In a laboratory in Morocco, scientists gently apply extracts from crustacean shells to a cluster of plant cells, triggering a five-fold increase in valuable antioxidants—all without harming a single plant. This is the quiet revolution of plant cell technology.
For centuries, humanity has relied on whole plants harvested from fields to obtain essential medicines, colors, and fragrances. Many of these compounds are produced by plants in minuscule quantities, requiring vast amounts of land and resources while being vulnerable to climate, pests, and political instability.
Increase in antioxidants achieved through elicitation techniques
Plants harmed in the process of phytochemical production
Controlled environment eliminates field cultivation unpredictability
Plant Cell, Tissue and Organ Culture (PCTOC) comprises a suite of sterile techniques for growing plant materials in controlled laboratory conditions, independent of the outside environment 1 . This approach provides a consistent, renewable, and scalable platform for phytochemical production that eliminates the unpredictability of field-based cultivation 1 .
Undifferentiated plant cells grown on solid media, often serving as the starting material for establishing other culture systems 1 . These masses of cells can be induced to produce specific compounds through strategic manipulation.
Friable callus tissues transferred to liquid media and constantly agitated, offering a homogeneous system suitable for large-scale metabolite production in bioreactors 1 . This system allows for easy application of compounds that can boost production.
Roots transformed by Agrobacterium rhizogenes that grow rapidly without hormones and are particularly stable in producing root-specific compounds 1 . These genetically uniform root systems represent an exceptionally reliable production platform.
Non-transformed roots induced by plant hormones that can demonstrate faster and greater production of certain compounds compared to cell suspensions 1 . These have been successfully scaled up to bioreactor level for several medicinal species.
The transition from small-scale laboratory cultures to industrial production represents a significant challenge, but advances in bioreactor technology are making large-scale plant cell culture increasingly feasible and economically viable 1 .
While culture optimization can significantly boost production, genetic engineering offers more precise and permanent solutions for enhancing phytochemical yields.
Many secondary metabolites are produced through tightly regulated biosynthetic pathways. Scientists can manipulate the transcription factors that control these pathways—such as the MYB, bHLH, and WD40 proteins that form regulatory complexes—to enhance the expression of multiple genes in a pathway simultaneously 3 8 .
The revolutionary CRISPR-Cas9 system enables precise modification of plant genomes 4 8 . By introducing the bacterial Cas9 nuclease and guide RNAs into plant cells, scientists can create targeted double-strand breaks in DNA . When repaired by the plant's error-prone non-homologous end joining pathway, these breaks often result in small insertions or deletions that can disrupt gene function .
Advanced genetic techniques now allow for the design of synthetic gene circuits, promoters, and regulatory elements that can fine-tune metabolic pathways 8 . By combining multiple genes from different organisms or creating entirely novel pathways, scientists can engineer plant cells to produce compounds they wouldn't naturally make, or to optimize the production of existing metabolites 8 .
A recent investigation into elicitation strategies provides an excellent case study of how simple treatments can dramatically enhance phytochemical production 6 .
Researchers working with Pelargonium graveolens (rose-scented geranium) callus cultures applied two different elicitors: chitosan (CHT), a natural derivative from crustacean shells, and salicylic acid (SA), a plant hormone involved in defense responses 6 . They tested various concentrations of both elicitors and analyzed the effects on phenolic and flavonoid production using LC-MS/MS analysis 6 .
The elicitor treatments significantly enhanced the production of valuable phenolic compounds, with particularly dramatic effects on certain flavonoids. The results demonstrated that different elicitors and concentrations could be optimized for specific target compounds.
| Treatment | Total Phenolic Content (mg/100g DW) | Total Flavonoid Content (mg/100g DW) |
|---|---|---|
| Control | 188.52 ± 6.81 | 54.71 ± 2.65 |
| SA2 (25 μM) | 336.80 ± 8.35 | 98.64 ± 6.58 |
| CHT5 (100 mg/mL) | 325.74 ± 7.81 | 90.42 ± 5.81 |
Source: Adapted from Elbouzidi et al., 2025 6
| Compound | Control (mg/100g DW) | SA2 (25 μM) | CHT5 (100 mg/mL) |
|---|---|---|---|
| Kaempferol | 103.68 ± 5.00 | 192.82 ± 17.99 | 119.68 ± 12.01 |
| Rutin | 14.62 ± 1.21 | 30.64 ± 3.00 | 18.35 ± 2.11 |
Source: Adapted from Elbouzidi et al., 2025 6
| Biological Activity | Control (IC₅₀, μg/mL) | SA2 (25 μM) | CHT5 (100 mg/mL) |
|---|---|---|---|
| DPPH Radical Scavenging | 68.90 ± 2.11 | 51.43 ± 1.31 | 58.72 ± 0.92 |
| Anti-tyrosinase Activity | 52.14 ± 4.42 | 35.42 ± 4.42 | 45.63 ± 3.51 |
| Anti-elastase Activity | 42.91 ± 1.60 | 31.84 ± 0.60 | 38.75 ± 1.21 |
Source: Adapted from Elbouzidi et al., 2025 6
This experiment demonstrates that strategic elicitation can dramatically enhance the production of specific valuable compounds while also improving their biological efficacy, offering a powerful yet relatively simple approach to optimizing plant cell cultures for industrial applications.
Creates targeted double-strand breaks in DNA, leading to gene knockouts or modifications . Used for targeted mutagenesis in Arabidopsis thaliana and crop plants to alter metabolic pathways 4 .
The implications of enhanced phytochemical production extend far beyond the laboratory. For conservation, PCTOC offers a sustainable alternative to wild harvesting of medicinal plants, many of which are endangered due to overcollection 1 . For global medicine supplies, it provides a buffer against the uncertainties of climate change, seasonal variations, and geopolitical disruptions that can affect traditional agriculture 1 7 .
Advances in bioreactor technology and process optimization are making large-scale plant cell culture increasingly feasible and economically viable 1 .
The convergence of plant cell culture, genetic engineering, and computational biology represents a fundamental shift in how we obtain valuable plant-derived compounds. In this new paradigm, the most potent pharmacies of the future may not be vast fields of plants, but rows of unassuming bioreactors filled with green cells working tirelessly to produce the compounds that sustain and heal us.