Submitted to: Extension Magazine
Publication Type: Other
Publication Acceptance Date: March 15, 2009
Publication Date: April 15, 2009
Citation: Tremblay, A., Matthews, B.F. 2009. Laser capture microdissection, a new technique to collect specific cells. Extension Magazine. 4:4
Soybean is one of the top five agricultural products in the U.S. Protection of soybean from present and new exotic pathogens is very important for soybean production. Soybean rust is caused by the obligate fungus Phakopsora pachyrhizi Sydow, an exotic pathogen. This pathogen causes yield losses due to premature defoliation, fewer seeds per pod and decreased number of filled pods per plant. From this perspective we identified genes from P. pachyrhizi that might be involved in the infection process specifically during the uredinium formation. Thus, we constructed and analyzed cDNA library to identify candidate genes. The library was constructed from RNA isolated from uredinium formed by P. pachyrhizi on the under side of leaves. Uredinia were isolated by laser capture microdissection. A portion of the library was sequenced, contigs were formed, and blast searches were conducted to determine the identity of the genes. We found 41 expressed sequence tags (EST) with significant similarities to (Evalue< 10-5) to sequences deposited in the NCBI non-redundant protein database. Of those ESTs, 61% was similar to fungal sequences. Even if 59% of those significant ESTs shown identities with hypothetical proteins or proteins with unknown function, some shown identities with proteins involved in energy production, cellular communication/signal transduction, and transcription. RT-PCR was used to confirm expression of six rust genes. In the future, target pathogen genes will be studied to determine if they can be used to control ASR in soybean.