The promoter of the Vicia faba L. leghemoglobin gene VfLb29 is specifically activated in the infected cells of root nodules and in the arbuscule-containing cells of mycorrhizal roots from different legume and nonlegume plants.
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.
Vieweg
Martin F
MF
Universität Bielefeld, Fakultät für Biologie, Lehrstuhl für Genetik, P. O. Box 100131, D-33501 Bielefeld, Germany.
Frühling
Martin
M
Quandt
Hans-Joachim
HJ
Heim
Ute
U
Bäumlein
Helmut
H
Pühler
Alfred
A
Küster
Helge
H
Andreas
M Perlick
MP
D000693:Anaerobiosis; D001483:Base Sequence; D007887:Fabaceae / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology; D015966:Gene Expression Regulation, Fungal; D018506:Gene Expression Regulation, Plant; D007874:Leghemoglobin / Q000235:genetics* / Q000378:metabolism; D029902:Medicago / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000254:growth & development*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013559:Symbiosis / Q000235:genetics* / Q000502:physiology; D014026:Nicotiana / Q000235:genetics* / Q000254:growth & development / Q000382:microbiology; D031307:Vicia faba / Q000235:genetics / Q000254:growth & development / Q000382:microbiology
D007874:Leghemoglobin; D010940:Plant Proteins