Toxic invasive plant has twice as many genes as expected

For the first time, scientists have studied the genome of giant hogweed, an invasive and toxic plant whose juice causes skin burns. They found that its genome contains almost twice as many genes as most other plants. The study is published in The plant journal.

The research results open the door to practical applications in medicine and pharmacology, thanks to the unique bioactive molecules of giant hogweed, which can be used to create new drugs.

Sosnowsky hogweed (Heracleum sosnowskyi) is an invasive plant that has spread far beyond its natural habitat in the North Caucasus, posing a major threat to ecosystems and human health. After World War II, the plant was considered a promising fodder crop and was widely cultivated in northwestern European Russia.

From there, it began to spread, quickly invading larger areas and reducing biodiversity by driving out other plant species. In addition, its juice contains natural toxins that make the human body, mainly the skin and mucous membranes, very sensitive to ultraviolet rays and can cause burns and skin irritation upon physical contact.

Skoltech researchers and colleagues from the AA Kharkevich Institute for Information Transmission Problems of the Russian Academy of Sciences studied the complete genome of Sosnowsky hogweed and assembled it down to the level of chromosomes.

Using a DNA sequencer, the team obtained data on the plant’s genome and marked individual genes which, unexpectedly, turned out to be too numerous: 55,000 compared to 25,000 to 35,000 in most other plants. After proposing and testing several possible hypotheses, the researchers discovered that numerous gene duplications (copies) are responsible for this phenomenon.

“This is rather unusual, because plants usually have duplications across their entire genome and not just in its individual parts. Many gene families with a large increase in the number of genes in hogweed appear as the result of the synthesis of secondary metabolites, including linear furanocoumarins (psoralen and its derivatives), which make giant hogweed very dangerous,” explains Maria Logacheva, assistant professor at the Bio Center and member of the project team.

The researchers extensively analyzed genes that may be involved in the synthesis of toxins that cause daylight skin burns and experimentally determined the function of one of the genes that converts marmesin into psoralen.

The research results could be useful to medicine and pharmacology. Understanding the specific features of the hogweed genome will help identify and study its unique bioactive molecules, which could be used to create new drugs and therapeutic approaches for skin conditions. They can also help researchers develop biological control and monitoring methods for this pest plant.

“We plan to continue our research on the genome of giant hogweed and study the genetic diversity of this species in its native habitat and in “invaded” areas. We collect and analyze samples from across Russia, from Kaliningrad to the Far East, to understand the patterns and strategies of hogweed propagation, as well as learn more about the relationships between hogweed and related species, such as giant hogweed, which are spreading like wildfire in Western Europe,” concludes Logacheva.