Submitted to: International Conference on Legume Genomics and Genetics
Publication Type: Abstract Only
Publication Acceptance Date: April 9, 2006
Publication Date: April 9, 2006
Citation: Tesfaye, M., Bucciarelli, B., Samac, D.A., Vance, C.P. 2006. Transcript analysis of Medicago spp. Third International Conference on Legume Genomics and Genetics, April 9-13, 2006, Brisbane, Australia. p. 79. Technical Abstract: Medicago truncatula, the model plant for legume biology, has been the subject of extensive structural and functional genomics study. The M. truncatula gene index at the institute for genomic research contains expressed sequence tags (EST) that are publicly available (www.tigr.org). In addition, the international effort to sequence the genespace of the M. truncatula genome is also making BAC sequences publicly available via several informatic resources (www.medicago.org, among others). Taking advantage of the publicly available ESTs as well as Medicago genome sequences, we took a bioinformatics and a functional genomics approach to identify and evaluate putatively Sinorhizobum-inoculated tissue specific genes in M. truncatula. One group of in silico identified transcripts encodes eight TCs with protein sequences similar to plant disease resistance (R) genes of the nucleotide binding site-leucine rich repeat type. Expression of selected R genes was enhanced in effective nodules, and transcripts were also detected in bacterial-conditioned ineffective nodules. Homologous R gene sequences have also been identified in the Medicago genome. However, their functional importance in nodules remains to be established. Other results from the cDNA array analysis of M. truncatula nodules showed remarkable agreements with L. japonicus for expression of most nodule-enhanced genes. Because of the close relationship of M. truncatula with the cultivated tetraploid alfalfa (M. sativa), work is also in progress to utilize the GeneChip® Medicago Genome Array from Affymetrix to compare transcript profiling in M. truncatula and M. sativa. Detailed results will be presented.