Itaconate identified as growth regulator in corn

Scientists have discovered that itaconate also acts on plants. The compound, derived from the Krebs cycle, acts as a regulator of gene expression and protein modifications in plant species. Its endogenous presence has been confirmed in corn e Arabidopsis. The discovery expands horizons on plant metabolism.

The external application of itaconate produced divergent effects. In corn, it stimulated the growth of the aerial part. In Arabidopsis, inhibited cell formation and division in the roots.

The responses were dose-dependent. High concentrations suppressed cell divisions and root elongation. When using a cell cycle marker line, a decrease in the number of actively dividing cells was evident after treatment with the compound.

Itaconate also altered ATP levels, chlorophyll and response to abiotic stresses. In Arabidopsis, reduced chlorophyll and hydrogen peroxide levels. The compound inhibited cytokinin hormonal pathways and altered abscisic acid signaling. In interaction with salt and mannitol stresses, there was no additional effect, indicating overlapping mechanisms.

The study used several molecular techniques. Transcriptomic analyses revealed hundreds of altered genes. Photosynthesis and oxidative response pathways emerged as affected. Crucial proteins such as SDH1-1 and ABA1 showed affinity for itaconate.

The chemoproteomic approach detected modifications in cysteines of carbon cycle and glycolysis enzymes. Some of these proteins also undergo modification in human macrophages.

XAL2, a key transcription factor in root development, was downregulated. Mutants for this gene showed resistance to itaconate. Overexpressing lines showed the opposite response: root growth increased under itaconate.

To test its endogenous production, scientists introduced the IRG1 gene into Arabidopsis. The resulting plants exhibited taller stems and higher itaconate concentrations. Interestingly, these lines showed favored, not suppressed, growth, suggesting that the origin and context of production influence the effects of the compound.

The study points to itaconate as a link between metabolism, stress and hormonal regulation. Its action on central pathways could pave the way for agricultural applications. However, there is still a lack of clues about the gene that synthesizes it in plants.

More information at doi.org/10.1126/sciadv.adt7463