Elevation of oil body integrity and emulsion stability by polyoleosins, multiple oleosin units joined in tandem head-to-tail fusions.
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.
Scott
Richard W
RW
AgResearch Limited, Forage Biotechnology, Tennent Drive, Palmerston North, New Zealand.
Winichayakul
Somrutai
S
Roldan
Marissa
M
Cookson
Ruth
R
Willingham
Melanie
M
Castle
Maria
M
Pueschel
Ringo
R
Peng
Chi-Chung
CC
Tzen
Jason T C
JT
Roberts
Nicholas J
NJ
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
D010938:Plant Oils; D010940:Plant Proteins