MPK3-mediated phosphorylation inactivates MYB4 to promote FIT-dependent iron acquisition.
Iron (Fe) is an essential micronutrient for plant growth, and its homeostasis is critically regulated by the transcription factor FIT in response to deficiency. Here, we identify the R2R3-MYB transcription factor MYB4 as a previously unknown negative regulator of Fe acquisition. MYB4 directly interacts with FIT, compet...