Description
Curvularia leaf spot (CLS) in maize is caused by the fungus Curvularia lunata (Cluna). Its introduction into the United States was first reported in Louisiana in 2017 and has since been observed in multiple states (Crop Protection Network, 2020). This fungus can overwinter in corn residue, infect new plants via splash- or wind-dispersion, and infect all developmental stages of corn. The impact of this disease on yield loss is yet to be determined in the US, however, in China it is one of the top three leaf diseases causing economic losses (Garcia-Aroca et al., 2018; Wang et al., 2022). Detection and identification of Cluna is labor intensive, time-consuming, and imprecise, relying on visual examination of lesions, isolation and creation of pure cultures, and morphological characterization of conidia (Hou et al., 2013).
3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON) are derivatives of the B-trichothecene metabolite, deoxynivalenol (DON). These toxins are primarily produced by Fusarium pathogens, primarily Fusarium graminearum. Disease causing pathogens not only cause significant yield loss, but the mycotoxin contamination can pose health hazards to humans and livestock (Puri and Zhong, 2010; Nielsen et al., 2012). Approximately half of the genes needed for biosynthesis of trichothecenes are in the trichothecene biosynthetic gene (TRI) cluster. This assay determines whether Fusarium spp. have the ability to produce 3- and 15-ADON target genes within this cluster (Kulik, 2011; Goswami and Kistler, 2004).
This project was funded by the National Predictive Modeling Tool Initiative.
References
(2020) Curvularia Leaf Spot of Corn, Crop Protection Network.
Garcia-Aroca, T., Doyle, V., Singh, R., Price, T., and Collins, K. (2018) First Report of Curvularia Leaf Spot of Corn, Caused by Curvularia lunata, in the United States, Plant Health Progress 19, 140-142.
Wang, S., Lu, Z., Lang, B., Wang, X., Li, Y., and Chen, J. (2022) Curvularia lunata and Curvularia Leaf Spot of Maize in China, ACS Omega 7, 47462-47470.
Hou, J. M., Ma, B. C., Zuo, Y. H., Guo, L. L., Gao, S. G., Wang, Y. Y., and Liu, T. (2013) Rapid and sensitive detection of Curvularia lunata associated with maize leaf spot based on its Clg2p gene using semi-nested PCR, Letters in applied microbiology 56, 245-250.
Puri, K. D., and Zhong, S. (2010) The 3ADON population of Fusarium graminearum found in North Dakota is more aggressive and produces a higher level of DON than the prevalent 15ADON population in spring wheat, Phytopathology 100, 1007-1014.
Nielsen, L. K., Jensen, J. D., Rodríguez, A., Jørgensen, L. N., and Justesen, A. F. (2012) TRI12 based quantitative real-time PCR assays reveal the distribution of trichothecene genotypes of F. graminearum and F. culmorum isolates in Danish small grain cereals, International journal of food microbiology 157, 384-392.
Kulik, T. (2011) Development of TaqMan Assays for 3ADON, 15ADON and NIV Fusarium Genotypes Based on Tri12 Gene, Cereal Research Communications 39, 200-214.
Goswami, R., and Kistler, H. (2004) Goswami, R. S. & Kistler, H. C. Heading for disaster: Fusarium graminearum on cereal crops. Mol. Plant Pathol. 5, 515-525, Molecular plant pathology 5, 515-525.