Abscisic acid 농도에 따른 밀 종자의 발아와 단백질체의 발현 특성

Germination and Proteome Profile Characteristics of Wheat Seeds Treated under Different Concentrations of Abscisic Acid

This study was conducted to investigate the germination and proteome profile characteristics of wheat seeds treated under various concentrations of abscisic acid (ABA). After-ripening, the seeds of three wheat cultivars (Baegjoong, Keumkang, and Uri) showing different levels of dormancy were used. Germination index and germination rate of the cultivars was higher than 0.95% and 98%, respectively, and these were not significantly different under 0, 10, 30, and 50 μM ABA at 7 d after germination. However, the growth of the shoot and radicle was significantly inhibited at 10, 30, and 50 μM ABA compared to that at 0 μM ABA. Mean ABA content of the embryos of seeds germinated at 0 and 50 μM ABA for 7 d was 0.8 and 269.0 ngmg -1 DW, respectively. Proteins extracted from embryos germinated for 4 d were analyzed by two-dimensional gel electrophoresis, and proteins showing a difference of 1.5-fold or greater in their spot volume relative to that of 0 μM ABA were identified. The expression of four protein spots increased at 50 μM ABA and two protein spots were detected only at 50 μM ABA; these six proteins were all identified as globulin types. Conversely, the expression of three protein spots decreased at 50 μM ABA and were identified as cytosolic glutamine sysnthetase, isocitrate dehydrogenase, and S-adenosylmethionine synthetase 2. In conclusion, ABA did not inhibit the germination rate regardless of pre-harvest sprouting characteristics of the cultivars. However, the growth of the shoot and radicle was significantly inhibited by ABA, most likely through the down regulation of glutamine, methyl group donor, and polyamines biosynthesis, among others, while accompanied by globulin accumulation in the embryos.