ZmARF1 positively regulates low phosphorus stress tolerance via modulating lateral root development in maize

Area of Science:

• Plant Biology
• Molecular Genetics
• Agricultural Science

Background:

• Phosphorus (P) deficiency severely limits plant growth and productivity.
• Auxin response factors (ARFs) are key regulators of root development through auxin signaling pathways.

Purpose of the Study:

• To investigate the role of the transcription factor ZmARF1 in maize's response to low inorganic phosphate (Pi) stress.
• To elucidate the molecular mechanisms by which ZmARF1 influences root morphology and phosphate tolerance.

Main Methods:

• Gene expression analysis (transcriptomics) to identify downstream targets.
• Gene knockout and overexpression studies in maize.
• Transcriptional activation assays to confirm direct binding and activation.

Main Results:

• ZmARF1 overexpression enhanced root morphology and phosphate stress tolerance.
• ZmARF1 directly activates the expression of ZmLBD1, a gene involved in lateral root development.
• ZmARF1 positively regulates key Pi transporters (ZmPHR1, ZmPHT1;2, ZmPHO2) and ZmERF2 represses ZmARF1.

Conclusions:

• ZmARF1 is a crucial regulator of root development and phosphate homeostasis in maize.
• ZmARF1 confers low-Pi stress tolerance by modulating lateral root formation and Pi uptake.
• ZmARF1 acts as a central node integrating auxin signaling with phosphate starvation responses.