Choisne N, Martin-Canadell A, Small I
Station de Génétique et d'Amélioration des Plantes, INRA, Versailles, France.
Plant J. 1997 Mar;11(3):597-604. doi: 10.1046/j.1365-313x.1997.11030597.x.
The abundance of tRNAs, together with their central role in translation, has generated considerable interest in the use of tRNA genes for biotechnological applications. One such application is the use of suppressor tRNAs to transactive target genes containing premature stop codons. Previous work has shown that such systems can work in transient expression experiments in plant protoplasts; here these experiments are extended to show that suppression of stop codons can occur in whole plants. Transgenic tobacco plants homozygous for a modified tRNA(Leu) gene expressing a strong amber suppressor tRNA, and plants carrying a beta-glucuronidase (gus) gene inactivated by a premature amber stop codon have been obtained. When the two types of plants are crossed, many of the F1 hybrids show significant GUS activity. The GUS activity is dependent on the presence of both the suppressor tRNA gene and the gus gene. Tobacco plants carrying the suppressor tRNA gene are phenotypically normal, fertile and the gene shows normal Menedelian inheritance. The potential applications of such a system are discussed.
tRNA的丰富性及其在翻译中的核心作用，引发了人们对将tRNA基因用于生物技术应用的浓厚兴趣。其中一个应用是利用抑制性tRNA来激活含有提前终止密码子的靶基因。先前的研究表明，此类系统可在植物原生质体的瞬时表达实验中发挥作用；在此，这些实验得到扩展，以表明在整株植物中也可发生终止密码子的抑制。已获得了对表达强琥珀抑制性tRNA的修饰tRNA（Leu）基因纯合的转基因烟草植株，以及携带因提前琥珀终止密码子而失活的β-葡萄糖醛酸酶（gus）基因的植株。当将这两种类型的植株杂交时，许多F1代杂种表现出显著的GUS活性。GUS活性依赖于抑制性tRNA基因和gus基因的同时存在。携带抑制性tRNA基因的烟草植株在表型上正常、可育，且该基因表现出正常的孟德尔遗传。本文讨论了此类系统的潜在应用。
