Transcriptome profiling of eight Zea mays lines identifies genes responsible for the resistance to Fusarium verticillioides.

BACKGROUND

The cultivation of maize (Zea mays L.), one of the most important crops worldwide for food, feed, biofuels, and industrial applications, faces significant constraints due to Fusarium verticillioides, a fungus responsible for severe diseases including seedling blights, stalk rot, and ear rot. Its impact is worsened by the fact that chemical and agronomic measures used to control the infection are often inefficient. Hence, genetic resistance is considered the most reliable resource to reduce the damage. This study aims to elucidate the genetic basis of F. verticillioides resistance in maize.

RESULTS

Young seedlings of eight divergent maize lines, founders of the MAGIC population, were artificially inoculated with a F. verticillioides strain. Phenotypic analysis and transcriptome sequencing of both control and treated samples identified several hundred differentially expressed genes enriched in metabolic processes associated with terpene synthesis. A WGCNA further refined the pool of genes with potential implications in disease response and found a limited set of hub genes, encoding bZIP and MYB transcription factors, or involved in carbohydrate metabolism, solute transport processes, calcium signaling, and lipid pathways. Finally, additional gene resources were provided by combining transcriptomic data with previous QTL mapping, thereby shedding light on the molecular mechanisms in the maize-F. verticillioides interaction.

CONCLUSIONS

The transcriptome profiling of eight divergent MAGIC maize founder lines with contrasting levels of Fusarium verticillioides resistance combined with phenotypic analysis, clarifies the molecular mechanisms underlying the maize-F. verticillioides interaction.