RESUMEN
We have compared the level of expression of the Cauliflower Mosaic Virus 35S promoter and the nopaline synthase promoter when fused to a common reporter gene. A cassette containing the neomycin phosphotransferase (type II) coding sequence followed by the nopaline synthase 3' nontranslated region was used for transcriptional and translational evaluation of the two different promoters. These chimeric genes were introduced into petunia plants and the copy number of the gene, the steady state level of NPTII transcript and the levels of NPTII enzyme activity were determined. In this paper, we report that the NPT II transcript levels are on the average 30 fold higher in plants containing CaMV 35S promoter and leader sequences than in plants containing the same reporter gene but nopaline synthase promoter and leader sequences. Similarly, plants containing the CaMV 35S promoter had an average of 110 fold higher levels of NPTII enzyme activity than those containing the nopaline synthase promoter. The significance of these results for expression of foreign genes in plants is discussed. In addition, we describe the construction of a convenient plant expression cassette vector (pMON316) which utilizes the CaMV 35S promoter.
Asunto(s)
Aminoácido Oxidorreductasas/genética , Genes Virales , Genes , Virus del Mosaico/genética , Plantas/genética , Regiones Promotoras Genéticas , Secuencia de Bases , Brassica , Enzimas de Restricción del ADN , Kanamicina Quinasa , Hibridación de Ácido Nucleico , Fosfotransferasas/genética , Plantas/enzimologíaRESUMEN
Transformed Arabidopsis thaliana plants have been produced by a modified leaf disk transformation-regeneration method. Leaf pieces from sterilely grown plants were precultured for 2 days and inoculated with an Agrobacterium tumefaciens strain containing an avirulent Ti (tumor-inducing) plasmid with a chimeric gene encoding hygromycin resistance. After cocultivation for 2 days, the leaf pieces were placed on a medium that selects for hygromycin resistance. Shoots regenerated within 3 months and were excised, rooted, and transferred to soil. Transformation was confirmed by opine production, hygromycin resistance, and DNA blot hybridization of both primary transformants and progeny. This process for producing transgenic Arabidopsis plants should enhance the usefulness of the species for experimental biology.