PLANT PHYSIOLOGY , Vol 101, Issue 3 1097-1101, Copyright © 1993 by American Society of Plant Biologists
Expression of the Acc1 Gene-Encoded Acetyl-Coenzyme A Carboxylase in Developing Maize (Zea mays L.) Kernels
D. A. Somers, R. A. Keith, M. A. Egli, L. C. Marshall, B. G. Gengenbach, J. W. Gronwald and D. L. Wyse
Department of Agronomy and Plant Genetics (D.A.S., R.A.K., M.A.E., L.C.M., B.G.G., D.L.W.), and Plant Molecular Genetics Institute (D.A.S., B.G.G.), University of Minnesota, and Plant Science Research Unit, United States Department of Agriculture, Agricultural Research Service (J.W.G.), St. Paul, Minnesota 55108
A mutation (Acc1-S2) in the structural gene for maize (Zea mays L.)
acetyl-coenzyme A carboxylase (ACCase) that significantly reduces
sethoxydim inhibition of leaf ACCase activity was used to investigate the
gene-enzyme relationship regulating ACCase activity during oil deposition
in developing kernels. Mutant embryo and endosperm ACCase activities were
more than 600-fold less sensitive to sethoxydim inhibition than ACCase in
wild-type kernel tissues. Moreover, in vitro cultured mutant kernels
developed normally in the presence of sethoxydim concentrations that
inhibited wild-type kernel development. The results indicate that the
Acc1-encoded ACCase accounts for the majority of ACCase activity in
developing maize kernels, suggesting that Acc1-encoded ACCase functions not
only during membrane biogenesis in leaves but is also the predominant form
of ACCase involved in storage lipid biosynthesis in maize embryos.
