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Blue-Light Induced Biosynthesis Of Ros Contributes To The Signaling Mechanism Of Arabidopsis Cryptochrome, Mohamed A. El-Esawi, Louis David Arthaut, Nathalie Jourdan, Alain D'Harlingue, Justin J. Link, Margaret Ahmad, Carlos F. Martino
Blue-Light Induced Biosynthesis Of Ros Contributes To The Signaling Mechanism Of Arabidopsis Cryptochrome, Mohamed A. El-Esawi, Louis David Arthaut, Nathalie Jourdan, Alain D'Harlingue, Justin J. Link, Margaret Ahmad, Carlos F. Martino
Biomedical Engineering and Sciences Faculty Publications
Cryptochromes are evolutionarily conserved blue light receptors with many roles throughout plant growth and development. They undergo conformational changes in response to light enabling interaction with multiple downstream signaling partners. Recently, it has been shown that cryptochromes also synthesize reactive oxygen species (ROS) in response to light, suggesting the possibility of an alternate signaling mechanism. Here we show by fluorescence imaging and microscopy that H202 and ROS accumulate in the plant nucleus after cryptochrome activation. They induce ROS-regulated transcripts including for genes implicated in pathogen defense, biotic and abiotic stress. Mutant cryptochrome alleles that are non-functional in photomorphogenesis retain the …
Blue-Light Induced Accumulation Of Reactive Oxygen Species Is A Consequence Of The Drosophila Cryptochrome Photocycle, Louis David Arthaut, Margaret Ahmad, Nathalie Jourdan, Ali Mteyrek, Maria Procopio, Mohamed A. El-Esawi, Alain D'Harlingue, Pierre Etienne Bouchet, Jacques Witczak, Carlos F. Martino
Blue-Light Induced Accumulation Of Reactive Oxygen Species Is A Consequence Of The Drosophila Cryptochrome Photocycle, Louis David Arthaut, Margaret Ahmad, Nathalie Jourdan, Ali Mteyrek, Maria Procopio, Mohamed A. El-Esawi, Alain D'Harlingue, Pierre Etienne Bouchet, Jacques Witczak, Carlos F. Martino
Biomedical Engineering and Sciences Faculty Publications
Cryptochromes are evolutionarily conserved blue-light absorbing flavoproteins which participate in many important cellular processes including in entrainment of the circadian clock in plants, Drosophila and humans. Drosophila melanogaster cryptochrome (DmCry) absorbs light through a flavin (FAD) cofactor that undergoes photoreduction to the anionic radical (FAD) redox state both in vitro and in vivo. However, recent efforts to link this photoconversion to the initiation of a biological response have remained controversial. Here, we show by kinetic modeling of the DmCry photocycle that the fluence dependence, quantum yield, and half-life of flavin redox state interconversion are consistent with the anionic radical (FAD∗-) …