A working model for the <i>ZmERF2</i>-<i>ZmARF1</i>-<i>ZmLBD1</i> signaling module in response to low-Pi stress.

The graph on left shows that maize has less lateral root growth under high phosphorus conditions. ZmARF1 is inhibited from regulating ZmLBD1 and lateral root development by ZmERF2 by ubiquitination and degradation. On the contrary, the graph on the right shows the promotion of lateral root development in maize under low-phosphorus conditions. Transcriptional repression of ZmARF1 by ZmERF2 is limited under low Pi, abundance of ZmARF1 results in an increased ZmLBD1 transcription and consequently lateral root development.