Evolution of plant p-type ATPases

Area of Science:

• Plant molecular biology
• Evolutionary genomics
• Biochemistry

Background:

• P-type ATPases are crucial membrane proteins involved in ion transport.
• Understanding their evolution in plants provides insights into cellular homeostasis and adaptation.
• The Viridiplantae (green plants) encompass diverse lineages with sequenced genomes.

Purpose of the Study:

• To inventory and compare P-type ATPase gene content across major green plant branches.
• To investigate the evolutionary patterns of sodium (Na+) and hydrogen (H+) pumps within Viridiplantae.
• To identify unique features of H+-ATPases in vascular plants.

Main Methods:

• Comparative genomic analysis of P-type ATPase genes.
• Selection of five representative Viridiplantae species with complete genome sequences: Ostreococcus tauri, Chlamydomonas reinhardtii, Physcomitrella patens, Selaginella moellendorffii, and Arabidopsis thaliana.
• Bioinformatic analysis of gene families and protein domains.

Main Results:

• All five analyzed species possess genes for all five P-type ATPase subfamilies.
• Chlorophytes exhibit co-existing Na+ (P2C, P2D) and H+ pumps, unlike flowering plants and animals.
• Vascular plant H+-ATPases possess a C-terminal regulatory domain and a conserved Arg residue, suggesting enhanced gradient formation and regulation.

Conclusions:

• The complete inventory of P-type ATPases in Viridiplantae is established.
• Early plant lineages show distinct evolutionary trajectories for ion transport mechanisms compared to vascular plants.
• Structural features of vascular plant H+-ATPases indicate sophisticated regulation for ion gradients.