title: The chlorophyllases AtCLH1 and AtCLH2 are not essential for senescence-related chlorophyll breakdown in Arabidopsis thaliana.
abstract: One important reaction of chlorophyll (chl) breakdown during plant senescence is the removal of the lipophilic phytol moiety by chlorophyllase. AtCLH1 and AtCLH2 were considered to be required for this reaction in Arabidopsis thaliana. Here we present evidence against this assumption. Using green fluorescent protein fusions, neither AtCLH isoform localizes to chloroplasts, the predicted site of chlorophyll breakdown. Furthermore, clh1 and clh2 single and double knockout lines are still able to degrade chlorophyll during senescence. From our data we conclude that AtCLHs are not required for senescence-related chlorophyll breakdown in vivo and propose that genuine chlorophyllase has not yet been molecularly identified.
authors.affiliation: Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Schenk
authors.forename: Silvia
authors.initials: S
authors.lastname: Schelbert
authors.forename: Marion
authors.initials: M
authors.lastname: Kanwischer
authors.forename: Eliezer E
authors.initials: EE
authors.lastname: Goldschmidt
authors.forename: Peter
authors.initials: P
authors.lastname: Dörmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Hörtensteiner
mesh_terms: D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism; D002384:Catalysis; D002734:Chlorophyll / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics / Q000302:isolation & purification; D003624:Darkness; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010088:Oxidoreductases / Q000378:metabolism; D010105:Oxygenases / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified
chemical_list: D051017:Apoptosis Regulatory Proteins; D029681:Arabidopsis Proteins; D018744:DNA, Plant; D007527:Isoenzymes; D002734:Chlorophyll; D010088:Oxidoreductases; D010105:Oxygenases; C112915:pheide a oxygenase; C408689:ACD2 protein, Arabidopsis; D002265:Carboxylic Ester Hydrolases; C019875:chlorophyllase