Jin-Baek Kim’s research while affiliated with Korea Atomic Energy Research Institute and other places

Wheat, a staple crop cultivated for over 8000 years, sustains more than 2.5 billion people globally, as a major source of carbohydrate, protein, fiber, and essential nutrients. Colored wheat, enriched with dietary fiber and antioxidants, offers valuable genetic resources for developing functional wheat varieties. Herein, a mutant pool of 1069 colored wheat lines was developed through gamma-ray irradiation to enhance genetic diversity. Mutant lines were classified into 10 groups based on seed color parameters (L*, a*, and b*), which were measured using the Hunter Lab system. K-means clustering categorized the mutant lines, and four representative lines from each group were analyzed for agronomic traits (plant height, spike length, thousand-seed weight, and kernels per spike) and antioxidant properties (radical-scavenging activity, ferric reducing antioxidant power, and total antioxidant capacity). Principal-component analysis revealed distinct clustering patterns, indicating associations between seed color, agronomic traits, and antioxidant activity. Darker seed color groups exhibited 3–16% higher levels of bioactive compounds and 10–18% higher antioxidant activities, whereas lighter groups showed 8–42% lower functional potential compared to the control wheat. These findings highlight the potential of mutation breeding in generating phenotypic diversity and developing wheat varieties with improved functional traits and bioactive compound content.

Cannabis (Cannabis sativa L.) is a unique crop producing cannabinoids, including Δ9-tetrahydrocannabinolic acid and cannabidiolic acid, which can transform into Δ9-tetrahydrocannabinol (THC) and cannabidiol through decarboxylation, but it is largely prohibited or strictly regulated in most countries because of the psychoactive effects of THC on humans. However, there has recently been increasing interest in cannabis because of clinical research, thus suggesting it has therapeutic effects. Because of its physiological properties and limited accessibility, ensuring homozygosity in cannabis is challenging. Most cannabis plants that are currently sold are hybrids. The SupwerowomanS1 cultivar was used to develop a new cultivar, document genetic variation, and identify a novel hemp mutant following self-pollination during polyploid breeding. A mutant with fewer axillary stems than SuperwomanS1 and round floral organs with many sugar leaves (like rosette leaves) was identified. A quantitative real-time PCR analysis indicated the expression levels of the main genes regulating axillary bud formation (SHOOT MERISTEMLESS, LATERAL SUPPRESSOR, REVOLUTA, WUSCHEL) were higher in the mutant than in SuperwomanS1. These findings may be relevant to hemp breeding and cultivation.

Cannabis ( Cannabis sativa L.) is a unique crop producing cannabinoids, including tetrahydrocannabinol (THC) and cannabidiols, but it is largely prohibited or strictly regulated in most countries because of the psychoactive effects of THC on humans. However, there has recently been increasing interest in cannabis because of clinical research suggesting it has therapeutic effects. Because of its physiological properties and limited accessibility, ensuring homozygosity in cannabis is challenging. Most cannabis plants that are currently sold are hybrids. The SupwerowomanS1 cultivar was used to develop a new cultivar, document genetic variation, and identify a novel hemp mutant following self-pollination during polyploid breeding. A mutant with fewer axillary stems than SuperwomanS1 and round floral organs with many sugar leaves (like rosette leaves) was identified. A quantitative real-time PCR analysis indicated the expression levels of the main genes regulating axillary bud formation ( SHOOT MERISTEMLESS , LATERAL SUPPRESSOR , REVOLUTA , WUSCHEL ) were higher in the mutant than in SuperwomanS1. These findings may be relevant to hemp breeding and cultivation.

Background Salinity is a major abiotic stress that prevents normal plant growth and development, ultimately reducing crop productivity. This study investigated the effects of salinity stress on two wheat lines: PL1 (wild type) and PL6 (mutant line generated through gamma irradiation of PL1). Results The salinity treatment was carried out with a solution consisting of a total volume of 200 mL containing 150 mM NaCl. Salinity stress negatively impacted germination and plant growth in both lines, but PL6 exhibited higher tolerance. PL6 showed lower Na ⁺ accumulation and higher K ⁺ levels, indicating better ion homeostasis. Genome-wide transcriptomic analysis revealed distinct gene expression patterns between PL1 and PL6 under salt stress, resulting in notable phenotypic differences. Gene ontology analysis revealed positive correlations between salt stress and defense response, glutathione metabolism, peroxidase activity, and reactive oxygen species metabolic processes, highlighting the importance of antioxidant activities in salt tolerance. Additionally, hormone-related genes, transcription factors, and protein kinases showed differential expression, suggesting their roles in the differential salt stress response. Enrichment of pathways related to flavonoid biosynthesis and secondary metabolite biosynthesis in PL6 may contribute to its enhanced antioxidant activities. Furthermore, differentially expressed genes associated with the circadian clock system, cytoskeleton organization, and cell wall organization shed light on the plant’s response to salt stress. Conclusions Understanding these mechanisms is crucial for developing stress-tolerant crop varieties, improving agricultural practices, and breeding salt-resistant crops to enhance global food production and address food security challenges.

FLOWERING LOCUS T (FT)-like genes play crucial and antagonistic roles in flowering induction in plants. We analyzed the functional and evolutionary characteristics of pepper FT-like genes. According to their similarity to an FT ortholog of tomato, 10 phosphatidylethanolamine-binding protein family genes were retrieved from the pepper genome. Phylogenetic analysis placed the proteins encoded by six of these genes (CaFT1-CaFT6) into an FT-like clade. Comparative genomic analysis showed that four of pepper FT-like genes (CaFT1, CaFT2, CaFT3, CaFT4) have orthologous counterparts in other three solanaceous crops (tomato, potato, and tobacco). CaFT5, which is unique to pepper, was inferred to have arisen by genomic rearrangement followed by duplication of CaFT2. Interestingly, CaFT6, which has been nominated as a pepper FT ortholog, was located in a genomic region not syntenic to the loci of FT orthologs in other crops and was clustered with two other FT-like genes. This result implies the involvement of a unique evolutionary process in the origin of CaFT6. Pepper FT-like genes were mostly expressed in leaves, and their protein products interacted with FLOWERING LOCUS D. When they were overexpressed in Arabidopsis, flowering was promoted by two genes (CaFT6 and CaFT4) and delayed by two others (CaFT1 and CaFT3). The expressions of CaFT6 and CaFT4 were also negatively related to flowering time in pepper accessions implying that they act as flowering promoter genes. The conserved and unique characteristics of pepper FT-like genes provide insights into the dynamic evolution of FT-like genes and useful information for manipulation of FT-like genes to improve the productivity.

Wheat (Triticum aestivum Linn.; Poaceae) is the second most cultivated food crop among all global cereal crop production. The high carbohydrate content of its grains provides energy, multiple nutrients, and dietary fiber. After threshing, a substantial amount of wheat hull is produced, which serves as the non-food component of wheat. For the valorization of these by-products as a new resource from which functional components can be extracted, the hull from the seeds of cultivated wheat mutant lines bred after γ-irradiation were collected. Untargeted metabolite analysis of the hull of the original cultivar (a crossbreeding cultivar., Woori-mil × D-7) and its 983 mutant lines were conducted using ultra-performance liquid chromatography–electrospray ionization quadrupole time-of-flight mass spectrometry technique. A total of 55 molecules were tentatively identified, including 21 compounds found in the Triticum species for the first time and 13 compounds not previously described. Among them, seven flavonolignans with a diastereomeric structure, isolated as a single compound from the hull of T. aestivum in our previous study, were used as the standards in the metabolite analysis. The differences in their collision cross-section values were shown to contribute to the clear distinction between tricine-lignan stereoisomers. To select functionally active agents with anti-inflammatory activity among the identified compounds, the wheat hull samples were evaluated for their inhibitory effect on nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. As a result of multivariate analysis based on the results of chemical and biological profiles of the wheat hull samples, 10 metabolites were identified as key markers, contributing to the distinction between active and inactive mutant lines. Considering that one of the four key markers attributed to anti-inflammatory activity has been identified to be a flavonolignan, the wheat hull could be a valuable source of diverse tricin-lignan type compounds and used as a natural health-promoting product in food supplements.

The concentration of phenolic compounds in rapeseed is important because they are either anti-nutritional compounds or directly related to antioxidant activity. In this study, single nucleotide polymorphisms (SNPs) were identified using genotyping-by-sequencing (GBS), and an association study was conducted to investigate phenolic content in 95 rapeseed mutant lines derived from gamma rays and their original cultivar. A total of 3,196,318 SNPs were detected, resulting in the identification of a set of 70,208 union SNPs used to perform association studies. Seven compounds were identified, sinapine being the major phenolic compound (91.2–99.2%) in all genotypes. An association study was conducted for seven compounds and total phenolic content (TPC). It identified 241 SNPs that were significantly associated with these compounds, total sinapine content (TSC), and TPC. Based on the SNP markers detected, BnaC02g20420D was associated with dihexose, BnaC08g30570D with progoitrin, BnaA01g06890D with methyl sinapate, BnaA09g16810D with sinapine(4-O-8′)guaiacyl, BnaCnng39930D with trans-sinapine 1, BnaA07g31720D with trans-sinapine 2, BnaC03g31950D with sinapoyl malate, and BnaAnng27700D with TPC. These were selected as candidate genes that may play a key role in rapeseed. The SNP markers associated with these key phenolic compounds can be used as targets in breeding programs to reduce anti-nutritional components.