FT-IR Mapping Unveils New Insights in Dahlia Root Composition

Dahlias are flowers that are known for their vibrant colors and can vary in size (1). Dahlias can be as small as two inches in diameter to up to 4 feet tall (1). For farmers, understanding the structural and chemical makeup of these flowers can aid them in producing dahlias that can thrive.

A recent collaborative study from researchers in Romania explored this topic. The study, published in Plants, examined how environmental and cultivation conditions can affect the chemical makeup of Dahlia roots (2). What makes this study unique is how the researchers applied Fourier transform infrared (FT-IR) spectroscopy in their work to learn more about how the distribution of key compounds—namely inulin, lignin, and suberin—varies across growth stages and cultivation conditions.

By understanding the Dahlia root’s composition, industries could develop Dahlia-based products. For instance, inulin-rich extracts could serve as dietary supplements, while suberin’s protective properties might inspire applications in eco-friendly packaging or as a raw material in cosmetics (2).

Beautiful Pink Dahlia Flower | Image Credit: © 200509313 - stock.adobe.com

Using FT-IR imaging, researchers tracked the biochemical changes in Dahlia tuberous roots over the vegetation period (2). This non-destructive spectroscopic technique enabled them to map inulin, lignin, and suberin across different root zones and cultivation conditions, offering a detailed look into the Dahlia roots’ biochemical landscape (2).

Inulin is a carbohydrate used in food as a prebiotic and dietary fiber (2,3). It is widely found in fruits and vegetables such as bananas, asparagus, and artichokes (3). In their study, when mapping inulin, the researchers were able to observe that it is the most abundant component in Dahlia roots. It was distributed throughout all examined root zones, especially concentrated in the periderm, or outermost layer, during forced cultivation periods (2). Forced cultivation, a method where growth is stimulated by controlled conditions, was found to increase the plant's inulin content in its early stages, particularly in spring (2).

The season and root zone also played key roles in the chemical makeup of lignin and suberin. Lignin and suberin have critical functions in dahlias. They help form the root structure and protection. The researchers found that lignin, a complex organic polymer that reinforces cell walls, was most prevalent in late autumn, especially in the inner root areas (2). Meanwhile, suberin, which is a hydrophobic barrier compound in roots, became more concentrated from summer to fall (2).

Through the FT-IR maps generated of the Dahlia roots, the researchers demonstrated that forced cultivation resulted in a dramatic increase of inulin compared to unforced conditions (2). The researchers theorized that this phenomenon occurred because of accelerated vegetative development (2). Early planting, a form of forced cultivation, allowed the plant to initiate assimilation processes earlier, resulting in higher inulin consumption throughout the season (2). This shift in inulin distribution has practical applications, as a higher concentration of inulin during spring and fall could be advantageous for industries seeking to maximize the nutritional or pharmaceutical value of Dahlia-derived products (2).

As a result, the main point from the study is that farmers and planters could be strategic in how they plant dahlias to achieve the desired outcome. Understanding how inulin, lignin, and suberin concentrations change under different cultivation methods and throughout various growth stages could guide agricultural practices that enhance both the economic value and sustainability of Dahlia crops (2). The authors propose that controlled cultivation techniques like forcing may not only influence plant yield but could also enable specific biochemical profiles in Dahlia roots to meet industrial demands (2).

As this study demonstrates, FT-IR imaging is a versatile and useful technique. Because of its ability to provide detailed biochemical insights, FT-IR imaging is a technique that can be used in a wide variety of industries, such as food analysis and pharmaceutical analysis.

References

1. Boeckmann, C. Planting, Growing, and Caring for Dahlias. The Farmer’s Almanac. Available at: https://www.almanac.com/plant/dahlias (accessed 2024-10-29).
2. Moldovan, I.; Cotoz, A.-P.; Rozsa, S.; et al. The Influence of Technological Factors on the Structure and Chemical Composition of Tuberous Dahlia Roots Determined Using Vibrational Spectroscopy. Plants 2024, 13 (14), 1955. DOI: 10.3390/plants13141955
3. WebMD, Inulin – Uses, Side Effects, and More. WebMD. Available at: https://www.webmd.com/vitamins/ai/ingredientmono-1048/inulin (accessed 2024-10-30).