Targeted knockout of a host peroxisomal peptidase confers field resistance to maize lethal necrosis
Abstract
Maize lethal necrosis (MLN) is a severe disease caused by the combined infection of maize chlorotic mottle virus (MCMV) and a potyvirus, most often sugarcane mosaic virus (SCMV). This disease seriously threatens food security across sub-Saharan Africa (SSA). We investigated a major-effect quantitative trait locus for resistance on chromosome 6, named the maize lethal necrosis susceptibility locus 1 ( qMLNS1 ), derived from the Thai line KS23-6. Fine mapping and CRISPR-Cas9 editing of the candidate genes within the narrowed 105 kb interval revealed a peroxisomal peptidase as the underlying cause of susceptibility. Confocal microscopy confirmed the localization of the MLNS1 protein within peroxisomes. Targeted knockout of the Mlns1 gene in the susceptible elite line CML536 from SSA conferred resistance comparable to KS23-6 in field trials conducted in Naivasha, Kenya. This knockout specifically blocked MCMV accumulation without affecting SCMV. The edited lines showed no yield penalty or agronomic defects under disease-free conditions. Our findings uncover a mechanistic link between a peroxisomal enzyme and viral susceptibility. They also establish a rapid, scalable gene editing strategy for incorporating MLN resistance into elite germplasm, offering a model for combating similar viral diseases in staple crops globally.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (41)
Mark Jung
Corteva Agriscience
Zhengyu Wen
International Center for Maize and Wheat Improvement
Sabrina Humbert
Corteva Agriscience
Fengzhong Lu
International Center for Maize and Wheat Improvement
Alyssa DeLeon
Corteva Agriscience
Lisa Marshall
Corteva Agriscience
Craig Hastings
Corteva Agriscience
Heather Cartwright
Corteva Agriscience
Katherine Thilges
Corteva Agriscience
Ning Wang
Kassandra Breckenridge
Corteva Agriscience
Emily Wu
Larisa Ryan
Corteva Agriscience
Kevin Fengler
Corteva Agriscience
Kevin Simcox
Corteva Agriscience
Shawn Thatcher
Corteva Agriscience
Victor Llaca
Corteva Agriscience
Grace Woollums
Corteva Agriscience
Jeffry Sander
Corteva Agriscience
Deping Xu
Corteva Agriscience
Mary Beatty
Corteva Agriscience
Kent Brink
Corteva Agriscience
Maria Fedorova
Mark Jones
Corn, Soybean, and Wheat Quality Research Unit, United States Department of Agriculture-Agricultural Research Service
Erik Ohlson
Corn, Soybean, and Wheat Quality Research Unit, United States Department of Agriculture-Agricultural Research Service
L. M. Suresh
International Center for Maize and Wheat Improvement
Yoseph Beyene
International Center for Maize and Wheat Improvement
Michael Olsen
International Center for Maize and Wheat Improvement
Veronica Ogugo
International Center for Maize and Wheat Improvement
Amos Alakonya
International Center for Maize and Wheat Improvement
Ann Murithi
International Center for Maize and Wheat Improvement
Stephen Mugo
International Center for Maize and Wheat Improvement
James Karanja
Kenyan Agricultural and Livestock Research Organization
Prasanna Boddupalli
International Center for Maize and Wheat Improvement
Kevin Pixley
International Center for Maize and Wheat Improvement
Marc Albertsen
Corteva Agriscience
Todd Jones
Corteva Agriscience
Robert Meeley
Corteva Agriscience
Neal Gutterson
Corteva Agriscience
Barbara Mazur
Corteva Agriscience
Kanwarpal S. Dhugga
International Center for Maize and Wheat Improvement