Open AccessCriteria for high‐level expression of a fungal laccase gene in transgenic maize
Author(s) -
Hood Elizabeth E.,
Bailey Michele R.,
Beifuss Katherine,
MagallanesLundback Maria,
Horn Michael E.,
Callaway Evelyn,
Drees Carol,
Delaney Donna E.,
Clough Richard,
Howard John A.
Publication year - 2003
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1046/j.1467-7652.2003.00014.x
Subject(s) - biology , transgene , germplasm , gene , gene expression , germination , embryo , genetically modified crops , agrobacterium , transformation (genetics) , botany , microbiology and biotechnology , genetics
Summary Expression of industrial enzymes in transgenic plants offers an alternative system to fungal fermentation for large‐scale production. Very high levels of expression are required to make the enzymes cost‐effective. We tested several parameters to determine the best method for achieving high levels of expression for a fungal laccase gene. Transgenic maize plants were generated using an Agrobacterium ‐mediated system. The molecular parameters that induced the highest expression were the maize embryo‐preferred globulin 1 promoter and targeting of the protein to the cell wall. Two independent transgenic events that yielded multiple clonal plants were characterized in detail. Independent transgenic events 01 and 03 contained two or one copies of T‐DNA, respectively. Plants derived from a single transgenic event varied in expression level, and the variation in expression levels was heritable. Within the seed, expression in these plants was primarily within the embryo, and was associated with seed browning and limited germination. High oil germplasm was used to increase germination, as well as to assist in increasing expression 20‐fold in five generations through breeding and selection.