Understanding Northern corn leaf blight (NCLB) disease resistance in maize: Past developments and future directions

Maize (Zea mays L.) is an essential food crop grown all over the world, extensively used as animal feed, human food, and to produce biofuel. Northern corn leaf blight (NCLB) is one of the most destructive foliar diseases that affect maize crop, causing significant yield losses globally. The most efficient method for controlling NCLB is thought to be a combination of quantitative regulation by several genes and varietal resistance based on Ht genes. Despite decades of developing varietal resistance and identifying hundreds of QTLs, the control of NCLB remains a major challenge for maize yield production. Modern genomics tools integration into molecular plant breeding is essential to identify significant loci for NCLB resistance. Genomics-assisted breeding (GAB), followed by precision phenotyping, is a prerequisite to understand the genetic makeup and molecular mechanisms of disease resistance. Genome-editing technique (CRISPR-Cas) has emerged as an effective tool to accelerate crop breeding programs for the disease resistance. This review attempts to convey an overview of the NCLB disease pathosystem, its global distribution, and breeding strategies utilized for NCLB resistance in maize. We propose that GAB and genome editing tools hold great potential for developing NCLB-resistant maize varieties.