We have characterized the 5' region of the rice actin 1 gene (Act1) and show that it is an efficient promoter for regulating the constitutive expression of a foreign gene in transgenic rice. By constructing plasmids with 5' regions from the rice Act1 gene fused to the coding sequence of a gene encoding bacterial beta-glucuronidase, we demonstrate that a region 1.3 kilobases upstream of the Act1 translation initiation codon contains all of the 5'-regulatory elements necessary for high-level beta-glucuronidase (GUS) expression in transient assays of transformed rice protoplasts. The rice Act1 primary transcript has a noncoding exon separated by a 5' intron from the first coding exon. Fusions that lack this Act1 intron showed no detectable GUS activity in transient assays of transformed rice protoplasts. Deletion analysis of the Act1 5' intron suggests that the intron-mediated stimulation of GUS expression is associated, in part, with an in vivo requirement for efficient intron splicing.

We have characterized the 5' region of the rice actin 1 gene (Actl) and show that it is an efficient promoter for regulating the constitutive expression of a foreign gene in transgenic rice. By constructing plasmids with 5' regions from the rice Actl gene fused to the coding sequence of a gene encoding bacterial P-glucuronidase, we demonstrate Pthat a region 1.3 kilobases upstream of the Actl translation initiation codon contains all of the 5'-regulatory elements necessary for high-leve1 P-glucuronidase (GUS) expression in transient assays of transformed rice protoplasts. The rice Actl primary transcript has a noncoding exon separated by a 5' intron from the first coding exon. Fusions that lack this Actl intron showed no detectable GUS activity in transient assays of transformed rice protoplasts. Deletion analysis of the Act 7 5' intron suggests that the intron-mediated stimulation of GUS expression is associated, in part, with an in vivo requirement for efficient intron splicing.

The 5' region of the rice actin 1 gene (Actl) has been developed as an efficient regulator of foreign gene expression in transgenic rice plants. To determine the pattern and level of rice Actl 5' region activity, transgenic rice plants containing the Actl 5' region fused to a bacterial 8-glucuronidase (Gus) coding sequence were generated. Two independent clonal lines of transgenic rice plants were analyzed in detail. Quantitative analysis showed that tissue from these transgenic rice plants have a level of GUS protein that represents as much as 3% of total soluble protein.We were able to demonstrate that Actl-Gus gene expression is constitutive throughout the sporophytic and gametophytic tissues of these transgenic rice plants. Plants from one transgenic line were analyzed for the segregation of GUS activity in pollen by in situ histochemical staining, and the inheritance and stability of Actl-Gos expression were assayed in subsequently derived progeny plants.

We describe a comprehensive protocol for large scale production of transgenic Japonica rice plants using non-antibiotic selectable agent, at simplified, cost- and labor-saving manners.

The 5' region of the rice actin 1 gene (Act1) has been developed as an efficient regulator of foreign gene expression in transgenic rice plants. To determine the pattern and level of rice Act1 5' region activity, transgenic rice plants containing the Act1 5' region fused to a bacterial beta-glucuronidase (Gus) coding sequence were generated. Two independent clonal lines of transgenic rice plants were analyzed in detail. Quantitative analysis showed that tissue from these transgenic rice plants have a level of GUS protein that represents as much as 3% of total soluble protein. We were able to demonstrate that Act1-Gus gene expression is constitutive throughout the sporophytic and gametophytic tissues of these transgenic rice plants. Plants from one transgenic line were analyzed for the segregation of GUS activity in pollen by in situ histochemical staining, and the inheritance and stability of Act1-Gus expression were assayed in subsequently derived progeny plants.