The maize mitogen-activated protein kinase kinase kinase gene ZmMAPKKK45 is associated with multiple disease resistance

Authors: ZHONG, TAO - North Carolina State University; OLUKOLU, BODE - University Of Tennessee; BIAN, YANG - North Carolina State University; XUE, SHANG - North Carolina State University; WISSER, RANDALL - University Of Montpellier; OJIAMBO, PETER - North Carolina State University; Holland, James; YANG, QIN - North Carolina State University; Balint Kurti, Peter

Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2025
Publication Date: 12/18/2025
Citation: Zhong, T., Olukolu, B., Bian, Y., Xue, S., Wisser, R., Ojiambo, P., Holland, J.B., Yang, Q., Balint Kurti, P.J. 2025. The maize mitogen-activated protein kinase kinase kinase gene ZmMAPKKK45 is associated with multiple disease resistance. New Phytologist. 249 (6); 3003-3020. https://doi.org/10.1111/nph.70828.
DOI: https://doi.org/10.1111/nph.70828

Interpretive Summary: Using mapping, transgenic and mutational approaches, a gene called ZmMAPKKK45 was shown to impart significant levels of resistance against multiple fungal leaf diseases in maize, including southern leaf blight, northern leaf blight and gray leaf spot. ZmMAPKKK45 also enhances the production of reactive oxygen species during the defense response, which is likely connected to its effect on disease resistance.

Technical Abstract: Southern leaf blight (SLB), caused by the necrotrophic fungal pathogen Cochliobolus heterostrophus, is a major foliar disease of maize worldwide. Association mapping using a panel of 270 diverse inbred lines identified fourteen single nucleotide polymorphism (SNP) variants significantly associated with SLB resistance corresponding to ten candidate genes. Using a combination of mutant and transgenic analysis we demonstrated that one of the candidate genes, ZmMAPKKK45, encoding a mitogen-activated protein kinase kinase kinase (MAPKKK), was the causal gene conferring SLB resistance at a locus defined by two associated SNPs on chromosome 3. We demonstrated that ZmMAPKKK45 conferred resistance to two other foliar diseases of maize, northern leaf blight (NLB) and gray leaf spot (GLS), and enhanced production of reactive oxygen species (ROS) during the defense response. Furthermore, we found ZmMAPKKK45 enhances ROS production, probably by increasing the expression of maize respiratory burst oxidase homolog genes (ZmRBOHs) and we suggest that this is associated with its effect on multiple disease resistance.