Expression of an antisense GIGANTEA (GI) gene fragment in transgenic radish causes delayed bolting and flowering
Expression of an antisense GIGANTEA (GI) gene fragment in transgenic radish causes delayed bolting and flowering
复制标题
DOI：
10.1023/a:1015655606996
复制
发表时间：
2002-06-01
影响因子：
3
通讯作者：
Seo, KH
中科院分区：
文献类型：
--
作者：
Curtis, IS;Nam, HG;Seo, KH
利用花浸法表达反义GIGANTEA （GI）基因片段，获得了一株转基因晚花萝卜。将25株植物浸入农杆菌悬浮液中，农杆菌携带来自拟南芥的2.5 kb反义GI基因片段，以及gusA和bar报告基因，均在CaMV 35S启动子的控制下。从这些浸花植株收获的1462个种子中，发现16个抗basta T1植株具有GUS活性（转化效率为1.1%）。南方的分析证实了在这些抗除草剂植物中整合了一个或两个gusA基因拷贝。与野生型植株和pCAMBIA3301（阳性对照）转化植株相比，T1植株中GI基因的表达明显降低。在所分析的11个T1植株（T2代）的后代中，与野生型和阳性对照植株相比，所有品系的抽苔和开花时间均显著延迟，且GI转录物水平与抽苔和开花时间成反比。与野生型相比，抽苔和开花时间最长分别延迟了17天和18天（阳性对照分别延迟了23天和26天）。与野生型和阳性对照植株相比，11个品系中有10个品系的株高显著降低。本研究证明，通过共抑制来下调GI基因可以延缓冷敏长日植物的抽苔。晚花萝卜种质的生产可以延长这一重要作物的种植时间，并为东南亚的饥荒国家提供更多的粮食。
A late-flowering transgenic radish has been produced by the expression of an antisense GIGANTEA (GI) gene fragment using a floral-dip method. Twenty-five plants were dipped into a suspension of Agrobacterium carrying a 2.5 kb antisense GI gene fragment from Arabidopsis, along with the gusA and bar reporter genes, all under the control of a CaMV 35S promoter. From a total of 1462 seeds harvested from these floral-dipped plants, 16 Basta-resistant T1 plants were found to have GUS activity (transformation efficiency of 1.1%). Southern analysis confirmed the integration of one or two copies of the gusA gene in these herbicide-resistant plants. Expression of the GI gene in T1 plants was much reduced compared to both wildtype plants and plants transformed with pCAMBIA3301 (positive control). In the progenies of eleven T1 plants analysed (T2 generation), all lines showed a significant delay in both bolting and flowering times compared to wildtype and positive control plants, and that, the level of GI transcript was inversely proportional to the time of bolting and flowering. At a maximum, bolting and flowering times were delayed by 17 and 18 days respectively, compared to wildtype plants (in positive control plants, the delay was 23 and 26 days, respectively). Ten of the 11 lines exhibited a significant reduction in plant height compared to wildtype and positive control plants. This study provides evidence that down-regulation of the GI gene by co-suppression could delay bolting in a cold-sensitive long-day (LD) plant. Production of late-flowering germplasms of radish may allow this important crop to be cultivated over an extended period and also provide further food to the famine countries of S/E Asia.