TY - JOUR

T1 - Identification and expression regulation of symbiotically activated legume genes

AU - Küster, Helge

AU - Vieweg, Martin F.

AU - Manthey, Katja

AU - Baier, Markus C.

AU - Hohnjec, Natalija

AU - Perlick, Andreas M.

N1 - Funding information: This work was supported by the Deutsche Forschungsgemeinschaft in projects Pe-814/1-1, Pe-814/1-2 and KU1478/2-3 (all SPP 1084 ”Mykorrhiza”). Helge Küster and Natalija Hohnjec acknowledge financial support by the International Graduate School in Bioinformatics and Genome Research (Center for Biotechnology, Bielefeld University). We are grateful to our Diploma students Esther M.N. Dohmann and Vera Fehlberg for their contribution to the VfLb29 promoter analysis and we thank Manuela Meyer and Tanja Thias (Institute for Genome Research, Center for Biotechnology, Universität Bielefeld) for excellent technical support.

PY - 2007/1/1

Y1 - 2007/1/1

N2 - Legume plants are able to enter two different endosymbioses with soil prokaryotes and soil fungi, leading to nitrogen-fixing root nodules and to arbuscular mycorrhiza (AM), respectively. We applied in silicoand microarray-based transcriptome profiling approaches to uncover the transcriptome of developing root nodules and AM roots of the model legume Medicago truncatula. Several hundred genes were found to be activated in different stages of either symbiosis, with almost 100 genes being co-induced during nodulation and in arbuscular mycorrhiza. These co-induced genes can be associated with different cellular functions required for symbiotic efficiency, such as the facilitation of transport processes across the perisymbiotic membranes that surround the endosymbiotic bacteroids in root nodules and the arbuscules in AM roots. To specify promoter elements required for gene expression in arbuscule-containing cells, reporter gene fusions of the promoter of the Vicia faba leghemoglobin gene VfLb29 were studied by loss-of-function and gain-of-function approaches in transgenic hairy roots. These analyses specified a 85-bp fragment that was necessary for gene expression in arbuscule-containing cells but was dispensible for gene activation in root nodules. In contrast to promoters mediating gene expression in the infected cells of root nodules, the activation of genes in AM appears to be governed by more complex regulatory systems requiring different promoter modules.

AB - Legume plants are able to enter two different endosymbioses with soil prokaryotes and soil fungi, leading to nitrogen-fixing root nodules and to arbuscular mycorrhiza (AM), respectively. We applied in silicoand microarray-based transcriptome profiling approaches to uncover the transcriptome of developing root nodules and AM roots of the model legume Medicago truncatula. Several hundred genes were found to be activated in different stages of either symbiosis, with almost 100 genes being co-induced during nodulation and in arbuscular mycorrhiza. These co-induced genes can be associated with different cellular functions required for symbiotic efficiency, such as the facilitation of transport processes across the perisymbiotic membranes that surround the endosymbiotic bacteroids in root nodules and the arbuscules in AM roots. To specify promoter elements required for gene expression in arbuscule-containing cells, reporter gene fusions of the promoter of the Vicia faba leghemoglobin gene VfLb29 were studied by loss-of-function and gain-of-function approaches in transgenic hairy roots. These analyses specified a 85-bp fragment that was necessary for gene expression in arbuscule-containing cells but was dispensible for gene activation in root nodules. In contrast to promoters mediating gene expression in the infected cells of root nodules, the activation of genes in AM appears to be governed by more complex regulatory systems requiring different promoter modules.

KW - Arbuscular mycorrhiza

KW - In Silico transcriptome profiling

KW - Medicago truncatula

KW - Microarray-based expression profiling

KW - Promoter analysis

KW - Root nodule

KW - Symbiosin genes

KW - Transgenic hairy roots

KW - Vicia faba

UR - http://www.scopus.com/inward/record.url?scp=33845563511&partnerID=8YFLogxK

U2 - 10.1016/j.phytochem.2006.09.029

DO - 10.1016/j.phytochem.2006.09.029

M3 - Review article

C2 - 17081575

AN - SCOPUS:33845563511

VL - 68

SP - 8

EP - 18

JO - PHYTOCHEMISTRY

JF - PHYTOCHEMISTRY

SN - 0031-9422

IS - 1

ER -