College of Horticulture, South China Agriculture University, Guangzhou City, Guanghdong P.R. China.
Genet Mol Biol. 2010 Apr;33(2):298-307. doi: 10.1590/S1415-47572010005000043. Epub 2010 Jun 1.
This study was designed to control plant fertility by cell lethal gene Barnase expressing at specific developmental stage and in specific tissue of male organ under the control of Cre/loxP system, for heterosis breeding, producing hybrid seed of eggplant. The Barnase-coding region was flanked by loxP recognition sites for Cre-recombinase. The eggplant inbred/pure line ('E-38') was transformed with Cre gene and the inbred/pure line ('E-8') was transformed with the Barnase gene situated between loxp. The experiments were done separately, by means of Agrobacterium co-culture. Four T(0) -plants with the Barnase gene were obtained, all proved to be male-sterile and incapable of producing viable pollen. Flowers stamens were shorter, but the vegetative phenotype was similar to wild-type. Five T (0) -plants with the Cre gene developed well, blossomed out and set fruit normally. The crossing of male-sterile Barnase-plants with Cre expression transgenic eggplants resulted in site-specific excision with the male-sterile plants producing normal fruits. With the Barnase was excised, pollen fertility was fully restored in the hybrids. The phenotype of these restored plants was the same as that of the wild-type. Thus, the Barnase and Cre genes were capable of stable inheritance and expression in progenies of transgenic plants.
本研究旨在通过细胞致死基因 Barnase 在特定发育阶段和雄性器官的特定组织中表达，控制植物的育性，在 Cre/loxP 系统的控制下，进行杂种优势育种，生产茄子杂种种子。Barnase 编码区两侧为 Cre 重组酶的 loxP 识别位点。用 Cre 基因转化茄子自交系/纯系（'E-38'），用 Barnase 基因转化位于 loxp 之间的自交系/纯系（'E-8'）。通过农杆菌共培养分别进行实验。获得了 4 株带有 Barnase 基因的 T(0) -植物，所有这些植物都被证明是雄性不育的，无法产生有活力的花粉。花的雄蕊较短，但营养表型与野生型相似。带有 Cre 基因的 5 株 T(0) -植物生长良好，开花结果正常。雄性不育 Barnase-植物与 Cre 表达转基因茄子的杂交导致雄性不育植物产生正常果实的特异性切除。当 Barnase 被切除后，杂种的花粉育性得到完全恢复。这些恢复植物的表型与野生型相同。因此，Barnase 和 Cre 基因能够在转基因植物后代中稳定遗传和表达。
