Abstract
Stem lodging poses a major challenge to modern maize production by significantly reducing yield, impairing grain quality, and complicating mechanical harvest. Our previous work identified ZmmiR528 as a key post-transcriptional regulator of lignin biosynthesis and lodging resistance, highlighting its potential as a breeding target. However, strategies to leverage this gene in breeding programs have remained unexplored. In this study, we characterized stem lodging resistance in a diverse panel of 263 maize accessions under field conditions and performed sequencing of the ZmMIR528a and ZmMIR528b loci. An association analysis identified a single-nucleotide polymorphism (SNP) in the ZmMIR528b promoter that was significantly correlated with the stem lodging resistance index. Accessions carrying the Pro-C allele at this locus demonstrated a significantly higher stem lodging resistance index and greater stem lignin content than those with the Pro-T allele. Luciferase assays indicated that the Pro-C haplotype conferred lower transcriptional activity than the Pro-T haplotype. Consistent with this, stem-loop RT-qPCR revealed that mature ZmmiR528 abundance was significantly lower in accessions harboring the Pro-C allele. We subsequently developed a cleaved amplified polymorphic sequence (CAPS) marker based on this SNP and validated its efficacy in a panel of ten diverse inbred lines. Collectively, our findings identify a novel functional promoter allele that enhances lodging resistance by repressing ZmmiR528 expression, thereby providing a validated molecular tool for breeding lodging-resistant maize. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11032-026-01658-5.