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ARS Home » Midwest Area » Wooster, Ohio » Corn, Soybean and Wheat Quality Research » Research » Publications at this Location » Publication #422331
Research Project: Detection and Characterization of Genetic Resistance to Corn and Soybean Viruses

Location: Corn, Soybean and Wheat Quality Research

Title: Targeted knockout of a host peroxisomal peptidase confers field resistance to maize lethal necrosis

Author
item JUNG, MARK - Corteva Agriscience
item WEN, ZHENGYU - International Maize & Wheat Improvement Center (CIMMYT)
item HUMBERT, SABRINA - Corteva Agriscience
item LU, FENGZHONG - International Maize & Wheat Improvement Center (CIMMYT)
item DELEON, ALYSSA - Corteva Agriscience
item MARSHALL, LISA - Corteva Agriscience
item HASTINGS, CRAIG - Corteva Agriscience
item CARTWRIGHT, HEATHER - Corteva Agriscience
item THILGES, KATHERINE - Corteva Agriscience
item WANG, NING - Corteva Agriscience
item BRECKENRIDGE, KASSANDRA - Corteva Agriscience
item WU, EMILY - Corteva Agriscience
item RYAN, LARISA - Corteva Agriscience
item FENGLER, KEVIN - Corteva Agriscience
item SIMCOX, KEVIN - Corteva Agriscience
item THATCHER, SHAWN - Corteva Agriscience
item LLACA, VICTOR - Corteva Agriscience
item WOOLLUMS, GRACE - Corteva Agriscience
item SANDER, JEFFRY - Corteva Agriscience
item XU, DEPING - Corteva Agriscience
item BEATTY, MARY - Corteva Agriscience
item BRINK, KENT - Corteva Agriscience
item FEDOROVA, MARIA - Corteva Agriscience
item JONES, MARK - Retired ARS Employee
item Ohlson, Erik
item SURESH, L - International Maize & Wheat Improvement Center (CIMMYT)
item BEYENE, YOSEPH - International Maize & Wheat Improvement Center (CIMMYT)
item OLSEN, MIKE - International Maize & Wheat Improvement Center (CIMMYT)
item OGUGO, VERONICA - International Maize & Wheat Improvement Center (CIMMYT)
item ALAKONYA, AMOS - International Maize & Wheat Improvement Center (CIMMYT)
item MURITHI, ANN - International Maize & Wheat Improvement Center (CIMMYT)
item MUGO, STEPHEN - International Maize & Wheat Improvement Center (CIMMYT)
item KARANJA, JAMES - Kenya Agricultural And Livestock Research Organization
item BUDDUPALLI, PRASANNA - International Maize & Wheat Improvement Center (CIMMYT)
item PIXLEY, KEVIN - International Maize & Wheat Improvement Center (CIMMYT)
item ALBERTSEN, MARC - Kenya Agricultural And Livestock Research Organization
item JONES, TODD - Corteva Agriscience
item MEELEY, ROBERT - Corteva Agriscience
item GUTTERSON, NEAL - Corteva Agriscience
item MAZUR, BARBARA - Corteva Agriscience
item DHUGGA, KANWARPALA - International Maize & Wheat Improvement Center (CIMMYT)

Submitted to: Proceedings of the National Academy of Sciences (PNAS)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2026
Publication Date: 4/30/2026
Citation: Jung, M., Wen, Z., Humbert, S., Lu, F., Deleon, A., Marshall, L., Hastings, C., Cartwright, H., Thilges, K., Wang, N., Breckenridge, K., Wu, E., Ryan, L., Fengler, K., Simcox, K., Thatcher, S., Llaca, V., Woollums, G., Sander, J., Xu, D., Beatty, M., Brink, K., Fedorova, M., Jones, M., Ohlson, E.W., Suresh, L.M., Beyene, Y., Olsen, M., Ogugo, V., Alakonya, A., Murithi, A., Mugo, S., Karanja, J., Buddupalli, P., Pixley, K., Albertsen, M., Jones, T., Meeley, R., Gutterson, N., Mazur, B., Dhugga, K.S. 2026. Targeted knockout of a host peroxisomal peptidase confers field resistance to maize lethal necrosis . Proceedings of the National Academy of Sciences (PNAS). 123(18) Article e2535202123. https://doi.org/10.1073/pnas.2535202123.
DOI: https://doi.org/10.1073/pnas.2535202123

Interpretive Summary: Maize lethal necrosis (MLN), caused by coinfection by maize chlorotic mottle virus (MCMV) and a potyvirus, is one of the most important virus diseases of corn. The disease typically causes approximately 25% yield losses and up to 100% under severe conditions. Until now, no MCMV resistance genes had been identified. In this study, an MCMV resistance gene was identified on chromosome 6 in the corn inbred line KS23-6. Most corn lines have a susceptibility factor conferred by a peroxisomal peptidase gene required for MCMV replication in the host. However, KS23-6 has an alternate version of this gene that prevents efficient virus replication. Gene editing was performed on an elite, MLN susceptible corn line to knockout the function of this peptidase gene. By knocking out this gene, similar MLN resistance was discovered in the edited line as in KS23-6. These findings will allow for the rapid development and release of elite, MLN resistant maize varieties by seed companies. These resistant varieties will immediately benefit growers where MLN is endemic and they provide a safeguard for growers in the US should MLN re-emerge.

Technical Abstract: Two viruses collectively cause maize lethal necrosis (MLN), a disease that threatens food security for smallholder farmers in sub-Saharan Africa. A single recessive QTL on chromosome 6, identified in a line, KS23-6, from Thailand, conferred strong resistance. Fine genetic mapping elucidated a single amino acid alteration in a unique peroxisomal peptidase as the causal factor for resistance. An elite, susceptible maize line with a knocked-out peptidase demonstrated resistance to MLN comparable to KS23-6 and performed as effectively as the parental line in the absence of disease pressure in the field in Kenya. Knocking out the peptidase eliminated one of the two MLN viruses from the plant. We can now rapidly reintroduce MLN-resistant versions of susceptible lines to help safeguard the livelihoods of smallholders in Africa.