Root Epidermal Cell Patterning Is Modulated by a Critical Residue in the WEREWOLF Transcription Factor

Area of Science:

• Plant Biology
• Developmental Biology
• Genetics

Background:

• The Arabidopsis root epidermis displays a specific pattern of root-hair and nonhair cells.
• This pattern is controlled by a gene regulatory network involving the R2R3-type MYB transcription factor WEREWOLF (WER).

Purpose of the Study:

• To identify and characterize novel mutants affecting root epidermal cell patterning.
• To investigate the role of specific residues in the WER protein function.

Main Methods:

• Genetic enhancer screening to identify new mutants.
• Molecular characterization of the identified mutant (wer-4).
• Analysis of WER target gene expression and creation of WER variants.

Main Results:

• A novel mutant, wer-4, with an abnormal root-hair and nonhair cell pattern was identified.
• The wer-4 mutation results in a D105N substitution in the DNA-binding R3 MYB repeat of WER.
• This substitution differentially affects the transcription of key WER target genes, altering cell fate regulators.

Conclusions:

• The Asp-105 residue in WER is critical for its function in regulating downstream gene expression.
• Modulation of this residue impacts the gene regulatory network controlling root epidermal cell fate.
• Findings provide insights into WER protein function and its role in establishing plant root development patterns.