CRISPR Boosts Maize Resistance to Southern Corn Rust

Researchers from Jilin Academy of Agricultural Sciences and partners have investigated the role of ZmJAZ12 in maize resistance to southern corn rust (SCR). Caused by the fungus Puccinia polysora, SCR is a major disease that can reduce maize yields worldwide. The study reveals significant insights into how ZmJAZ12 influences the plant's defense responses and its potential for use in maize breeding.

The researchers developed maize plants that either overexpressed or lacked the gene using CRISPR-Cas9 gene editing. The study found that maize plants overexpressing the gene showed increased disease susceptibility, while plants in which ZmJAZ12 was knocked out were more resistant. Further analysis showed that ZmJAZ12 interacts with ZmMYC5, a transcription factor involved in jasmonic acid (JA) signaling.

The findings showed that ZmJAZ12 suppresses defense responses by affecting both JA and salicylic acid (SA) signaling pathways. Resistant maize varieties had lower ZmJAZ12 activity, suggesting that the gene functions as a susceptibility factor. The researchers said ZmJAZ12 could serve as a potential target for breeding maize with improved resistance to southern corn rust.

For more information, read the study from Molecular Plant Pathology.