Poster: Genomic & proteomic resources

Abs # 879: A Proteomic Study of Methyl Jasomonate Elicited Medicago truncatula Cell Cultures

Presenter:	Elmer, Aaron M., amelmer@noble.org
Authors	Elmer, Aaron M. (A)   Lei, Zhentian  (A)   Sumner, Lloyd W. (A)
Affiliations:	(A): The Samuel Roberts Noble Foundtion

The proteome of Medicago truncatula suspension cells was profiled using two-dimensional electrophoresis (2-DE) to yield a comprehensive protein reference map. Coomassie Brilliant Blue R-250 was used to visualize more than 1600 protein spots with molecular weights ranging from 114,630 to 13,489 Da. Protein spots were excised, subjected to in-gel trypsin digestion and analyzed using nano-scale high performance liquid chromatography (HPLC) coupled with a tandem quadrupole-time of flight (Q-TOF) mass spectrometer (QSTAR Pulsar i). The resulting spectral data were queried against a custom legume protein database using the MASCOT search engine. This approach yielded confident protein identifications for 83% of the protein spots. Although a total of 2570 proteins were identified in the 1377 protein spots, only 901 independent accession numbers were represented. The identified proteins were classified according to their putative functions. A survey of the glycolytic and TCA cycle enzymes showed that only hexose kinase was not identified. Although not as complete, the enzymes involved in lignin and flavanoid biosynthesis were well represented in the M. truncatula suspension cell proteome. In addition to metabolic pathways, there was a significant portion of the ubiquitin protein degradation pathway identified. This work was the foundation for additional proteomic analyses of methyl jasmonate elicited suspension cell cultures. A 48 hour time course was used to study the relative changes in protein expression following treatment with 500 μM methyl jasmonate.