A response to Gupta et al. 2018 regarding the MoT3 assay

Authors: YASUHARA-BELL, JARRED - Kansas State University; Pieck, Michael; Wright, Amy; FARMAN, MARK - University Of Kentucky; Peterson, Gary; STACK, JAMES - Kansas State University; VALENT, BARBARA - Kansas State University; Pedley, Kerry

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/13/2018
Publication Date: 3/11/2019
Citation: Yasuhara-Bell, J., Pieck, M.L., Ruck, A.L., Farman, M.L., Peterson, G.L., Stack, J.P., Valent, B., Pedley, K.F. 2019. A response to Gupta et al. 2018 regarding the MoT3 assay. Phytopathology. 109:509-511. https://doi.org/10.1094/PHYTO-10-18-0397-LE.
DOI: https://doi.org/10.1094/PHYTO-10-18-0397-LE

Interpretive Summary:

Technical Abstract: Our goal in developing the MoT3 diagnostic assay was to differentiate the aggressive Triticum isolates, currently restricted to South America and Bangladesh, from all other Magnaporthe oryzae isolates, not just from rice pathogens. The challenge was to find sequences that differentiate Triticum pathogens from extremely closely-related isolates from Lolium species. This distinction gained practical importance when a native U.S. Lolium isolate (WBKY11-15) was recovered from a blasted wheat head in Kentucky in 2011. Isolation of this native Lolium strain from wheat alerted us to the ability of some Lolium isolates to infect wheat in the field, although Lolium strains are much less aggressive pathogens on wheat than Triticum strains. The MoT3 primers amplify a sequence, WB12, which was perfectly correlated with 113 Triticum lineage strains and a total of 285 total M. oryzae strains from 11 host-preference groups. What appeared to be exceptions were not; for example, 2 out of 115 isolates tested from wheat in the field, are members of the Lolium lineage according to phylogenetic analyses. Further testing utilizing isolates of M. oryzae obtained from infected rice and wheat in Bangladesh further validate the accuracy of the assay.