Submitted to: Biomed Central (BMC) Plant Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/27/2009
Publication Date: 4/27/2009
Citation: Thibivilliers, S., Joshi, T., Campbell, K., Scheffler, B., Borerma, R., Xu, D., Cooper, B., Nguyen, H.T., Stacey, G. 2009. Generation of Phaseolus vulgaris ESTs and investigation of the regulation upon Uromyces appendiculatus infection. Biomed Central (BMC) Plant Biology. 9:46. Interpretive Summary: Soybeans are very susceptible to the soybean rust fungus, which can cause considerable crop loss. By contrast, the common bean plant has resistance to its own common bean rust and soybean rust. Here, 90 different disease response genes from common bean were found to be expressed during resistance reactions to common bean rust infection. Then, similar genes were found in soybean and shown to also be differentially regulated during soybean rust infection. These studies reveal that soybean rust is effective in altering the expression of disease resistance genes in soybean whose homologues give protection in common beans. These data are most likely to be useful to scientists at universities, government agencies and companies who are interested in understanding why soybean plants are susceptible to soybean rust or who are interested in a new source disease resistance genes that could protect the soybean crop.
Technical Abstract: : No soybean (Glycine max) cultivars are available that show field resistance to Asian soybean rust (ASR) caused by the biotrophic fungus Phakopsora pachyrhizi. However, in a closely related crop, Phaseolus vulgaris (common bean) several resistant genes were identified that confer resistance to examined Uromyces appendiculatus (bean rust) infection. The work described whether the common bean-rust phatoystem could be used as a surrogate to better understand the soybean-rust phatosystem. A bean cDNA library composed of 10,581 unisequences was constructed and enriched in sequences regulated by either bean rust race 41, a virulent strain, or race 49, an avirulent strain on cultivar Early gallatin carrying the resistance gene Ur-4. The construction of this library allowed the identification of 6,202 new bean ESTs, significantly adding to the available sequences in the public. Regulation of selected bean genes in response to bean rust infection was confirmed by qRT-PCR. Gene expression was similar for both race 41 and 49 during the first 48 hours of the infection process but varied significantly at the later time points (72-96 hours). Likely soybean orthologues of 26 bean genes were identified and their regulation during ASR infection was analyzed. The results showed that 75% of these soybean genes were differentially regulated by ASR infection.