Secondary Metabolites in Shoot Cultures of Hypericum 10 Ana Coste, Carmen Pop, Adela Halmagyi, and Anca Butiuc-Keul Contents 1 Introduction .................................................................................. 275 2 Pharmaceutical Value of Hypericum Species ............................................... 276 3 Biotechnological Approaches to Improve Secondary Metabolite Production in Shoot Cultures of Hypericum Species ................................................... 277 3.1 Plant Growth Regulators and Signaling Compounds ................................ 278 3.2 Elicitation .............................................................................. 291 3.3 Precursor Feeding ..................................................................... 294 3.4 Genetic Transformation ............................................................... 294 4 Other Factors Affecting Secondary Metabolite Yield in Shoot Cultures of Hypericum Species ....................................................................... 295 4.1 Culture System ........................................................................ 296 4.2 Genotype and Ploidy Level ........................................................... 296 4.3 Developmental Stage .................................................................. 298 5 Conclusions .................................................................................. 298 References ....................................................................................... 299 All authors made equal contribution in this work and are equally considered as first authors. A. Coste (*) · A. Halmagyi Department of Experimental Biology and Biochemistry, Institute of Biological Research Cluj-Napoca, Cluj-Napoca, Rom^ ania e-mail: ana.coste@icbcluj.ro; adela.halmagyi@icbcluj.ro C. Pop (*) Department of Drug Industry and Pharmaceutical Biotechnology, Faculty of Pharmacy, University of Medicine and Pharmacy “Iuliu Haţieganu” Cluj-Napoca, Cluj-Napoca, Rom^ ania e-mail: carmen.pop@umfcluj.ro A. Butiuc-Keul Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Rom^ ania e-mail: anca.keul@ubbcluj.ro © Springer Nature Switzerland AG 2021 K. G. Ramawat et al. (eds.), Plant Cell and Tissue Differentiation and Secondary Metabolites, Reference Series in Phytochemistry, https://doi.org/10.1007/978-3-030-30185-9_9 273