Soybean (Glycine max (L.) Merr.) is one of the most important crops with economic value as a source of protein and vegetable oil for human food and animal feed. In recent years, rapidly developed genome editing techniques have shown widespread application prospects for gene function studies and for improving important agronomic traits in many crops. Therefore, it is important to establish a highly efficient method for protoplast isolation and transient expression systems in soybeans. In this study, we established an efficient method for protoplast isolation and its application to transient gene expression in Korean soybean cultivars. The protoplasts were isolated from leaves, epicotyls, hypocotyls, cotyledons, and etiolated hypocotyls using various combinations of enzyme mixtures. We found that high-quality and large amounts of protoplasts were isolated from the etiolated hypocotyls when incubated for 8 h under conditions of 0.5% cellulase, 0.5% pectinase, and 1% viscozyme. In addition, we observed a high transfection efficiency of green fluorescent protein using etiolated hypocotyl protoplasts. Taken together, our protoplast isolation and transfection method is highly efficient and can be used for gene function and molecular analysis to better understand the biological and physiological processes in soybean.

Amphidiploid Brassica juncea (AABB, 2n=36) contains the synthesized genome of the diploid ancestors of Brassica rapa (AA, 2n=20) and Brassica nigra (BB, 2n=16), proven the ‘triangle of U’ model. Varieties of the B. juncea include vegetables, oilseed crops, and medicinal plants in South Asia, China, and other regions. ‘Dolsangat’, one of the cultivars of B. juncea is widely used as the main ingredient for ‘KatKimchi’, a kind of Korean traditional food Kimchi. To develop an efficient polyploidization protocol of B. juncea, we used twenty accessions. Among them, we could induce the amphidiploid plants with 0.23% in natural. A successful of polyploidization, it is essential of chromosome doubling regent treatment of B. juncea. At first, we tried to colchicine treatment in the embryo stage and it was very harmful to the embryo and could get few plants. The second, we made the regeneration plants from embryo to rooting phase and shocked them in 0.34% colchicine contained distilled water. We could induce amphidiploid plants with a success rate of 63.4%. Also, we surveyed glucosinolate content and JB1, Alsami, and JD6 showed high total contents. These plants will use for genetic materials for breeding, genetic and molecular studies.

Salt stress is a significant factor limiting growth and productivity in crops. However, little is known about the response and resistance mechanism to salt stress in maize. The
objective
of this research was to develop an enhanced salt-tolerant silage maize by mutagenesis with gamma radiation. To generate gamma radiation-induced salt-tolerant silage maize, we irradiated a KS140 inbred line with 100 Gy gamma rays. Salt tolerance was determined by evaluating plant growth, morphological changes, and gene expression under NaCl stress. We screened 10 salt-tolerant maize inbred lines from 2,248 M₂ mutant populations and selected a line showing better growth under salt stress conditions. The selected 140RS516 mutant exhibited improved seed germination and plant growth when compared with the wild-type under salt stress conditions. Enhanced salt tolerance of the 140RS516 mutant was attributed to higher stomatal conductance and proline content. Using whole-genome re-sequencing analysis, a total of 328 single nucleotide polymorphisms and insertions or deletions were identified in the 140RS516 mutant. We found that the expression of the genes involved in salt stress tolerance, ABP9, CIPK21, and CIPK31, was increased by salt stress in the 140RS516 mutant. Our results suggest that the 140RS516 mutant induced by gamma rays could be a good material for developing cultivars with salt tolerance in maize.

High-density genetic linkage mapping is critical for undertaking marker-assisted selection and confirming quantitative trait loci, as well as helping to build pseudomolecules of genomes. We constructed a genetic map using 94 F₁ populations generated from the interspecific cross between Korean cultivar “Wonwhang” (Pyrus pyrifolia, NCBI BioSample SAMN05196235) and European cultivar “Bartlett” (Pyrus communis). We designed a total of 24,267 SSR markers based on the genome sequences of “Wonwhang” for this. To select the markers that are linked to the traits important in pear breeding programs, SSR-containing genomic sequences were subjected to nucleotide sequence homology searches, which resulted in 510 SSR markers with high similarity to genes encoding proteins with putative functions such as transcription factors, resistance proteins, flowering time, and regulatory genes. Of these, 70 markers showed polymorphisms in parents and segregating populations and were used to construct a genetic linkage map, together with the unpublished 579 SNPs obtained from genotyping by sequencing analysis. The genetic linkage map covered 3,784.2 cM and the average distance between adjacent markers was 5.8 cM. Seventy SSR markers were distributed across 17 chromosomes with more than one locus.