Ferns: the missing link in shoot evolution and development

Area of Science:

• Plant biology
• Evolutionary developmental biology
• Genetics

Background:

• Shoot development mechanisms are primarily understood from angiosperms, the most recently diverged plant lineage.
• Angiosperm shoot development involves a layered apical meristem producing lateral organs.
• Non-seed plant shoots originate from single or small populations of apical cells, posing challenges for comparative studies.

Purpose of the Study:

• To compare and contrast shoot development across diverse land plant lineages.
• To highlight the evolutionary significance of monilophytes (ferns) as a phylogenetic midpoint.
• To explore the potential of Ceratopteris richardii as a model for studying shoot development evolution.

Main Methods:

• Comparative analysis of existing knowledge on shoot development in land plants.
• Review of developmental and molecular data from various plant lineages.
• Consideration of recent technical advances enabling transgenic analysis in ferns.

Main Results:

• Significant differences exist in shoot apical organization between angiosperms and non-seed plants.
• Monilophytes offer a crucial phylogenetic perspective for understanding shoot development evolution.
• Ceratopteris richardii is emerging as a tractable model for genetic studies in ferns.

Conclusions:

• Understanding shoot development evolution requires examining diverse plant lineages beyond angiosperms.
• Ferns, particularly Ceratopteris richardii, are vital for deciphering the genetic basis of shoot development.
• Comparative studies are essential for reconstructing the evolutionary history of plant form and genetic regulation.