LIU, JINYUAN1*, GABRIELLA ENDRE2, JENNIFER CHO3, CHRISTOPHER D TOWN3, KATHRYN A VANDENBOSCH2, and MARIA J HARRISON1. 1The Samuel Roberts Noble Foundation, OK73402,USA; 2University of Minnesota, MN55108,USA; 3The Institute for Genomic Research, MD 20850,USA. - Profiling of genes expressed in Medicago truncatula / Glomus versiforme arbuscular mycorrhizal roots.
In natural ecosystems, the roots of most vascular plants exist in
symbiotic association with arbuscular mycorrhizal (AM) fungi. These
are mutually beneficial associations, in which the plants provides
carbon to the fungus while the fungus assists the plant with the
acquisition of phosphate and other mineral nutrients from the
environment. To gain a better understanding at molecular level of the
development, functioning and regulation of the AM symbiosis, a cDNA
library was prepared from Medicago truncatula roots colonized
with the arbuscular mycorrhizal fungus, Glomus versiforme . EST
sequencing of the clones from the library has been conducted and 7351
ESTs from the library have been annotated by TIGR and deposited at
NCBI. Preliminary clustering analyses performed by TIGR, indicates
that 93 tentative contigs (TC) of ESTs are unique to the M.
truncatula /G. versiforme library and 4421 tentative
uni-genes were also identified in this library. The temporal
expression profiles of 2228 uni-gene during development of the
mycorrhiza have been conducted using macro-arrays. The arrays were
hybridized with 33P labeled first-strand cDNA probes prepared from
M. truncatula / G. versiforme roots and mock-inoculated
M. truncatula roots. A set of genes showing significantly
altered expression have been identified. Differential expression of a
selection of these genes has also been confirmed on northern blots.
The analysis of function and mycorrhizal specificity of selected genes
has been initiated.
Key words: Glomus versiforme , Medicago truncatula, cDNA arrays, gene profiling, mycorrhizal