Synergistic Effects of Plant Growth Regulators and Elicitors on α-Humulene and Zerumbone Production in Zingiber zerumbet Smith Adventitious Root Cultures

Integrating transcriptome and metabolome to explore the growth-promoting mechanisms of GABA in blueberry plantlets

Tissue culture technology is the main method for the commercial propagation of blueberry plants, but blueberry plantlets grow slowly and have long growth cycles under in vitro propagation, resulting in low propagation efficiency. In addition, the long culturing time can also result in reduced nutrient content in the culture medium, and the accumulation of toxic and harmful substances that can lead to weak growth for the plantlets or browning and vitrification, which ultimately can seriously reduce the quality of the plantlets. Gamma-aminobutyric acid (GABA) is a four-carbon non-protein amino acid that can improve plant resistance to various stresses and promote plant growth, but the effects of its application and mechanism in tissue culture are still unclear. In this study, the effects of GABA on the growth of in vitro blueberry plantlets were analyzed following the treatment of the plantlets with GABA. In addition, the GABA-treated plantlets were also subjected to a comparative transcriptomic and metabolomic analysis. The exogenous application of GABA significantly promoted growth and improved the quality of the blueberry plantlets. In total, 2,626 differentially expressed genes (DEGs) and 377 differentially accumulated metabolites (DAMs) were detected by comparison of the control and GABA-treated plantlets. Most of the DEGs and DAMs were involved in carbohydrate metabolism and biosynthesis of secondary metabolites. The comprehensive analysis results indicated that GABA may promote the growth of blueberry plantlets by promoting carbon metabolism and nitrogen assimilation, as well as increasing the accumulation of secondary metabolites such as flavonoids, steroids and terpenes.

Zingiber zerumbet (L.) Roscoe ex Sm.: biotechnological advancements and perspectives

Shampoo ginger (Zingiber zerumbet) is a multipurpose ginger that has confirmed their role as food, medicine, and for decorative purposes. The rhizome possesses zerumbone, curcuminoids, and other bioactive molecules that play crucial roles in treating several human diseases. To date, several reports are existing on the in vitro biotechnology of Z. zerumbet. The present review highlights the consolidated clarification and comprehensive explanation of in vitro biotechnological implications based on plant tissue culture for the improvement of Z. zerumbet. Studies on biotechnological involvement in shampoo ginger were primarily emphasized in the study of the last 3 decades, for instance, in vitro regeneration, micro-rhizome production, callus culture, somatic embryogenesis, ex vitro establishment, and molecular assessment of in vitro-raised clones. Moreover, this review provides insights into different in vitro culture systems and endophytes involvement in the production of secondary metabolites. This review will assist for advanced research areas related to in vitro manipulation of shampoo ginger, especially for the commercial cultivation of secondary metabolites rich clones of Z. zerumbet. Moreover, it will provide an insight into crop upgrading and breeding programs of this underutilized, aromatic, and medicinal plant for amended yield and quality. KEY POINTS: • Z. zerumbet is an aromatic spice and an ornamental • This review comprehensively assesses Z. zerumbet tissue culture • Key shortcomings and future directions of Z. zerumbet biotechnology.

Healthy Zerumbone: From Natural Sources to Strategies to Improve Its Bioavailability and Oral Administration

Zerumbone is a multifunctional compound with antimicrobial, antitumor, hyperalgesic, antioxidant and anti-inflammatory applications, and constitutes a point molecule for the future synthesis of derivatives with improved efficiency. This monocyclic sesquiterpenoid is found in high content in wild ginger (Zingiber zerumbet Smith), a perennial herb with economic importance as an ornamental as well as a medicinal plant. The presence of zerumbone is a distinctive feature that allows identification and differentiation from other species, not only in Zingiber, but also in Curcuma, Alpinia, Boesenbergia, Ethlingera and Ammomum spp., as well as related families (Costaceaee). To successfully use zerumbone in areas such as medicine, food and agriculture, further research on improving its low solubility and bioavailability, as well as its preservation, is a major current priority. In addition, despite its promising pharmacological activities, preclinical and clinical studies are required to demonstrate and evaluate the in vivo efficacy of zerumbone.