Decellularized small intestine submucosa (dSIS) is a promising biomaterial for promoting tissue regeneration. Isolated from the submucosal layer of animal jejunum, SIS is rich in extracellular matrix (ECM) proteins, including collagen, laminin, and fibronectin. Following mild decellularization, dSIS becomes an acellular matrix that supports cell adhesion, proliferation, and differentiation. Conventional dSIS matrix is usually obtained by thermal crosslinking, which yields a soft scaffold with low stability. To address these challenges, dSIS is modified with methacrylate groups for photocrosslinking into stable hydrogels. However, dSIS has not been modified with clickable handles for orthogonal crosslinking. Here, the development of norbornene‐modified dSIS, named dSIS‐NB, via reacting amine groups of dSIS with carbic anhydride in acidic aqueous reaction conditions is reported. Using triethylamine (TEA) as a mild base catalyst, high degrees of NB substitution on dSIS are obtained. In addition to describing the synthesis of dSIS‐NB, its adaptability in orthogonal hydrogel crosslinking for cancer and vascular tissue engineering is explored. Impressively, compared with physically crosslinked dSIS and collagen matrices, orthogonally crosslinked dSIS‐NB hydrogels supported rapid dissemination of cancer cells and superior vasculogenic and angiogenic properties. dSIS‐NB is also exploited as a versatile bioink for 3D bioprinting.

Northern Vietnam is one of the most important centers of genetic diversity for cultivated rice. Over thousands of years of cultivation, natural and artificial selection has preserved many traditional rice landraces in northern Vietnam due to its geographic situation, climatic conditions, and many ethnic groups. These local landraces serve as a rich source of genetic variation—an important resource for future crop improvement. In this study, we determined the genetic diversity and population structure of 79 rice landraces collected from northern Vietnam and 19 rice accessions collected from different countries. In total, 98 rice accessions could be differentiated into japonica and indica with moderate genetic diversity and a polymorphism information content of 0.382. Moreover, we found that genetic differentiation was related to geographical regions with an overall PhiPT (analog of fixation index F_ST) value of 0.130. We also detected subspecies-specific markers to classify rice (Oryza sativa L.) into indica and japonica. Additionally, we detected five marker-trait associations and rare alleles that can be applied in future breeding programs. Our results suggest that rice landraces in northern Vietnam have a dynamic genetic system that can create different levels of genetic differentiation among regions, but also maintain a balanced genetic diversity between regions.

Developing rice varieties with increased mineral element content is the most cost-effective and efficient approach for alleviating human malnutrition and nutrient deficiencies. In this study, quantitative trait loci (QTLs) were mapped for mineral element content in 96 introgression lines derived from a cross between the elite Korean Oryza sativa japonica cultivar “Hwaseong” and the wild rice Oryza rufipogon (IRGC105491). The population was grown in two locations, and Fe, Zn, Mn, and Ca contents of the brown rice were measured. Six QTLs were identified on chromosomes 6, 8, and 10, and all O. rufipogon alleles increased trait values. The positions of qFe10 and qZn10 were further defined; higher Fe and Zn contents are related to the 375-kb O. rufipogon segment between the markers RM1873 and RM25612. The combined analysis of the whole-genome sequencing data, spatiotemporal expression profile, and gene expression suggested that a transcription factor gene, namely the rice homeobox gene 9 (LOC_Os10g33960) marks as the high potential candidate associated with Fe and/or Zn regulation. This study provides valuable information on candidate genes qFe10 and qZn10 from O. rufipogon, which may be vital in developing rice varieties with increased Fe and/or Zn content without any penalty in traits of agronomic importance.

Creating a functional intestine model remains challenging owing to the complex topography of the intestinal crypt/villus structure. Here, an inverse molding biofabrication technique is presented to address this challenge. A sacrificial hydrogel mold (SHM) with negative crypt/villus features is first fabricated using digital light processing (DLP) 3D printing of poly(ethylene glycol)–norbornene–tyramine (PEGNB‐T) thiol–norbornene hydrogels. Next, decellularized small intestine submucosa–norbornene (dSIS–NB) solution is cast and photopolymerized over the SHM, also via efficient thiol–norbornene photoclick reaction using PEG‐tetrathiol as the crosslinker. The hydrogel construct is placed in a buffer solution to induce autonomous and rapid dissolution of the SHM, creating dSIS–NB hydrogels with the positive crypt/villus structure. Intestinal epithelial cells seeded on the dSIS–NB crypt/villus matrices form a confluent monolayer within 3 days and display correct intestinal polarity. Through transepithelial electrical resistance (TEER) measurements and macromolecular transport studies, the new inverse‐molded dSIS–NB crypt/villus model further demonstrates the selective and drug‐responsive barrier functions. Finally, the unique biofabrication technique is leveraged to create an intestinal disease model carrying regions of both healthy crypts–villi structure and flattened epithelium with hindered macromolecular transport.

Previously, five putative quantitative trait loci (QTLs) for low-temperature germination (LTG) have been detected using 96 BC₃F₈ lines derived from an interspecific cross between the Korean japonica cultivar “Hwaseong” and Oryza rufipogon. In the present study, two introgression lines, CR1517 and CR1518, were used as parents to detect additional QTLs and analyze interactions among QTLs for LTG. The F₂ population (154 plants) along with parental lines, Hwaseong and O. rufipogon, were evaluated for LTG and coleoptile length under low-temperature conditions (13 °C). Among five QTLs for LTG, two major QTLs, qLTG1 and qLTG3, were consistently detected at 6 and 7 days after incubation. Three minor QTLs were detected on chromosomes 8 and 10. Two QTLs, qLTG10.1 and qLTG10.2, showing linkage on chromosome 10, exerted opposite effects with the Hwaseong allele at qLTG10.2 and the O. rufipogon allele at qLTG10.1 respectively, in turn, increasing LTG. Interactions among QTLs were not significant, implying that the QTLs act in an additive manner. Near-isogenic line plants with the combination of favorable alleles from O. rufipogon and Hwaseong exhibited higher LTG than two introgression lines. With regard to coleoptile length, three QTLs observed on chromosomes 1, 3, and 8 were colocalized with QTLs for LTG, suggesting the pleiotropy of the single gene at each locus. According to the results, the introgression of favorable O. rufipogon alleles could hasten the development of rice with high LTG and high coleoptile elongation in japonica cultivars.

Phytophthora sojae is the causal agent of the Phytophthora root and stem rot in soybean, which has resulted in a significant increase in the incidence of the disease and substantial yield losses on a global scale. The proliferation of Phytophthora sojae can be mitigated through the development of Phytophthora-resistant soybean cultivars. A fundamental understanding of the genetic diversity and dynamic changes within the P. sojae population is essential for disease management and the development of new P. sojae-resistant varieties. Although a large number of pathogen samples can lead to more comprehensive interpretations and better conclusions, only six indigenous P. sojae isolates were available in the Republic of Korea at the time of the experiments. Due to the limited availability, this study preliminarily aimed to assess the pathotypes and genetic variation of the six P. sojae isolates collected in the Republic of Korea. The virulence patterns of all the six P. sojae isolates differed based on the 15 soybean differentials known for P. sojae resistance. The six isolates displayed high levels of pathotype complexities, ranging from 8 to 15, which is notably higher than those observed in other countries. Furthermore, 18 of the 21 simple sequence repeat markers used exhibited polymorphisms. The mean allele number (3.8) shows higher genetic variability compared to that (2.5) of isolates from the USA. The gene diversity (0.624) and the mean polymorphic information content (0.579) also displayed high levels of variation among the six isolates. A low mean heterozygosity (0.019) indicated a rare but possible outcrossing between the isolates, which was detected by the SSR marker PS07. Genetic dissimilarity assessments were employed to categorize the six P. sojae isolates into three groups using a neighbor-joining phylogenetic tree and principal component analysis. Although on a small scale, the phenotypic and genotypic assay results obtained indicated a significant variability in the pathotypes and genetic variation within the P. sojae isolates in the Republic of Korea. Though limited in scope, these results will be a cornerstone for elucidating the virulence pathotype and genetic diversity of the P. sojae population in future analyses. These findings also have the potential to improve the soybean breeding strategies aimed at enhancing resistance to P. sojae in the Republic of Korea.