| RRC ID |
30750
|
| Author |
Christ B, Süssenbacher I, Moser S, Bichsel N, Egert A, Müller T, Kräutler B, Hörtensteiner S.
|
| Title |
Cytochrome P450 CYP89A9 is involved in the formation of major chlorophyll catabolites during leaf senescence in Arabidopsis.
|
| Journal |
Plant Cell
|
| Abstract |
Nonfluorescent chlorophyll catabolites (NCCs) were described as products of chlorophyll breakdown in Arabidopsis thaliana. NCCs are formyloxobilin-type catabolites derived from chlorophyll by oxygenolytic opening of the chlorin macrocycle. These linear tetrapyrroles are generated from their fluorescent chlorophyll catabolite (FCC) precursors by a nonenzymatic isomerization inside the vacuole of senescing cells. Here, we identified a group of distinct dioxobilin-type chlorophyll catabolites (DCCs) as the major breakdown products in wild-type Arabidopsis, representing more than 90% of the chlorophyll of green leaves. The molecular constitution of the most abundant nonfluorescent DCC (NDCC), At-NDCC-1, was determined. We further identified cytochrome P450 monooxygenase CYP89A9 as being responsible for NDCC accumulation in wild-type Arabidopsis; cyp89a9 mutants that are deficient in CYP89A9 function were devoid of NDCCs but accumulated proportionally higher amounts of NCCs. CYP89A9 localized outside the chloroplasts, implying that FCCs occurring in the cytosol might be its natural substrate. Using recombinant CYP89A9, we confirm FCC specificity and show that fluorescent DCCs are the products of the CYP89A9 reaction. Fluorescent DCCs, formed by this enzyme, isomerize to the respective NDCCs in weakly acidic medium, as found in vacuoles. We conclude that CYP89A9 is involved in the formation of dioxobilin-type catabolites of chlorophyll in Arabidopsis.
|
| Volume |
25(5)
|
| Pages |
1868-80
|
| Published |
2013-5-1
|
| DOI |
10.1105/tpc.113.112151
|
| PII |
tpc.113.112151
|
| PMID |
23723324
|
| PMC |
PMC3694711
|
| MeSH |
Arabidopsis / genetics*
Arabidopsis / metabolism
Arabidopsis / physiology
Arabidopsis Proteins / genetics*
Arabidopsis Proteins / metabolism
Chlorophyll / chemistry
Chlorophyll / metabolism*
Chromatography, High Pressure Liquid
Cytochrome P-450 Enzyme System / genetics*
Cytochrome P-450 Enzyme System / metabolism
Fluorescence
Gene Expression Regulation, Plant
Green Fluorescent Proteins / genetics
Green Fluorescent Proteins / metabolism
Mesophyll Cells / metabolism
Microscopy, Confocal
Molecular Structure
Mutagenesis, Insertional
Plant Leaves / genetics*
Plant Leaves / metabolism
Plant Leaves / physiology
Plants, Genetically Modified
Reverse Transcriptase Polymerase Chain Reaction
Spectrometry, Mass, Electrospray Ionization
Spectrophotometry
|
| IF |
9.618
|
| Times Cited |
67
|
|
WOS Category
|
PLANT SCIENCES
BIOCHEMISTRY & MOLECULAR BIOLOGY
CELL BIOLOGY
|
| Resource |
| Arabidopsis / Cultured plant cells, genes |
pda02355 |
