Figure 6.

Involvement of the elements in the 5′-UTR of Esi47 in the regulation of its expression. Maize callus tissues were bombarded with DNA constructs as indicated. Esi47-Act1-GUS is the fusion of the 3-kb Esi47 fragment immediately upstream of the translation initiation of the protein kinase ORF with the 5′-UTR intron from the rice actin-1 gene Act1 and the reporter gene for GUS. Esi47^ΔI-1-Act1-GUS is the same as Esi47-Act1-GUS except the 5′-UTR of Esi47 has been removed. In Esi47^ΔuORF-Act1-GUS the ATG codon of the uORF of Esi47 has been corrupted, and in Esi47^{ΔI-1, ΔuORF}-Act1-GUS both the 5′-UTR intron has been removed and the uORF has been corrupted. After DNA delivery the callus tissues were treated with 20 μm ABA for 48 h as indicated; tissues for control were not treated. GUS activities were measured and normalized against the luciferase activities cobombarded to the callus. The values are averages of four independent shootings except for the construct Esi47-Act1-GUS with which eight shootings were carried out. The sds are shown as error bars.