کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8354432 1541924 2015 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Linking chlorophyll biosynthesis to a dynamic plastoquinone pool
ترجمه فارسی عنوان
اتصال بیوسنتز کلروفیل به یک پلاستو کوینون پویا
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش گیاه شناسی
چکیده انگلیسی
Chlorophylls are essential cofactors in photosynthesis. All steps in the chlorophyll pathway are well characterized except for the cyclase reaction in which the fifth ring of the chlorophyll molecule is formed during conversion of Mg-protoporphyrin IX monomethyl ester into Protochlorophyllide. The only subunit of the cyclase identified so far, is AcsF (Xantha-l in barley and Chl27 in Arabidopsis). This subunit contains a typical consensus di-iron-binding sequence and belongs to a subgroup of di-iron proteins, such as the plastid terminal oxidase (PTOX) in the chloroplast and the alternative oxidase (AOX) found in mitochondria. In order to complete the catalytic cycle, the irons of these proteins need to be reduced from Fe3+ to Fe2+ and either a reductase or another form of reductant is required. It has been reported that the alternative oxidase (AOX) and the plastid terminal oxidase (PTOX) utilize the di-iron center to oxidise ubiquinol and plastoquinol, respectively. In this paper, we have used a specific inhibitor of di-iron proteins as well as Arabidopsis and barley mutants affected in regulation of photosynthetic electron flow, to show that the cyclase step indeed is directly coupled to the plastoquinone pool. Thus, plastoquinol might act as an electron donor for the cyclase reaction and thereby fulfil the role of a cyclase reductase. That would provide a functional connection between the redox status of the thylakoids and the biosynthesis of chlorophyll.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Plant Physiology and Biochemistry - Volume 97, December 2015, Pages 207-216
نویسندگان
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