ZmGLN5 validated as candidate gene for maize ear rot resistance

A multi-method genetic study has identified ZmGLN5, which encodes glutamine synthetase 5, as a key candidate gene underlying resistance to Gibberella ear rot in maize. The research combined comparative transcriptomics, weighted gene co-expression network analysis, meta-quantitative trait locus analysis, gene-based association testing and mutagenesis experiments. Gibberella ear rot is caused by the fungal pathogen Fusarium graminearum and can severely affect maize yield and grain quality worldwide.

Although numerous genetic loci associated with resistance have been reported, the functional genes underlying resistance remain largely uncharacterized. To investigate this genetic basis, the researchers compared gene expression in two maize lines with contrasting resistance to the disease. Their comparative transcriptome analysis found that differently expressed genes were associated mainly with defense-related pathways, including phenylpropanoid biosynthesis, glutathione metabolism, flavonoid biosynthesis and MAPK signaling.

The researchers integrated the transcriptomic results with weighted gene co-expression network analysis and meta-quantitative trait locus results, narrowing the search to nine candidate genes associated with maize resistance to Gibberella ear rot. ZmGLN5 was then selected for further validation through gene-based association analysis and mutagenesis experiments. Together, these analyses characterized ZmGLN5 as a key candidate underlying the resistance trait rather than merely identifying it as a differentially expressed gene.

Natural variation in the first intron of ZmGLN5 was used to develop an insertion/deletion marker. Its genetic effect was subsequently validated in a panel of 150 maize inbred lines, providing an additional test of the gene’s association with resistance. The study also found evidence suggesting that ZmGLN5 may have a regulatory role in kernel number per row and ear length.

The supplied findings do not establish the molecular mechanism connecting ZmGLN5 to these two agronomic traits, nor do they demonstrate that a particular allele confers resistance across genetic backgrounds or environments. Overall, the study provides a genetically validated candidate and a corresponding DNA marker for maize researchers working on Gibberella ear rot. Its results also identify several defense-related pathways that were associated with the resistant and susceptible transcriptomes.

The scope of the evidence comprises two contrasting maize lines, a comparative transcriptome analysis, an integrated co-expression and quantitative trait locus screen, targeted gene validation, and association testing in 150 inbred lines.

Subject of Research: Genetic identification of a maize candidate gene for resistance to Gibberella ear rot

Article Title: Identification of ZmGLN5, a candidate gene for resistance to Gibberella ear rot in maize

Article References: Ma, L., Ma, L., Zhang, S., Zhang, H., Song, X., Zhang, Z., Mao, Y., Lu, H., Chen, G., Hao, D., & Zhou, G. (2026). Identification of ZmGLN5, a candidate gene for resistance to Gibberella ear rot in maize. Molecular Biology Reports, 53(1), Article 1499. https://doi.org/10.1007/s11033-026-12611-2

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12611-2

Keywords: ZmGLN5, maize, Gibberella ear rot, Fusarium graminearum, disease resistance, quantitative trait loci, comparative transcriptomics, gene-based association, glutamine synthetase, insertion/deletion marker, Identification, candidate