title: One divinyl reductase reduces the 8-vinyl groups in various intermediates of chlorophyll biosynthesis in a given higher plant species, but the isozyme differs between species.
abstract: Divinyl reductase (DVR) converts 8-vinyl groups on various chlorophyll intermediates to ethyl groups, which is indispensable for chlorophyll biosynthesis. To date, five DVR activities have been detected, but adequate evidence of enzymatic assays using purified or recombinant DVR proteins has not been demonstrated, and it is unclear whether one or multiple enzymes catalyze these activities. In this study, we systematically carried out enzymatic assays using four recombinant DVR proteins and five divinyl substrates and then investigated the in vivo accumulation of various chlorophyll intermediates in rice (Oryza sativa), maize (Zea mays), and cucumber (Cucumis sativus). The results demonstrated that both rice and maize DVR proteins can convert all of the five divinyl substrates to corresponding monovinyl compounds, while both cucumber and Arabidopsis (Arabidopsis thaliana) DVR proteins can convert three of them. Meanwhile, the OsDVR (Os03g22780)-inactivated 824ys mutant of rice exclusively accumulated divinyl chlorophylls in its various organs during different developmental stages. Collectively, we conclude that a single DVR with broad substrate specificity is responsible for reducing the 8-vinyl groups of various chlorophyll intermediates in higher plants, but DVR proteins from different species have diverse and differing substrate preferences, although they are homologous.
authors.affiliation: Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Pingrong
authors.initials: P
authors.lastname: Wang
authors.forename: Chunmei
authors.initials: C
authors.lastname: Wan
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Xu
authors.forename: Pingyu
authors.initials: P
authors.lastname: Wang
authors.forename: Wenming
authors.initials: W
authors.lastname: Wang
authors.forename: Changhui
authors.initials: C
authors.lastname: Sun
authors.forename: Xiaozhi
authors.initials: X
authors.lastname: Ma
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Xiao
authors.forename: Jianqing
authors.initials: J
authors.lastname: Zhu
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Gao
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Deng
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002734:Chlorophyll / Q000096:biosynthesis*; D003001:Cloning, Molecular; D028462:Cucumis / Q000201:enzymology* / Q000235:genetics; D004789:Enzyme Activation; D057075:Enzyme Assays; D017343:Genes, Plant; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D016366:Open Reading Frames; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010088:Oxidoreductases / Q000378:metabolism*; D011521:Protochlorophyllide / Q000378:metabolism; D011524:Protoporphyrins / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013379:Substrate Specificity; D003313:Zea mays / Q000201:enzymology* / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D007527:Isoenzymes; D011524:Protoporphyrins; D011994:Recombinant Proteins; D002734:Chlorophyll; D011521:Protochlorophyllide; C028025:protoporphyrin IX; D010088:Oxidoreductases; C504787:divinyl reductase; Arabidopsis