In order to adapt to various environmental stresses, plants have employed diverse regulatory mechanisms of gene expression. Epigenetic changes, such as DNA methylation and histone modifications play an important role in gene expression regulation under stress condition. It has been known that some of epigenetic modifications are stably inherited after mitotic and meiotic cell divisions, which is known as stress memory. To understand molecular mechanisms underlying stress memory mediated by epigenetic modifications, we developed Arabidopsis suspension-cultured cell lines adapted to high salt by stepwise increases in the NaCl concentration up to 120 mM. Adapted cell line to 120 mM NaCl, named A120, exhibited enhanced salt tolerance compared to unadapted control cells (A0). Moreover, the salt tolerance of A120 cell line was stably maintained even in the absence of added NaCl, indicating that the salt tolerance of A120 cell line was memorized even after the stress is relieved. By using salt adapted and stress memorized cell lines, we intend to analyze the changes of DNA methylation, histone modification, transcriptome, and proteome to understand molecular mechanisms underlying stress adaptation as well as stress memory in plants.

Protein related parameters of pan bread and white salted noodles prepared from 26 Korean wheat cultivars and 6 commercial and imported wheat flours were evaluated to elucidate the relationship between rheological properties and end-use characteristics and to determine the effects of Glu-1 and Glu-3 alleles on those characteristics in Korean wheat cultivars. SDS-sedimentation volume based on protein weight was positively correlated with mixograph parameters and maximum height of dough and also positively correlated with bread loaf volume, crumb firmness and springiness of cooked noodles. Within Glu-1 loci, 1 or 2* subunit and 5 + 10 subunits showed longer mixingtime, higher maximum height of dough, and larger loaf volume than null allele, 2.2 + 12, and 2 + 12 subunits. Cultivars with 13 + 16 subunits at Glu-B1 locus showed higher protein content and optimum water absorption of mixograph than cultivars with 7 + 8 subunits. At Glu-3 loci, Glu-A3d showed longer mixing time than Glu-A3e, and Glu-B3d and Glu-B3h had stronger mixing properties than Glu-B3i. Glu-B3h had higher loaf volume and hardness of cooked noodles than Glu-B3d. Glu-D3a had lower protein content than Glu-D3c, and Glu-D3b showed stronger mixing properties than Glu-D3a. Glu-D3c showed lower hardness of cooked noodles than others.

Allelic variations in glutenin and puroindolines of Korean wheat cultivars evaluated to determine the effects of allelic variations on physico-chemical properties of flour and qualities of white salted noodles. In grain hardness and flour yield, Pinb-D1b had higher hardness index and flour yield than Pinb-D1a alleles. Glu-B1b and Glu-D1f also had lower hardness index than other alleles at the same locus and Glu-A1c, Glu-A3e and Glu-B3i alleles showed lower flour yield than other alleles. In flour compositions, Pina-D1b and Pinb-D1b showed higher particle size, ash and damaged starch content and lower lightness of wheat flour than Pina-D1a and Pinb-D1a. Glu-A1c, Glu-B1b, Glu-D1f, Glu-B3d and Glu-B3i showed lower particle size of flour than other alleles at Glu-1 and Glu-B3 locus. Korean wheats with Glu-B1f, Glu-D1a and Glu-B3b alleles had higher damaged starch content and lower lightness of flour than wheats other alleles at the same locus. Glu-B1b, Glu-D1f, Glu-B3d and Pina-D1a showed lower protein content and Glu-A1c, Glu-B1b, Glu-D1f Glu-B3d, Glu-B3i and Pinb-D1b showed lower SDS-sedimentation volume than other alleles. Hardness of cooked noodles ranked as Glu-A1a > Glu-A1c > Glu-A1c at Glu-A1 locus. Glu-B3h showed higher hardness of cooked noodles (5.10 N) than other alleles at Glu-B3 locus (< 4.66 N).