Tetratricopeptide Repeat 2 Is a Quantitative Trait Locus That Controls Seed Size

Area of Science:

• Plant genetics
• Molecular biology
• Agronomy

Background:

• Seed size is a crucial trait influencing plant evolution and crop productivity.
• The Seed Size QTL1 (SSQ1) locus in Arabidopsis thaliana accounts for significant variation in seed size.

Purpose of the Study:

• To identify the causal gene of the SSQ1 locus.
• To investigate the role of the identified gene in regulating seed size and biomass composition.

Main Methods:

• Genetic mapping and gene expression analysis to identify the SSQ1 causal gene.
• Quantitative trait analysis across different ecotypes and genetic backgrounds.
• Biomass composition analysis (oil, sucrose, protein) in transgenic lines and mutants.

Main Results:

• Tetratricopeptide Repeat Protein 2 (TPR2) was identified as the causal gene for the SSQ1 locus.
• Increased TPR2 gene dosage consistently increased seed mass and volume by 10-14%.
• TPR2 regulates seed size via maternal effects, altering sucrose and protein accumulation without affecting oil content.

Conclusions:

• TPR2 is a key maternal regulator of seed size in Arabidopsis thaliana.
• Understanding TPR2's function offers potential for improving crop yield through seed size manipulation.