GL1

GL1 generally refers to GLABROUS1, a gene in Arabidopsis thaliana. It encodes a transcription factor of the R2R3-MYB family that promotes the formation of trichomes (hair-like structures) on leaves and stems. In the trichome development pathway, GL1 functions together with TTG1 (a WD40-repeat protein) and GL3 (a bHLH transcription factor) to form a regulatory complex that activates downstream targets such as GL2.

The activity of GL1 leads to epidermal cells differentiating into trichomes; loss-of-function gl1 mutants are glabrous, lacking trichomes on leaves and stems. Overexpression or gain-of-function can increase or alter trichome density. GL1 expression is highest in developing aerial tissues where trichomes form, and its regulation is influenced by developmental cues and environmental conditions.

Genetic and evolutionary notes: GL1 is a well-studied model for plant cell fate decisions. Homologs exist in other plant species, indicating a conserved role in pubescence and hair patterning. Research on GL1 has contributed to understanding transcription factor networks that control epidermal cell differentiation and surface properties in plants.

Usage note: GL1 most commonly refers to GLABROUS1 in Arabidopsis genetics; in other contexts, GL1 may denote different genes or terms depending on the organism or field. If a text uses GL1 without context, disambiguation is required.