Researchers from Arkansas State University and partners tested three
endosperm promoters for expression of a cellulase gene. The results are
reported in Transgenic Research.

Expression of recombinant proteins in plants is used in the development of
vaccines, pharmaceuticals, and industrial enzymes. In a previous study, the
researchers produced recombinant proteins in maize kernels using only the
embryo, which drives the expression of foreign genes with a maize promoter.
This has resulted in strong expression, but only 10-12% of the seed tissue
were used. To increase the amount of recombinant protein to be recovered
from a specific amount of biomass, the researchers tested three endosperm
promoters (2 rice promoters and maize á-zein promoter) in two tandem
expression constructs. Results showed that although the rice promoters
produced stable amounts of cellulase, the maize promoter was the most
effective. Analysis confirmed that the expression only occurred in the
endosperm.



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