Shen W H, Ramos C, Hohn B
Friedrich Miescher Institut, Basel, Switzerland.
Plant Mol Biol. 1998 Feb;36(3):387-92. doi: 10.1023/a:1005963430366.
We have previously established a reverse genetic system for studying excision of the transposable element Ds1 in maize plants. Ds1 carried by the genome of maize streak virus (MSV) is introduced into maize plants by agroinfection. Excision of Ds1 from the MSV genome depends on the presence of an active Ac element in the recipient maize plants. With the purpose of exploiting MSV-Ds1 as vector for maize transformation, we studied different genes encoding the transposase (TPase) for their efficiency of activating Ds1 excision. These genes were inserted in the same T-DNA carrying MSV-Ds1 and introduced into maize plants by Agrobacterium-mediated transformation. We showed that the wild-type TPase transcribed by the 2' promoter produced much higher efficiency of Ds1 excision than that transcribed by the Ac promoter. In contrast to what had been observed in tobacco and petunia, the truncated TPase (103-807) lacking the amino-terminal 102 amino acids gave a much more reduced Ds1 excision efficiency than the wild-type TPase when both genes were transcribed by the 2' promoter.
我们之前建立了一个反向遗传系统，用于研究玉米植株中转座元件Ds1的切除。玉米条纹病毒（MSV）基因组携带的Ds1通过农杆菌感染被导入玉米植株。Ds1从MSV基因组中的切除取决于受体玉米植株中活性Ac元件的存在。为了将MSV-Ds1用作玉米转化的载体，我们研究了不同的转座酶（TPase）编码基因激活Ds1切除的效率。这些基因被插入携带MSV-Ds1的同一T-DNA中，并通过农杆菌介导的转化导入玉米植株。我们发现，由2'启动子转录的野生型TPase产生的Ds1切除效率比由Ac启动子转录的效率高得多。与在烟草和矮牵牛中观察到的情况相反，当两个基因都由2'启动子转录时，缺少氨基末端102个氨基酸的截短型TPase（103-807）的Ds1切除效率比野生型TPase低得多。
