Expression of genes for β-glucuronidase and luciferase in three species of japanese conifer (pinus thunbergii, p. densiflora and cryptomeria japonica) after transfer of DNA by microprojectile bombardment

Abstract

Transfer by particle bombardment and expression of genes for β- glucuronidase from Escherichia coli and luciferase from the firefly Photinus pyralis were examined in mature zygotic embryos of three species of Japanese conifer (Pinus thunbergii Pari., Pinus densiflora Sieb, and Cryptomeria japonica D. Don). Successful transfer of DNA was achieved with a Biolistic® particle gun delivery system. The efficient expression of the two genes was confirmed when gold particles of 1.6 μm in diameter were used to bombard zygotic embryos that had been cultured for 4 days, prior to bombardment, on medium that contained Murashige and Skoog's basal salts, Gamborg's B5 vitamins, 3% (w/v) sucrose and 0.3% (w/v) gellan gum. After transfer of DNA under these conditions, high-level expression of both reporter genes was detected in zygotic embryos of P. thunbergii and P. densiflora. However, only high-level expression of the gene for luciferase was detected in C. japonica. These results suggest that both genes can be used as reporter genes for the establishment of reliable procedures for the regeneration of transgenic P. thunbergii and P. densiflora, while only the gene for luciferase can be used as a reporter in the case of C. japonica.