Vieweg Martin F, Frühling Martin, Quandt Hans-Joachim, Heim Ute, Bäumlein Helmut, Pühler Alfred, Küster Helge, Andreas M Perlick
Universität Bielefeld, Fakultät für Biologie, Lehrstuhl für Genetik, P. O. Box 100131, D-33501 Bielefeld, Germany.
Mol Plant Microbe Interact. 2004 Jan;17(1):62-9. doi: 10.1094/MPMI.2004.17.1.62.
The VfLb29 leghemoglobin gene promoter was polymerase chain reaction-amplified from a Vicia faba genomic library and was fused to the gusAint coding region. Expression of the chimeric gene was analyzed in transgenic hairy roots of the legumes V. faba, V. hirsuta, and Medicago truncatula as well as in transgenic Nicotiana tabacum plants. The VfLb29 promoter was found to be specifically active not only in the infected cells of the nitrogen-fixing zone of root nodules but also in arbuscule-containing cells of transgenic V. faba and M. truncatula roots colonized by the endomycorrhizal fungus Glomus intraradices. In addition to these two legumes, specific expression in arbuscule-containing cells was also observed in the nonlegume N. tabacum. All studies were done in comparison to the V. faba leghemoglobin gene promoter VfLb3 that as VfLb29 was expressed in the infected cells of root nodules but showed no activity in endomycorrhiza. An activation of the VfLb29 promoter due to hypoxia in metabolically active tissues was excluded. The conserved activation in arbuscule-containing cells of legumes and the nonlegume N. tabacum suggests a conserved trigger for this promoter in legume and nonlegume endomycorrhiza symbioses.
从蚕豆基因组文库中通过聚合酶链反应扩增出VfLb29豆血红蛋白基因启动子，并将其与gusAint编码区融合。在豆科植物蚕豆、硬毛蚕豆和蒺藜苜蓿的转基因毛状根以及转基因烟草植株中分析了嵌合基因的表达。发现VfLb29启动子不仅在根瘤固氮区的受感染细胞中具有特异性活性，而且在被根内球囊霉定殖的转基因蚕豆和蒺藜苜蓿根的含丛枝细胞中也具有特异性活性。除了这两种豆科植物外，在非豆科植物烟草的含丛枝细胞中也观察到了特异性表达。所有研究均与蚕豆豆血红蛋白基因启动子VfLb3进行比较，VfLb3与VfLb29一样在根瘤的受感染细胞中表达，但在菌根中无活性。排除了代谢活跃组织中缺氧导致VfLb29启动子激活的可能性。豆科植物和非豆科植物烟草含丛枝细胞中的保守激活表明，在豆科植物和非豆科植物菌根共生中，该启动子存在保守的触发因素。
