The role of auxin-mediated gene activation in the bryophyte, Physcomitrium patens

Perception and response to the hormone auxin are critical to plant growth and development. Expression of auxin-response genes is tightly regulated via known mechanisms of both activation and repression. Across the plant lineage, auxin-response gene induction is performed by AUXIN-RESPONSE FACTOR (ARF), activating transcription factors. Conversely, AUXIN/INDOLE ACETIC ACID proteins repress expression. Studies of gain-of-function constitutive-repression lines and ARF loss-of-function mutants have advanced the field. Yet, there is a need for a comparative study of aberrant auxin-signaling mutants to understand the developmental consequences of constitutive repression versus the absence of auxin-mediated gene induction. Using CRISPR/Cas9 gene-editing tools, we mutated each activating ARF gene in the model bryophyte, Physcomitrium patens. The resulting septuple loss-of-function mutant line (arfasept) has severe developmental phenotypes and a diminished ability to respond to exogenous auxin. ..., , , # The role of auxin-mediated gene activation in the bryophyte, Physcomitrium patens

[https://doi.org/10.5061/dryad.prr4xgxz1](https://doi.org/10.5061/dryad.prr4xgxz1)

## Description of the data and file structure

### Files and variables

#### File: Mutant\_Sequences.zip

**Description:** Recovered mutant alleles from CRISPR/Cas9 mutagenesis (.ape files, readable via A Plasmid Editor (ApE)). Includes a flow chart (.pdf) that illustrates how the septuple mutants were generated.

#### File: Combined\_CellWallAngles.csv

**Description:** Cross wall angles, relative to the angle of growth, for moss protonemal cells studied in this work. Arranged by genotype. Units are degrees.

##### Variables

* genotype

#### File: Chl\_Content.csv

**Description:** Relative chlorophyll content after 21 days on medium +/- NAA supplementation. Tissue samples were soaked in methanol overnight, in the dark, at room temperature. Measured on a spectrophotometer. Reported values have been normalized to chloro...,