Three-dimensional reconstruction and multiomics analysis reveal a unique pattern of embryogenesis in Ginkgo biloba.

Ginkgo (Ginkgo biloba L.) is one of the earliest extant species in seed plant phylogeny. Embryo development patterns can provide fundamental evidence for the origin, evolution, and adaptation of seeds. However, the architectural and morphological dynamics during embryogenesis in G. biloba remain elusive. Herein, we obtained over 2,200 visual slices from 3 stages of embryo development using micro-computed tomography imaging with improved staining methods. Based on 3-dimensional (3D) spatiotemporal pattern analysis, we found that a shoot apical meristem with 7 highly differentiated leaf primordia, including apical and axillary leaf buds, is present in mature Ginkgo embryos. 3D rendering from the front, top, and side views showed 2 separate transport systems of tracheids located in the hypocotyl and cotyledon, representing a unique pattern of embryogenesis. Furthermore, the morphological dynamic analysis of secretory cavities indicated their strong association with cotyledons during development. In addition, we identified genes GbLBD25a (lateral organ boundaries domain 25a), GbCESA2a (cellulose synthase 2a), GbMYB74c (myeloblastosis 74c), GbPIN2 (PIN-FORMED 2) associated with vascular development regulation, and GbWRKY1 (WRKYGOK 1), GbbHLH12a (basic helix-loop-helix 12a), and GbJAZ4 (jasmonate zim-domain 4) potentially involved in the formation of secretory cavities. Moreover, we found that flavonoid accumulation in mature embryos could enhance postgerminative growth and seedling establishment in harsh environments. Our 3D spatial reconstruction technique combined with multiomics analysis opens avenues for investigating developmental architecture and molecular mechanisms during embryogenesis and lays the foundation for evolutionary studies of embryo development and maturation.

Genome-wide analyses of the GbAP2 subfamily reveal the function of GbTOE1a in salt and drought stress tolerance in Ginkgo biloba.

The APETALA2 (AP2) transcription factors play crucial roles in plant growth and stage transition. Ginkgo biloba is an important medicinal plant renowned for the rich flavonoid content in its leaves. In this study, 18 GbAP2s were identified from the G. biloba genome and classified into three clusters. We found that the members of the euAP2 cluster, including four TOEs (GbTOE1a/1b/1c/3), exhibited a higher expression level in most samples compared to other members. Specifically, GbTOE1a may have a positive regulatory role in salt and drought stress responses. The overexpression of GbTOE1a in G. biloba calli resulted in a significant increase in the flavonoid content and upregulation of flavonoid biosynthesis genes, including PAL, 4CL, CHS, F3H, FLSs, F3'Hs, OMT, and DFRs. By contrast, the silencing of GbTOE1a in seedlings decreased the flavonoid content and the expression of flavonoid synthesizing genes. In addition, the silenced seedlings exhibited decreased antioxidant levels and a higher sensitivity to salt and drought treatments, suggesting a crucial role of GbTOE1a in G. biloba salt and drought tolerance. To the best of our knowledge, this was the first investigation into the identification and characterization of GbAP2s in G. biloba. Our results lay a foundation for further research on the regulatory role of the AP2 family in flavonoid synthesis and stress responses.

The Jasmine (Jasminum sambac) Genome Provides Insight into the Biosynthesis of Flower Fragrances and Jasmonates.

Jasminum sambac (jasmine flower), a world-renowned plant appreciated for its exceptional flower fragrance, is of cultural and economic importance. However, the genetic basis of its fragrance is largely unknown. Here, we present the first de novogenome assembly of J. sambac with 550.12 Mb (scaffold N50 = 40.10 Mb) assembled into 13 pseudochromosomes. Terpene synthase (TPS) genes associated with flower fragrance are considerably amplified in the form of gene clusters through tandem duplications in the genome. Gene clusters within the salicylic acid/benzoic acid/theobromine (SABATH) and benzylalcohol O-acetyltransferase/anthocyanin O-hydroxycinnamoyltransferases/anthranilate N-hydroxycinnamoyl/benzoyltransferase/deacetylvindoline 4-O-acetyltransferase (BAHD) superfamilies were identified to be related to the biosynthesis of phenylpropanoid/benzenoid compounds. Several key genes involved in jasmonate biosynthesis were duplicated, causing an increase in copy numbers. In addition, multi-omics analyses identified various aromatic compounds and many genes involved in fragrance biosynthesis pathways. Furthermore, the roles of JsTPS3 in ß-ocimene biosynthesis, as well as JsAOC1 and JsAOS in jasmonic acid biosynthesis, were functionally validated. The genome assembled in this study for J. sambac offers a basic genetic resource for studying floral scent and jasmonate biosynthesis, and provides a foundation for functional genomic research and variety improvements in Jasminum.

Teachers' psychological resistance to digital innovation in jordanian entrepreneurship and business schools: Moderation of teachers' psychology and attitude toward educational technologies.

The current study aimed to highlight the factors that may influence teachers' psychological resistance to digital technologies in entrepreneurship and business schools. Theoretically grounded in the diffusion of innovations theory and the theory of planned behavior, the current research investigates teachers' psychological resistance to digital innovation, school culture and climate, and moderation of teacher attitudes toward educational technologies. A cross-sectional field survey of 600 business and entrepreneurship school teachers was conducted in Jordan. In this study, partial least square-structural equation modeling (PLS-SEM) was used to assess the variables' "direct and moderating impacts" using the Smart PLS software 3.0. According to the results, school culture and school innovation climate had a considerable positive impact on teachers' resistance to digital innovation. Additionally, teachers' attitudes toward educational technologies moderated the relationship between study constructs in the framework. The study is a significant advance to the literature related to entrepreneurship, business education, and digital innovation. Several key policy insights and recommendations for further research, as well as theoretical and practical implications, are suggested.

A three wave longitudinal study of school innovation climate and entrepreneurship teachers' acceptance to technology: Moderating role of knowledge sharing and knowledge hiding.

Entrepreneurship and business school teachers must extensively use technological and innovative tools to increase the efficacy of their instructional methods. This research aimed to investigate the teachers' acceptance of technology in the school innovation climate, to enhance the use and effectiveness of educational technology in Thai entrepreneurship and business schools. Furthermore, the conditional influence of knowledge hiding and sharing on the link between school innovation climate and educational technology has been investigated and reported. Using a longitudinal study design data were gathered from the 204 entrepreneurship teachers of six different universities in Pattani, Bangkok, and Songkla Provinces, Thailand. Based on SamrtPLS 3.3.3 analysis, results revealed that the "school innovation climate" positively impacts educational technology use. Additionally, knowledge hiding and sharing moderated the relationship between "school innovation climate" and acceptance of educational technology (actual use of educational technology, perceived usefulness, and perceived ease of educational technology). Current research attempted to bridge the gap between knowledge management and innovation theories application in entrepreneurship education. The study brings key policy implications for school leaders and practitioners and suggests several directions for future research.

Embryo transcriptome and miRNA analyses reveal the regulatory network of seed dormancy in Ginkgo biloba.

Seed dormancy is crucial for plant survival and prevents seed germination out of season. However, little is known about the regulatory mechanism of morphophysiological seed dormancy. Ginkgo biloba L. is one of the most ancient gymnosperms, and the completion of seed germination in this species requires cold and moist stratification. Here, we observed that at the mature seed stage, the embryo was not fully developed in G. biloba seeds. During dormancy stages, the length and weight of the embryo significantly increased, and nutrients accumulated in cotyledons. We further found that abscisic acid (ABA), gibberellic acid (GA), cytokinin and ethylene were integrated in the seed dormancy induction, maintenance and release processes, and GA biosynthesis and signaling transduction specifically act on dormancy release. Combining mRNA and miRNA analyses, we demonstrated that miRNA156 is involved in the regulation of morphophysiological dormancy. Our analyses revealed that G. biloba seed dormancy belongs to the ancestral morphophysiological dormancy type, which is not only regulated by the balance of ABA/GA, but also by other hormones associated with embryo morphological development, as well as genes related to embryo differentiation and development. These findings helped with elucidating the comprehensive regulatory network of morphophysiological dormancy in tree seeds.

Physiological, Transcriptomic, and Metabolic Responses of Ginkgo biloba L. to Drought, Salt, and Heat Stresses.

Ginkgo biloba L. is highly adaptable and resistant to a range of abiotic stressors, allowing its growth in various environments. However, it is unclear how G. biloba responds to common environmental stresses. We explored the physiological, transcriptomic, and metabolic responses of G. biloba to short-term drought, salt, and heat stresses. Proline, H2O2, and ABA contents, along with CAT activity, increased under all three types of stress. SOD activity increased under salt and heat stresses, while soluble protein and IAA contents decreased under drought and salt stresses. With respect to metabolites, D-glyceric acid increased in response to drought and salt stresses, whereas isomaltose 1, oxalamide, and threonine 2 increased under drought. Piceatannol 2,4-hydroxybutyrate and 1,3-diaminopropane increased under salt stress, whereas 4-aminobutyric acid 1 and galactonic acid increased in response to heat stress. Genes regulating nitrogen assimilation were upregulated only under drought, while the GRAS gene was upregulated under all three types of stressors. ARF genes were downregulated under heat stress, whereas genes encoding HSF and SPL were upregulated. Additionally, we predicted that miR156, miR160, miR172, and their target genes participate in stress responses. Our study provides valuable data for studying the multilevel response to drought, salinity, and heat in G. biloba.

Coexpression of TorD enhances the transport of GFP via the TAT pathway.

Twin-arginine translocation (Tat) pathway is capable of secreting fully folded proteins into the periplasm of Gram-negative bacteria and may thus be an ideal system for the expression of active cofactor-containing proteins. However, the applications of Tat system for such purpose have been plagued by low translocation efficiencies. In this study, we demonstrate that the coexpression of a soluble chaperone, TorD, in conjunction with the TorA signal peptide, the translocation efficiency of GFP can be enhanced by more than three-fold. The enhancement in translocation efficiency is believed to be a result of reduced proteolysis mediated by the binding of TorD toward the TorA signal peptide. We believe this approach can be further exploited for the expression and secretion of other heterologous proteins as well as traditional Tat substrate proteins.