cg12 expression is specifically linked to infection of root hairs and cortical cells during Casuarina glauca and Allocasuarina verticillata actinorhizal nodule development.
cg12 is an early actinorhizal nodulin gene from Casuarina glauca encoding a subtilisin-like serine protease. Using transgenic Casuarinaceae plants carrying cg12-gus and cg12-gfp fusions, we have studied the expression pattern conferred by the cg12 promoter region after inoculation with Frankia. cg12 was found to be expressed in root hairs and in root and nodule cortical cells containing Frankia infection threads. cg12 expression was also monitored after inoculation with ineffective Frankia strains, during mycorrhizae formation, and after diverse hormonal treatments. None of these treatments was able to induce its expression, therefore suggesting that cg12 expression is linked to plant cell infection by Frankia strains. Possible roles of cg12 in actinorhizal symbiosis are discussed.
Svistoonoff
Sergio
S
Equipe Rhizogenèse, UMR 1098, Institut de Recherche pour le Développement, BP 64501, 34394 Montpellier cedex 5, France.
Laplaze
Laurent
L
Auguy
Florence
F
Runions
John
J
Duponnois
Robin
R
Haseloff
Jim
J
Franche
Claudine
C
Bogusz
Didier
D
D017360:Arabidopsis; D001483:Base Sequence; D040161:Frankia / Q000145:classification / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter / Q000235:genetics; D019684:Magnoliopsida / Q000166:cytology / Q000235:genetics* / Q000382:microbiology*; D008969:Molecular Sequence Data; D010940:Plant Proteins; D018517:Plant Roots / Q000166:cytology / Q000235:genetics* / Q000382:microbiology*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D013381:Subtilisins / Q000737:chemistry / Q000235:genetics*; D013559:Symbiosis / Q000502:physiology
D010940:Plant Proteins; D013381:Subtilisins