Blue-green fluorescence during hypersensitive cell death arises from phenylpropanoid deydrodimers.
Basem KanawatiMarko BerticFranco MoritzFelix HabermannIna ZimmerDavid MackeyPhilippe Schmitt-KopplinJoerg-Peter SchnitzlerJörg DurnerFrank GaupelsPublished in: Plant direct (2023)
Infection of Arabidopsis with avirulent Pseudomonas syringae and exposure to nitrogen dioxide (NO 2 ) both trigger hypersensitive cell death (HCD) that is characterized by the emission of bright blue-green (BG) autofluorescence under UV illumination. The aim of our current work was to identify the BG fluorescent molecules and scrutinize their biosynthesis, localization, and functions during the HCD. Compared with wild-type (WT) plants, the phenylpropanoid-deficient mutant fah1 developed normal HCD except for the absence of BG fluorescence. Ultrahigh resolution metabolomics combined with mass difference network analysis revealed that WT but not fah1 plants rapidly accumulate dehydrodimers of sinapic acid, sinapoylmalate, 5-hydroxyferulic acid, and 5-hydroxyferuloylmalate during the HCD. FAH1-dependent BG fluorescence appeared exclusively within dying cells of the upper epidermis as detected by microscopy. Saponification released dehydrodimers from cell wall polymers of WT but not fah1 plants. Collectively, our data suggest that HCD induction leads to the formation of free BG fluorescent dehydrodimers from monomeric sinapates and 5-hydroxyferulates. The formed dehydrodimers move from upper epidermis cells into the apoplast where they esterify cell wall polymers. Possible functions of phenylpropanoid dehydrodimers are discussed.
Keyphrases
- cell wall
- cell death
- cell cycle arrest
- single molecule
- wild type
- induced apoptosis
- network analysis
- living cells
- quantum dots
- energy transfer
- pi k akt
- palliative care
- mass spectrometry
- high throughput
- signaling pathway
- endoplasmic reticulum stress
- escherichia coli
- transcription factor
- electronic health record
- big data
- machine learning
- optical coherence tomography
- pseudomonas aeruginosa