A high tocopherol content rice cultivar ‘Tocomi-1’

다국어 초록 (Multilingual Abstract)

‘Tocomi-1’, a new japonica rice cultivar derived from a 200 Gy gamma ray irradiation with high tocopherol content and red pericarp. The local adaptability test of MRXII-1001-1 was carried out from 2012 to 2014 and it was named as ‘Tocomi-1’ in 2014. This variety is medium matured with heading date of August 12 in honam plain area of Korea. This variety is about 80 cm tall culm length and 106 spikelets per panicle. Its 1,000 grain-weight of rice seeds is 25.4 g. The yield potential of this variety is about 5.15 MT/ha in local adaptability test for three years. This variety exhibited greater seed longevity than the Donganbyeo, indicating a crucial role for tocopherols in maintaining viability during quiescence, and displayed faster seedling growth during the early growth stage. Tocopherol contents was 50% higher than the Donganbyeo. To study the molecular mechanism underlying vitamin E biosynthesis, we examined the expression patterns of seven rice genes encoding vitamin E biosynthetic enzymes. Accumulation levels of the OsVTE2 transcript and OsVTE2 protein in the ‘Tocomi-1’ were significantly higher than in the Donganbyeo. Sequence analysis revealed that the ‘Tocomi-1’ harbored a point mutation in the OsVTE2 promoter region, which resulted in the generation of MYB transcription factor—binding cis-element. These results help identify the promoter regions that regulate OsVTE2 transcription, and offer insights into the regulation of tocopherol content in ‘Tocomi-1’.