Cytochrome P450 CYP89A9 Is Involved in the Formation of Major Chlorophyll Catabolites during Leaf Senescence in Arabidopsis
Open Access
- 1 May 2013
- journal article
- Published by Oxford University Press (OUP) in THE PLANT CELL ONLINE
- Vol. 25 (5), 1868-1880
- https://doi.org/10.1105/tpc.113.112151
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.Keywords
This publication has 64 references indexed in Scilit:
- Structures of Chlorophyll Catabolites in Bananas (Musa acuminata) Reveal a Split Path of Chlorophyll Breakdown in a Ripening FruitChemistry – A European Journal, 2012
- A Dioxobilane as Product of a Divergent Path of Chlorophyll Breakdown in Norway MapleAngewandte Chemie, 2011
- How the Colourless ‘Nonfluorescent’ Chlorophyll Catabolites RustChemistry – A European Journal, 2011
- Chlorophyll Catabolites – Chemical and Structural Footprints of a Fascinating Biological PhenomenonEuropean Journal of Organic Chemistry, 2008
- Blue Luminescence of Ripening BananasAngewandte Chemie, 2008
- ATTED-II provides coexpressed gene networks for ArabidopsisNucleic Acids Research, 2008
- A yellow chlorophyll catabolite is a pigment of the fall coloursPhotochemical & Photobiological Sciences, 2008
- In Vivo Participation of Red Chlorophyll Catabolite Reductase in Chlorophyll BreakdownTHE PLANT CELL ONLINE, 2007
- Transcription Analysis of Arabidopsis Membrane Transporters and Hormone Pathways during Developmental and Induced Leaf SenescencePlant Physiology, 2006
- Identification of a Vacuolar Sucrose Transporter in Barley and Arabidopsis Mesophyll Cells by a Tonoplast Proteomic ApproachPlant Physiology, 2006