title: Elevation of oil body integrity and emulsion stability by polyoleosins, multiple oleosin units joined in tandem head-to-tail fusions.
abstract: We have successfully created polyoleosins by joining multiple oleosin units in tandem head-to-tail fusions. Constructs encoding recombinant proteins of 1, 3 and 6 oleosin repeats were purposely expressed both in planta and in Escherichia coli. Recombinant polyoleosins accumulated in the seed oil bodies of transgenic plants and in the inclusion bodies of E. coli. Although polyoleosin was estimated to only accumulate to <2% of the total oil body protein in planta, their presence increased the freezing tolerance of imbibed seeds as well as emulsion stability and structural integrity of purified oil bodies; these increases were greater with increasing oleosin repeat number. Interestingly, the hexameric form of polyoleosin also led to an observable delay in germination which could be overcome with the addition of external sucrose. Prokaryotically produced polyoleosin was purified and used to generate artificial oil bodies and the increase in structural integrity of artificial oil bodies-containing polyoleosin was found to mimic those produced in planta. We describe here the construction of polyoleosins, their purification from E. coli, and properties imparted on seeds as well as native and artificial oil bodies. A putative mechanism to account for these properties is also proposed.
authors.affiliation: AgResearch Limited, Forage Biotechnology, Tennent Drive, Palmerston North, New Zealand.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Scott
authors.forename: Somrutai
authors.initials: S
authors.lastname: Winichayakul
authors.forename: Marissa
authors.initials: M
authors.lastname: Roldan
authors.forename: Ruth
authors.initials: R
authors.lastname: Cookson
authors.forename: Melanie
authors.initials: M
authors.lastname: Willingham
authors.forename: Maria
authors.initials: M
authors.lastname: Castle
authors.forename: Ringo
authors.initials: R
authors.lastname: Pueschel
authors.forename: Chi-Chung
authors.initials: CC
authors.lastname: Peng
authors.forename: Jason T C
authors.initials: JT
authors.lastname: Tzen
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Roberts
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D002479:Inclusion Bodies / Q000378:metabolism*; D010938:Plant Oils / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D031685:Sesamum / Q000235:genetics / Q000378:metabolism
chemical_list: D010938:Plant Oils; D010940:Plant Proteins