title: Enhancement of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production in the transgenic Arabidopsis thaliana by the in vitro evolved highly active mutants of polyhydroxyalkanoate (PHA) synthase from Aeromonas caviae.
abstract: In this study, the enhancement of photosynthetic PHA production was achieved using the highly active mutants of PHA synthase created by the in vitro evolutionally techniques. The wild-type and mutated PHA synthase genes from Aeromonas caviae were introduced into Arabidopsis thaliana together with the NADPH-dependent acetoacetyl-CoA reductase gene from Ralstonia eutropha. Expression of the highly active mutated PHA synthase genes, N149S and D171G, led to an 8-10-fold increase in PHA content in the T1 transgenic Arabidopsis, compared to plants harboring the wild-type PHA synthase gene. In homozygous T2 progenies, PHA content was further increased up to 6.1 mg/g cell dry weight. GC/MS analysis of the purified PHA from the transformants revealed that these PHAs were poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] copolymers consisting of 0.2-0.8 mol % 3HV. The monomer composition of the P(3HB-co-3HV) copolymers synthesized by the wild-type and mutated PHA synthases reflected the substrate specificities observed in Escherichia coli. These results indicate that in vitro evolved PHA synthases can enhance the productivity of PHA and regulate the monomer composition in transgenic plants.
authors: Polymer Chemistry Laboratory, RIKEN Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. mken@riken.jp
authors: Ken'ichiro
authors: K
authors: Matsumoto
authors: Rina
authors: R
authors: Nagao
authors: Takaaki
authors: T
authors: Murata
authors: Yuko
authors: Y
authors: Arai
authors: Tomoyasu
authors: T
authors: Kichise
authors: Hideo
authors: H
authors: Nakashita
authors: Seiichi
authors: S
authors: Taguchi
authors: Hiroaki
authors: H
authors: Shimada
authors: Yoshiharu
authors: Y
authors: Doi
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000333:Aeromonas / Q000201:enzymology*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D009154:Mutation; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D010957:Plasmids; D011091:Polyesters / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
chemical_list: D000217:Acyltransferases; D011091:Polyesters; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C077225:poly(3-hydroxyalkanoic acid) synthase