Characterization of DWARF14 Genes in Populus

Area of Science:

• Plant Biology
• Molecular Genetics
• Hormone Signaling

Background:

• Strigolactones are plant hormones regulating shoot branching and symbiotic interactions.
• DWARF14 (D14) proteins perceive strigolactone signals in herbaceous plants.
• Knowledge of D14 genes in woody plants remains limited.

Purpose of the Study:

• Identify and characterize D14 homologs in the model woody plant, Populus trichocarpa (poplar).
• Determine the functional role of identified poplar D14 homologs in strigolactone signaling.

Main Methods:

• Bioinformatic analysis to identify D14 homologs in Populus trichocarpa.
• Gene expression analysis using quantitative PCR.
• Complementation assays in Arabidopsis d14 mutants.
• Amino acid alignment and protein structural modeling.

Main Results:

• Two D14 homologs, PtD14a and PtD14b, were identified in P. trichocarpa with high amino acid similarity (>95%).
• PtD14a transcript levels were generally higher than PtD14b.
• Only PtD14a successfully complemented Arabidopsis d14 mutants, indicating it is the functional ortholog.
• PtD14b exhibited amino acid substitutions in conserved regions, potentially affecting its function.

Conclusions:

• PtD14a is identified as the functional DWARF14 ortholog in Populus trichocarpa.
• Structural differences in PtD14b may explain its lack of function.
• This study provides a foundation for investigating strigolactone pathways in woody perennial plants.