Thorsness M K, Kandasamy M K, Nasrallah M E, Nasrallah J B
Section of Plant Biology, Cornell University, Ithaca, New York 14853.
Dev Biol. 1991 Jan;143(1):173-84. doi: 10.1016/0012-1606(91)90064-a.
The S-locus glycoprotein gene of Brassica is derived from the genetic locus that controls the self-incompatibility response and the specific recognition between pollen and stigma. The promoter of this gene was used to direct expression of the diphtheria toxin A chain gene and the Escherichia coli beta-glucuronidase gene in transgenic Nicotiana tabacum. Expression of the promoter in cells of the pistil and in pollen suggests that a single gene may direct the self-incompatibility response in the two interacting cell types. Additionally, the fusion genes were expressed gametophytically in the heterologous host species, Nicotiana, rather than sporophytically as expected for Brassica. Thus, although the genes involved in self-incompatibility in Brassica and Nicotiana are not homologous in their coding regions, signals for expression of these genes are apparently conserved between the two genera. Our analysis of toxic gene fusion transformants shows that genetic ablation is useful for probing developmental processes and for studying temporal and spatial patterns of gene expression in plants.
芸苔属植物的S-位点糖蛋白基因源自控制自交不亲和反应以及花粉与柱头之间特异性识别的遗传位点。该基因的启动子被用于指导白喉毒素A链基因和大肠杆菌β-葡萄糖醛酸酶基因在转基因烟草中的表达。该启动子在雌蕊细胞和花粉中的表达表明，单个基因可能在两种相互作用的细胞类型中指导自交不亲和反应。此外，融合基因在异源宿主物种烟草中以配子体方式表达，而不是像芸苔属植物预期的那样以孢子体方式表达。因此，尽管芸苔属植物和烟草中参与自交不亲和的基因在编码区域并不同源，但这些基因的表达信号在这两个属之间显然是保守的。我们对毒性基因融合转化体的分析表明，基因消融对于探究植物发育过程以及研究基因表达的时空模式是有用的。
