Min Jeong Hong1, Young Eun Jang1, Dong-Gun Kim1,2, Jung Min Kim1,3, Min-Kyu Lee1,3, Jin-Baek Kim1, Seok Hyun Eom4, Bo-Keun Ha3, Jae Il Lyu1, Soon-Jae Kwon1. 1. Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea. 2. Department of Life-Resources, Graduate School, Sunchon National University, Sunchon, Korea. 3. Division of Plant Biotechnology, Collage of Agriculture and Life Science, Chonnam National University, Gwangju, Korea. 4. Department of Horticultural Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, Korea.
Abstract
BACKGROUND: Soybean seeds contain 18-24% lipids, which are made up of 85% polyunsaturated fatty acids. Two of these (linoleic and linolenic acids) comprise essential fatty acids that are not synthesized in humans and animals. Linolenic acid plays a vital role in the maintenance of brain function and is a source of docosahexaenoic acid for retinal and nerve tissue, with its physiological functions being a focus of attention. RESULTS: We developed mutant soybean populations via gamma irradiation of Korean cultivars Danbaek and Daepung and evaluated the linolenic acid content of 78 and 154 M9 mutant progenies. We selected the four mutant lines with the highest linolenic acid contents based on 2 years of investigation of fatty acids. The selected mutant lines had linolenic acid contents that were 33.9% to 67.7% higher than those of the original cultivars and exhibited increased fatty acid desaturase (FAD) gene expression levels during seed development. We also identified nucleotide polymorphisms of FAD genes in the four mutant lines. CONCLUSION: The present study found that linolenic acid content is related to significantly increased expression levels of the FAD3C and FAD3D genes in the endoplasmic reticulum, which was uncovered by radiation mutation breeding of soybean.
BACKGROUND:Soybean seeds contain 18-24% lipids, which are made up of 85% polyunsaturated fatty acids. Two of these (linoleic and linolenic acids) comprise essential fatty acids that are not synthesized in humans and animals. Linolenic acid plays a vital role in the maintenance of brain function and is a source of docosahexaenoic acid for retinal and nerve tissue, with its physiological functions being a focus of attention. RESULTS: We developed mutant soybean populations via gamma irradiation of Korean cultivars Danbaek and Daepung and evaluated the linolenic acid content of 78 and 154 M9 mutant progenies. We selected the four mutant lines with the highest linolenic acid contents based on 2 years of investigation of fatty acids. The selected mutant lines had linolenic acid contents that were 33.9% to 67.7% higher than those of the original cultivars and exhibited increased fatty acid desaturase (FAD) gene expression levels during seed development. We also identified nucleotide polymorphisms of FAD genes in the four mutant lines. CONCLUSION: The present study found that linolenic acid content is related to significantly increased expression levels of the FAD3C and FAD3D genes in the endoplasmic reticulum, which was uncovered by radiation mutation breeding of soybean.