Cryopreservation is considered the safe and efficient strategy for the long-term conservation of embryogenic cultures. The objective of this study was to cryopreserve the embryogenic tissues of hybrid larch to overcome the result raised by rapid growth rates of conifer embryogenic cultures necessitating frequent sub-culturing. We systematically evaluated several parameters, including the pre-culture method (liquid or solid), osmoprotectant type (DMSO, sucrose, or PEG6000), duration of cryoprotection (1–3 h), and thawing temperature (4 °C, 25 °C, or 40 °C). After one month of cryopreservation, we assessed the regeneration efficiency and maturation ability of both cryo-preserved and non-cryopreserved tissues. Our optimized protocol involves pre-culturing embryonic tissue on the solid medium with 0.4 M sorbitol for 48 h, followed by treatment with 10% DMSO, 0.4 M sucrose, and 15% PEG6000 for 1 h on ice, and immersion in liquid nitrogen with rapid thawing at 40 °C. Notably, the use of solid media during pre-culturing was crucial to enhancing the success rate of cryopreservation. Using protocol optimization, we achieved high embryogenic tissue survival rates of over 80% without affecting the ability of somatic embryogenesis. This work provides a comprehensive set of steps for routine cryopreservation of embryogenic tissues for long-term conservation in hybrid larch, along with sample protocols for cryopreservation of larch. The results demonstrate that vitrification is a reliable method for preserving embryogenic tissues of hybrid larch with broader implications for the cryopreservation of other plant species. Further optimization and standardization of protocols across different species would ensure the preservation of genetic diversity and facilitate future research in plant biotechnology that benefits human health, food security, and environmental sustainability.

NF-YB, a subfamily of Nuclear Factor Y (NF-Y) transcription factor, play crucial role in many biological processes of plant growth and development and abiotic stress responses, and they can therefore be good candidate factors for breeding stress-resistant plants. However, the NF-YB proteins have not yet been explored in Larix kaempferi, a tree species with high economic and ecological values in northeast China and other regions, limiting the breeding of anti-stress L. kaempferi. In order to explore the roles of NF-YB transcription factors in L. kaempferi, we identified 20 LkNF-YB family genes from L. kaempferi full-length transcriptome data and carried out preliminary characterization of them through series of analyses on their phylogenetic relationships, conserved motif structure, subcellular localization prediction, GO annotation, promoter cis-acting elements as well as expression profiles under treatment of phytohormones (ABA, SA, MeJA) and abiotic stresses (salt and drought). The LkNF-YB genes were classified into three clades through phylogenetic analysis and belong to non-LEC1 type NF-YB transcription factors. They have 10 conserved motifs; all genes contain a common motif, and their promoters have various phytohormones and abiotic stress related cis-acting elements. Quantitative real time reverse transcription PCR (RT-qPCR) analysis showed that the sensitivity of the LkNF-YB genes to drought and salt stresses was higher in leaves than roots. The sensitivity of LKNF-YB genes to ABA, MeJA, SA stresses was much lower than that to abiotic stress. Among the LkNF-YBs, LkNF-YB3 showed the strongest responses to drought and ABA treatments. Further protein interaction prediction analysis for LkNF-YB3 revealed that LkNF-YB3 interacts with various factors associated with stress responses and epigenetic regulation as well as NF-YA/NF-YC factors. Taken together, these results unveiled novel L. kaempferi NF-YB family genes and their characteristics, providing the basic knowledge for further in-depth studies on their roles in abiotic stress responses of L. kaempferi.

No abstract

No abstract

Background Risk factors and consequences associated with Clostridioides difficile infection (CDI) in children and adolescents with inflammatory bowel disease (IBD) are still uncertain. We conduct a systematic review and meta-analysis to assess risk factors and outcomes associated with CDI in children and adolescents with IBD. Methods PubMed, EMBASE and Cochrane Library databases were searched from inception to 24th February, 2021. Studies investigating risk factors, bowel surgery rate in pediatric IBD patients with and without CDI were included. Random-effects model was used for calculating summary estimates. Newcastle-Ottawa scale (NOS) was used for quality assessment. Results Fourteen studies, comprising 17,114 patients, were included. There was a significant association between 5-aminosalicylic acid (5-ASA) use and CDI [odds ratio (OR) = 1.95, 95% confidence interval (CI) 1.26-3.03], with minimal heterogeneity (I 2 = 0.00%). Increased risk of active disease (OR = 4.66, 95% CI 2.16-10.07) were associated with CDI in those studies performed in high quality score (NOS > 6) and significantly higher CDI rates in studies conducted outside USA (OR = 2.94, 95% CI 1.57-5.58). The bowel surgery rate in IBD with CDI was 3.8-57.1%, compared to that in IBD without CDI (0-21.3%). All studies were of moderate to high quality. Conclusions 5-ASA use and active disease might be risk factors associated with CDI in children and adolescents with IBD. Bowel surgery rates associated with CDI in IBD patients varied greatly. Large-scale clinical studies on CDI in children and adolescents with IBD are still needed to verify risk factors and outcomes.