Functional analysis of PsbS transmembrane domains through base editing in Physcomitrium patens

Area of Science:

• Plant Biology
• Molecular Biology
• Biochemistry

Background:

• Non-photochemical quenching (NPQ) is a vital photoprotective mechanism in plants, dissipating excess light energy as heat.
• NPQ regulation depends on the membrane protein PsbS, which interacts with antenna proteins to induce energy dissipation.
• Understanding PsbS function is crucial for enhancing plant fitness and crop productivity under fluctuating light conditions.

Purpose of the Study:

• To investigate the role of specific amino acid residues within transmembrane regions of PsbS in protein stability and function.
• To explore the impact of these residues on PsbS-antenna protein interactions and NPQ activity.
• To demonstrate the utility of base editing (BE) for in planta functional analysis of PsbS.

Main Methods:

• Utilized base editing (BE) technology in the model moss Physcomitrium patens.
• Introduced targeted amino acid substitutions in the PsbS protein in vivo.
• Assessed the effects of these mutations on PsbS stability, protein interactions, and NPQ activity.

Main Results:

• Identified specific amino acid residues critical for PsbS protein stability.
• Discovered a hydrophobic cluster of amino acids that significantly impacts PsbS activity.
• Provided insights into the molecular mechanisms governing PsbS function in NPQ.

Conclusions:

• Base editing is an effective tool for in planta gene function analysis in plants.
• Specific residues and hydrophobic clusters within PsbS transmembrane regions are essential for its photoprotective role.
• This research advances our understanding of NPQ regulation and its molecular basis.