Research reveals that a multitude of plants, fungi, protists, bacteria, and viruses possess toxin delivery mechanisms.

These toxin delivery systems are completely similar and often rival the complexity of the venom delivery systems found in animals such as venom snakes, scorpions, and spiders.

Four representative plant species introducing the poison delivery system: (a) Many ant plants share ants that provide homes and food. (b) Horstria, a parasitic plant that attacks other plants. (c) Stingy trichomes of stinging plants. (d) Raffide penetrates the oral membrane of an animal browsing a plant. Image credit: Hayes et al. , doi: 10.3390/toxin 17030099.

Toxologists and other biologists have studied toxic organisms and their secretions for centuries.

Their interest is largely due to the frequently and severe consequences of human exposure.

Humans also take advantage of the potential of toxins to explore the treatment of human illnesses and illnesses.

In doing so, scientists have leveraged countless natural experiments involving interactions between toxins and target cells and tissues.

The classification of biological toxins, in particular the distinction between venom and venom, is characterized by a colorful and sometimes controversial history.

Nevertheless, with the views of consensus and the introduction of the third phase, toxic biological secretions can be divided into three groups based on their mode of delivery to other organisms.

These include poisons that are transmitted passively without a delivery mechanism (intake, inhalation, or absorption of the entire surface). Toxicity was fed to the body surface without any associated wounds (e.g., spitting, spraying, or smearing). Poison (e.g., sting, biting) carried to internal tissues through the formation of wounds.

The organisms that possess these toxins are called toxic, toxins, and/or toxic, respectively.

These distinctions provide a meaningful framework for studying the evolution of these toxins, including biochemical structures. Related structures for synthesis, storage and application. And their functional role.

Discourses on poison and poisonous animals focus exclusively on animals.

The use of venom has evolved independently in at least 104 strains within at least eight animal phylums, which emphasizes the pronounced adaptability of the trait.

But do poison distribution systems exist in other entities?

“Our findings show that we rely on poisons to solve problems such as predation, defense, and competition.

“The venomous animals have long been trying to understand the fatal secretions and the properties associated with their use, but have long fascinated biologists who have also contributed to many life-saving treatments.”

“To date, our understanding of venoms, poison delivery systems, and poisonous organisms is entirely based on animals. This represents only a small fraction of organisms that can search for meaningful tools and treatments.”

According to the study, plants inject toxins into animals through spines, thorns and stinging hairs, some of which exist with stinging ants by providing living space and food in exchange for protection.

Even bacteria and viruses have evolved mechanisms such as secretory and contractile injection systems to introduce toxins to the target through host cells and wounds.

“I have a long history of studying venom in rattlesnakes, and I began exploring the broader definition of venom over a decade ago, teaching special courses on the biology of venom,” Professor Hayes said.

“My team and I were working on a paper to define what Venom really is, so we came across non-animal examples and decided to dig deeper to identify many of the possible overlooked examples.”

This research paves the way for new discoveries, and the authors hope that experts and scientists will encourage collaboration across disciplines and explore further how Venom has evolved across diverse organisms.

“We only hurt the surface in understanding evolutionary pathways of venom dissemination, including gene duplication, co-configuration of existing genes, and natural selection,” concluded Professor Hayes.

study Published in the journal toxin.

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William K. Hayes et al. 2025. After all, it’s a small world. It is a prominent yet overlooked diversity of poisonous organisms with candidates for plants, fungi, protists, bacteria and viruses. toxin 17(3):99; doi:10.3390/toxin 17030099

Source: www.sci.news

Scientists unravel the composition of the unique toxin found in black widow spider venom

Black widow spider venom contains a cocktail of seven specific latrotoxins, but only one, alpha-latrotoxin, targets vertebrates, including humans. chemist of University of Munster They have now deciphered the structure of alpha-latrotoxin before and after membrane insertion at near atomic resolution.

Cryo-EM structures of α-latrotoxin in two different tetrameric states. Image credit: Klink others., doi: 10.1038/s41467-024-52635-5.

Latrotoxin is the main toxic component of the venom of black widow spiders (genus). latrodectus).

The toxins include five insecticidal toxins known as α-latrotoxin, α-, β-, γ-, δ-, and ε-latroinsect toxins, which are unique to vertebrates, and one toxin that is unique to crustaceans.

“Alpha-latrotoxin interferes with nervous system signal transmission,” said researcher Björn Klinck and colleagues at the University of Münster.

“As soon as alpha-latrotoxin binds to specific receptors at the synapse (contacts between nerve cells or between nerve cells and muscles), calcium ions flow uncontrollably into the presynaptic membrane of the signal-transmitting cell.”

“This triggers the release of neurotransmitters, which causes strong muscle contractions and spasms.”

“Although this process seems simple at first glance, there are very complex mechanisms behind it.”

To better understand the mechanism of calcium influx into the presynaptic membrane, the authors used high-performance cryo-electron microscopy (cryo-EM) and molecular dynamics (MD) computer simulations.

They showed that alpha-latrotoxin undergoes significant changes when it binds to the receptor.

Some of the toxic molecules form stalks and penetrate the cell membrane like a syringe.

As a special feature, this stalk forms small pores in the membrane, which act as calcium channels.

MD simulations revealed that calcium ions can enter the cells through a selection gate on the side directly above the pore.

“This toxin mimics the function of calcium channels in the presynaptic membrane in a very complex way,” said Christos Gatsogiannis, a researcher at the University of Münster.

“Therefore, it is different in every way from any toxin known to date.”

“The new discovery opens up a wide range of potential applications.”

“Latrotoxin has considerable biotechnological potential, including the development of improved antidotes, treatments for paralysis, and new biopesticides.”

of study Published in a magazine nature communications.

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Clink BU others. 2024. Structural basis of α-latrotoxin transition to cation-selective pores. Nat Commune 15, 8551; doi: 10.1038/s41467-024-52635-5

Source: www.sci.news