TY - JOUR

T1 - Composite medicago truncatula plants harbouring agrobacterium rhizogenes-transformed roots reveal normal mycorrhization by glomus intraradices

AU - Mrosk, Cornelia

AU - Forner, Susanne

AU - Hause, Gerd

AU - Küster, Helge

AU - Kopka, Joachim

AU - Hause, Bettina

N1 - Funding information: The work was carried out in frame of the MolMyk programme funded by the German research foundation (DFG SPP 1084). HK acknowledges financial support from the International Graduate School in Bioinformatics and Genome Research (Bielefeld University).

PY - 2009/9/1

Y1 - 2009/9/1

N2 - Composite plants consisting of a wild-type shoot and a transgenic root are frequently used for functional genomics in legume research. Although transformation of roots using Agrobacterium rhizogenes leads to morphologically normal roots, the question arises as to whether such roots interact with arbuscular mycorrhizal (AM) fungi in the same way as wild-type roots. To address this question, roots transformed with a vector containing the fluorescence marker DsRed were used to analyse AM in terms of mycorrhization rate, morphology of fungal and plant subcellular structures, as well as transcript and secondary metabolite accumulations. Mycorrhization rate, appearance, and developmental stages of arbuscules were identical in both types of roots. Using Mt16kOLI1Plus microarrays, transcript profiling of mycorrhizal roots showed that 222 and 73 genes exhibited at least a 2-fold induction and less than half of the expression, respectively, most of them described as AM regulated in the same direction in wild-type roots. To verify this, typical AM marker genes were analysed by quantitative reverse transcription-PCR and revealed equal transcript accumulation in transgenic and wild-type roots. Regarding secondary metabolites, several isoflavonoids and apocarotenoids, all known to accumulate in mycorrhizal wild-type roots, have been found to be up-regulated in mycorrhizal in comparison with non-mycorrhizal transgenic roots. This set of data revealed a substantial similarity in mycorrhization of transgenic and wild-type roots of Medicago truncatula, validating the use of composite plants for studying AM-related effects.

AB - Composite plants consisting of a wild-type shoot and a transgenic root are frequently used for functional genomics in legume research. Although transformation of roots using Agrobacterium rhizogenes leads to morphologically normal roots, the question arises as to whether such roots interact with arbuscular mycorrhizal (AM) fungi in the same way as wild-type roots. To address this question, roots transformed with a vector containing the fluorescence marker DsRed were used to analyse AM in terms of mycorrhization rate, morphology of fungal and plant subcellular structures, as well as transcript and secondary metabolite accumulations. Mycorrhization rate, appearance, and developmental stages of arbuscules were identical in both types of roots. Using Mt16kOLI1Plus microarrays, transcript profiling of mycorrhizal roots showed that 222 and 73 genes exhibited at least a 2-fold induction and less than half of the expression, respectively, most of them described as AM regulated in the same direction in wild-type roots. To verify this, typical AM marker genes were analysed by quantitative reverse transcription-PCR and revealed equal transcript accumulation in transgenic and wild-type roots. Regarding secondary metabolites, several isoflavonoids and apocarotenoids, all known to accumulate in mycorrhizal wild-type roots, have been found to be up-regulated in mycorrhizal in comparison with non-mycorrhizal transgenic roots. This set of data revealed a substantial similarity in mycorrhization of transgenic and wild-type roots of Medicago truncatula, validating the use of composite plants for studying AM-related effects.

KW - Agrobacterium rhizogenes

KW - Arbuscular mycorrhiza

KW - Composite plants

KW - Glomus intraradices

KW - Isoflavanoids

KW - Transcript profiling

KW - Transmission electron microscopy

UR - http://www.scopus.com/inward/record.url?scp=69949173238&partnerID=8YFLogxK

U2 - 10.1093/jxb/erp220

DO - 10.1093/jxb/erp220

M3 - Article

C2 - 19574251

AN - SCOPUS:69949173238

VL - 60

SP - 3797

EP - 3807

JO - Journal of experimental botany

JF - Journal of experimental botany

SN - 0022-0957

IS - 13

ER -