I. Diaz et al., THE PROMOTER OF BARLEY TRYPSIN-INHIBITOR BTI-CME, DISCRIMINATES BETWEEN WHEAT AND BARLEY ENDOSPERM PROTOPLASTS IN TRANSIENT EXPRESSION ASSAYS, Plant cell reports, 12(12), 1993, pp. 698-701
Several promoter fragments from the barley gene coding for trypsin inh
ibitor, BTI-CMe, have been fused to the beta-glucuronidase (GUS) repor
ter gene and these chimeric constructs used for transient expression i
n protoplasts. Transfection of developing endosperm protoplasts from b
arley (cv Bomi) show a maximum GUS expression of about 50% of that dri
ven by the cauliflower mosaic virus 35S promoter, while in wheat endos
perm protoplasts expression is less than 10%. No significant expressio
n is found in transfected leaf protoplasts from barley, wheat or tobac
co (<2% of the 35S control). All the information required for endosper
m and barley specificity is present in the 343 bp proximal to the tran
slation initiation site.