GOLVEN peptide signaling through RGI receptors and MPK6 restricts asymmetric cell division during root initiation (Nature Plants)

Lateral root starts development starts with an asymmetric cell division in the founder cell. In this study, Fernandez et al. explored the role of peptide signaling this process. The authors started with the previous finding that GOLVEN peptides are involved in lateral root initiation, as overexpression of GLV6 causes a strong reduction in number of emerged lateral roots as a consequence of excess asymmetric cell divisions interfering with lateral root development. The authors used this overexpression line for a suppressor screen to find downstream signaling components, and identified mutations in MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6). The authors demonstrated that GLV6 peptide treatment rapidly phosphorylates MPK6. Additionally, they identified three RGI receptors that act as GLV receptors. Overall, the work suggests a lateral root development model in which an activator induces production of GLV peptides which are perceived by RGIs and inhibit further asymmetric cell divisions through downstream MPK6 signaling. (Summary by Arif Ashraf @aribidopsis) Nature Plants 10.1038/s41477-020-0645-z