Cochliobolus heterostrophus strain HAW225 is a MAT1-1, Tox1+, field isolate, collected in Hawaii around the time of the Southern Corn Leaf Blight (SCLB) epidemic. Like the reference strain C4, it is a race T, T-toxin producing strain. As described for strain C4, in 1970 race T of C. heterostrophus caused the worst epidemic in US agricultural history, destroying more than 15% of the maize crop. Subsequent research demonstrated that the epidemic was triggered by the unfortunate confluence of complex DNA recombination events in both the fungal pathogen and the plant host. Before 1970, C. heterostrophus was known as an endemic pathogen of minor economic importance, first described in 1925 by Drechsler; after the appearance of race T, this race was named “race O”. Note both fungal races are pathogenic to corn, but race T is highly and specifically virulent on Texas male sterile cytoplasm (Tcms) corn.
References:
- Drechsler, C. 1925. Leaf spot of maize caused by Ophiobolus heterostrophus, the ascigerous stage of a Helminthosporium exhibiting bipolar germination. J. Agric. Res. 31: 701-726.
Genome Reference(s)
Haridas Sajeet, González Jennifer B., Riley Robert, Koriabine Maxim, Yan Mi, Ng Vivian, Rightmyer Adriana, Grigoriev Igor V., Baker Scott E., Turgeon B. Gillian
T-Toxin Virulence Genes: Unconnected Dots in a Sea of Repeats
mBio. 2023;: doi: 10.1128/mbio.00261-23