Harnessing γ-TMT Genetic Variations and Haplotypes for Vitamin E Diversity in the Korean Rice Collection

Area of Science:

• Plant genetics
• Nutritional biochemistry
• Agricultural science

Background:

• Gamma-tocopherol methyltransferase (γ-TMT) is crucial for vitamin E biosynthesis in rice.
• Tocochromanols, including tocopherols and tocotrienols, are vital for rice nutritional quality.
• Understanding γ-TMT genetic variation is key to improving rice nutritional profiles.

Purpose of the Study:

• To analyze genetic variants within the γ-TMT gene in Korean rice accessions.
• To investigate the association between γ-TMT haplotypes and vitamin E isomer profiles.
• To identify genetic resources for enhancing rice nutritional quality through breeding.

Main Methods:

• Sequencing of the γ-TMT gene in 475 Korean rice accessions.
• Identification and characterization of genetic variants (SNPs and InDels).
• Haplotype analysis and association studies with vitamin E isomer profiling.

Main Results:

• 177 genetic variants, including two functional SNPs, were identified in γ-TMT.
• Balancing selection signature observed in the indica group.
• 27 distinct haplotypes were identified, with varying distributions in cultivated and wild rice.
• Specific haplotypes (e.g., Hap_2) significantly correlated with altered levels of α-tocopherol, γ-tocopherol, and their tocotrienol counterparts in japonica and indica rice.

Conclusions:

• The genetic landscape of γ-TMT is diverse in Korean rice.
• Functional variants and specific haplotypes significantly modulate vitamin E composition.
• Findings provide valuable genetic markers for marker-assisted selection in rice breeding programs targeting enhanced nutrition.