notion that stress‐induced metabolic changes not necessarily cause a growth penalty. Furthermore, the observed P uv ‐induced increase in flavonol accumulation may stimulate reevaluation of commercial plant production practices.