Buckwheat in Tissue Culture Research: Current Status and Future Perspectives

Buckwheat is a member of a genus of 23 species, where the two most common species are Fagopyrum esculentum (common buckwheat) and Fagopyrum tataricum (Tartary buckwheat). This pseudocereal is a source of micro and macro nutrients, such as gluten-free proteins and amino acids, fatty acids, bioactive compounds, dietary fibre, fagopyrins, vitamins and minerals. It is gaining increasing attention due to its health-promoting properties. Buckwheat is widely susceptible to in vitro conditions which are used to study plantlet regeneration, callus induction, organogenesis, somatic embryogenesis, and the synthesis of phenolic compounds. This review summarises the development of buckwheat in in vitro culture and describes protocols for the regeneration of plantlets from various explants and differing concentrations of plant growth regulators. It also describes callus induction protocols as well as the role of calli in plantlet regeneration. Protocols for establishing hairy root cultures with the use of Agrobacterium rhizogens are useful in the synthesis of secondary metabolites, as well as protocols used for transgenic plants. The review also focuses on the future prospects of buckwheat in tissue culture and the challenges researchers are addressing.

Dicentrine Production in Callus and Cell Suspension Cultures of Stephania Venosa

The highest dicentrine content (19.5 ± 0.3 mg/g dry weight) from callus culture of Stephania venosa was achieved from stem segments cultured on MS medium supplemented with TDZ 0.5 mg/L and NAA 1.0 mg/L. Cell suspension cultures were established from callus cultured on MS liquid medium with the same plant growth regulators. Dicentrine production from S. venosa cell suspension cultures was obtained in the range of 15–26 mg/g dry weight. Elicitation in cell suspension cultures by chitosan (50 mg/L) and salicylic acid (2 mg/L) for 6 days significantly increased dicentrine content. Our findings indicate that callus and cell suspension cultures of S. venosa can produce high levels of dicentrine as an alternative source of plant materials.

The multiplicity of hairy root cultures: prolific possibilities

Hairy root cultures (HRCs), induced by Agrobacterium rhizogenes infection, have been established from a wide variety of plant species. HRCs accumulate phytochemicals to levels comparable to that of intact plants and are usually stable in their biosynthetic capacity. When optimized for liquid cultures, hairy roots can be grown in industrial-scale bioreactors providing a convenient, abundant and sustainable source of phytochemicals. Due to their ease of propagation and growth in confined environments, HRCs have also been used in recent years in the synthesis of recombinant therapeutic proteins, especially those that have been challenging to express in bacteria, yeast and mammalian expression systems. Although phytochemicals are recognized for their important roles in plant and human health, large gaps still exist in understanding how phytochemicals (in particular, secondary/specialized metabolites) are synthesized in plants. This review presents recent developments and findings in phytochemical and recombinant protein production, as well as new revelations in gene discovery and biochemical pathway elucidation, by the utilization of HRCs. Although many challenges still exist for industrial applications of HRCs, the immediate future of this diverse system, especially for the bench-side scientists, is still found to be promising and abounding in possibilities.