|VAN DE MORTEL, J|
|Samac, Deborah - Debby|
Submitted to: Molecular Plant Microbe International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 7/11/2001
Publication Date: N/A
Technical Abstract: Due to the ability of forming both symbiotic and pathogenic associations, a self-pollinated diploid legume Medicago truncatula has been selected as a model plant species to study the functional genomics of plant-microbe interactions. 5'-EST sequencing from 12 M. truncatula cDNA libraries has resulted in more than 33,000 entries. To initiate high-throughput expression profiling of these ESTs, pilot sets of clones were spotted onto nylon membranes (macroarrays) or glass slides (microarrays), and analyzed by hybridization with various cDNA probes. These assays have focused on two aspects of plant-microbe interactions: symbiotic relations with N2-fixing bacterium Sinorhizobium meliloti, and plant interactions with pathogenic fungi Phytophthora medicaginis and Colletotrichum trifolii. Macroarray hybridization revealed dozens of plant genes with altered expression levels as a result of plant-microbe interaction. A pilot Kiloclone Microarray containing 1,000 clones was tested with several cDNA probes to optimize microarray hybridization procedure and to characterize microbe-elicited tissues. Project sequences, along with other publically available data, have been used to construct a Gene Index (www.tigr.org) that represents a minimally redundant set of M. truncatula sequences. Analysis of EST frequencies in the different libraries reveals numerous examples of a tissue-specific pattern of gene expression. The Gene Index will become a platform for selecting and microarray-based expression profiling of an entire non-redundant set of M. truncatula ESTs -- a Unigene Set. The research was supported by NSF grant # DBI 9872664.