Science. 1986 Mar 14;231(4743):1294-7. doi: 10.1126/science.231.4743.1294.
Brome mosaic virus (BMV) is a plant virus whose genome consists of three RNA components. A previously described viral complementary DNA expression system has been used to express both wild-type and altered genomic RNA's in barley protoplasts. Variants of BMV RNA3 were constructed in which the coat gene had been removed or replaced with sequences encoding chloramphenicol acetyltransferase (CAT). CAT sequences were also inserted near the 5' end of the intact coat gene. When inoculated on protoplasts together with transcripts of BMV RNA's 1 and 2, all of these RNA3 derivatives were replicated and produced subgenomic RNA's analogous to the normal subgenomic coat protein messenger RNA. RNA3 derivatives in which the CAT coding sequences were oriented with the same polarity as viral genes produced significant CAT activity in protoplasts. CAT expression was improved by inserting the CAT gene in frame with the upstream coat protein initiation codon, and exceeded expression in plant cells transformed with Ti plasmid-based vectors.
雀麦花叶病毒（BMV）是一种植物病毒，其基因组由三个 RNA 成分组成。以前描述的病毒互补 DNA 表达系统已被用于在大麦原生质体中表达野生型和改变的基因组 RNA。构建了 BMV RNA3 的变体，其中外壳基因已被去除或被编码氯霉素乙酰转移酶（CAT）的序列取代。CAT 序列也被插入完整外壳基因的 5'端附近。当与 BMV RNA 的 1 和 2 的转录本一起接种在原生质体上时，所有这些 RNA3 衍生物都被复制，并产生类似于正常亚基因组外壳蛋白信使 RNA 的亚基因组 RNA。CAT 编码序列与病毒基因具有相同极性的 RNA3 衍生物在原生质体中产生显著的 CAT 活性。通过将 CAT 基因与上游外壳蛋白起始密码子框内插入，可提高 CAT 表达，并超过 Ti 质粒载体转化的植物细胞中的表达。
