Auxin-mediated developmental control in the moss Physcomitrella patens.

Area of Science:

• Plant Biology
• Developmental Biology
• Evolutionary Biology

Background:

• Auxin is a critical signaling molecule governing plant growth and development.
• Mosses, as early diverging plants, possess and respond to auxin.
• The model moss *Physcomitrella patens* provides insights into conserved auxin pathways.

Purpose of the Study:

• To review and discuss auxin-regulated development in mosses, focusing on *Physcomitrella patens*.
• To explore the evolutionary origins and conservation of auxin signaling networks.
• To understand auxin's role in the evolution of land plants.

Main Methods:

• Genome sequencing of *Physcomitrella patens* to identify auxin-related genes.
• Comparative analysis of auxin pathways in mosses and flowering plants.
• Literature review of studies on auxin function in early land plants.

Main Results:

• The *P. patens* genome encodes core auxin homeostasis, perception, and signaling proteins found in flowering plants.
• This suggests the auxin molecular network predates the divergence of mosses and flowering plants.
• Auxin regulates conserved developmental processes like organogenesis, branching, and cell dynamics in both lineages.

Conclusions:

• The auxin signaling network is ancient, present in the last common ancestor of mosses and flowering plants.
• Despite life cycle differences, auxin controls fundamental developmental processes across diverse plant lineages.
• Studying auxin in mosses offers crucial insights into the evolution of plant development and land plant origins.