Abstract
Imagine a crime scene with no clues—no cameras, no witnesses—just a tiny hair or a drop of blood. Scientists can still solve the mystery using DNA, a special code inside every living thing. DNA is like a fingerprint—it is different for every person, and that is why detectives use it to catch criminals. Did you know that plants have their own unique DNA fingerprints too? This article explores how two DNA-based techniques can help identify plants and tell them apart. DNA barcoding helps determine a plant’s species by analyzing a small, specific region of its DNA. Genetic fingerprinting examines multiple DNA regions to reveal differences that make individual plants or varieties unique. This article highlights how plant fingerprinting techniques support agriculture, conservation, and biodiversity by helping improve crops through the identification of beneficial traits, preventing misidentification, and protecting rare or endangered species through genetic monitoring.
Every Plant Has A Secret Code
Just like people, every plant has DNA—a long, invisible instruction book made of billions of tiny chemical building blocks arranged in a unique order. We will call these DNA building blocks “letters” because they are often represented by the letters A, C, T, and G. DNA tells the plant how to grow, determines what it looks like, and generally allows it to survive. Even though we cannot see it, DNA works behind the scenes in every leaf, root, and flower. Surprisingly, two plants that look different, like a red tomato and a yellow one, can have DNA that is more than 99% the same. It is the tiny 1% of differences that makes each plant unique.
DNA Barcoding: What Plant Are You Looking At?
Imagine you are hiking and find a mysterious leaf on the ground. There are no flowers, no fruit—nothing to help you figure out what plant it came from. This is where DNA barcoding could help.
DNA barcoding works a lot like scanning the barcode of a product at the store to find out exactly what it is. Scientists do something similar with plants—they read a short, specific part of the plant’s DNA that is different between species. Once they have that “barcode”, they compare it to a DNA database to find out what kind of plant it is (Figure 1). So barcoding is super helpful when you want to answer the question “What is this plant?” [1].
- Figure 1 - The image shows a person in two roles: on the left, a store worker scans a product’s barcode to find out what it is; on the right, a scientist analyses a DNA sequence to identify a species.
- Just as barcodes reveal a product’s identity, DNA barcodes help scientists determine what species a sample belongs to (Figure enhanced with AI tools).
Genetic Fingerprinting: What Makes A Plant One Of A Kind?
Sometimes knowing the species is not enough. What if you want to know which variety of tomato you are growing? Or whether two trees that look identical are actually the same? That is when scientists use a technique that is even more detailed: genetic fingerprinting [2]. A genetic fingerprint looks at many parts of a plant’s DNA, not just one small region like barcoding does. Fingerprinting reveals the tiny differences that make one variety of a plant different from another, or even what makes a single plant unique. While barcoding answers “What species is this?”, fingerprinting goes further and asks, “Which specific plant is this?”.
Small Changes That Matter
To build a genetic fingerprint, scientists look for tiny changes in the DNA code called single nucleotide polymorphisms (SNPs, pronounced “snips”). SNPs are small changes in just one letter of an organism’s DNA (Figure 2). You can think of SNPs like changing the word “CAT” to “BAT”. This is only a one-letter change, but it completely changes the word. That is how a single SNP can change something important in a plant—like how it tastes, how fast it grows, or how well it handles hot weather.
- Figure 2 - The DNA sequences of the red and yellow tomatoes are almost identical.
- The only difference is in one position highlighted in the blue box. This single-letter difference is called a SNP. Even though it is just one tiny change in the DNA code, scientists can use SNPs as a way to tell plants apart, study diversity, and connect DNA differences with traits such as fruit color (Figure enhanced with AI tools).
How Scientists Find Genetic Fingerprints
To find SNPs, scientists follow several important steps. First, they collect plant tissue (for example, from leaves) and they extract and purify the DNA from that tissue. The purified DNA is loaded into powerful machines that read it letter by letter (you can read more about DNA sequencing in this Frontiers for Young Minds article). Then, computer programs compare the DNA from one plant to another, lining up the sequences to spot the small changes. (You can read more about DNA sequence comparison in this Frontiers for Young Minds article). It is a bit like playing a giant game of “spot the difference”, but with genetic code. Once they have found enough of these differences, the scientists can create a genetic fingerprint for that plant, like giving it its own ID card.
Why Plant Fingerprints Matter
Genetic fingerprints are incredibly useful. In a recent study, we looked at more than 150 chestnut trees [3]. Many of them had the same name and looked almost exactly alike. But their DNA told a different story. Some trees had unique genetic fingerprints, showing they were not actually the same at all. These tiny differences in DNA can reveal how a plant handles drought, disease, or changes in temperature. They can show where a plant originally came from. And they can even help scientists understand how plants have changed over time.
Protecting Plants And The Planet
DNA fingerprinting is also important for protecting biodiversity (you can read more about biodiversity in this Frontiers for Young Minds article). Pollution, climate change, and habitat loss are putting many plants at risk. When plants lose their genetic differences, they become weaker and less able to survive. By studying plant DNA now, scientists can identify and preserve genetic diversity, helping protect important traits before they disappear through habitat loss or extinction.
Fingerprints can also help when people mix up plants—like calling two different plants the same name or giving one plant multiple names. With DNA, there is no confusion. Genetic fingerprinting helps scientists identify crop plants with useful traits, such as better growth or disease resistance. It also helps farmers avoid planting the wrong varieties and protects breeders by using DNA fingerprints to prove that new crops they develop are unique and original.
In summary, DNA fingerprinting helps scientists identify plants, understand how they are related, and discover useful traits such as disease and stress resistance. It also helps protect endangered species, preserve biodiversity, support farmers in using the right crops, and help breeders prove that the new crop varieties they create are truly their own. Even the smallest change in DNA can tell an important story about a plant’s past, present, and future.
Glossary
DNA: ↑ The molecule that carries the instructions for how every living thing grows and functions.
DNA Barcoding: ↑ A method of identifying species by analyzing a short, standardized region of their DNA.
Genetic Fingerprint: ↑ A unique pattern in DNA that helps identify a specific person, plant, or animal.
Single Nucleotide Polymorphism (SNP): ↑ A change in just one letter of the DNA sequence.
DNA Sequence: ↑ The exact order of the letters (A, T, C, G) in a strand of DNA.
Biodiversity: ↑ The variety of living things in nature, including small differences within species.
Acknowledgments
This work was supported by 2014IT06RDRP019: Italy—Rural Development Programme (Regional)—Campania PSR CAMPANIA 2014/2020, TIPOLOGIA DI INTERVENTO 16.1.2, within the project KasTrack—Tracciabilità delle cultivar di castagno mediante tecnologia KASP per il rilievo delle impronte genetiche (DICA PG/2024/0071218 - 08/02/2024, CUP B59H23000040006).
AI Tool Statement
The author(s) declared that Generative AI was used in the creation of this manuscript. The figures were first sketched on paper and later enhanced using AI tools for clarity and presentation.
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Conflict of Interest
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
References
[1] ↑ Hebert, P. D., Cywinska, A., Ball, S. L., and deWaard, J. R. 2003. Biological identifications through DNA barcodes. Proc. Biol. Sci. 270:313–21. doi: 10.1098/rspb.2002.2218
[2] ↑ Nybom, H., Weising, K., and Rotter, B. 2014. DNA fingerprinting in botany: past, present, future. Investig. Genet. 5:1. doi: 10.1186/2041-2223-5-1
[3] ↑ Fruggiero, I., Maisto, A., Passaro, S., Nunziata, A., and D’Agostino, N. 2025. KASTRACKdb - a database of chestnut DNA fingerprints for genetic diversity assessment, precise varietal identification, and traceability. Database. 2025:baaf056. doi: 10.1093/database/baaf056