Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Farming and chemical warfare: a day in the life of an ant?

17.11.2008
One of the most important developments in human civilisation was the practice of sustainable agriculture. But we were not the first - ants have been doing it for over 50 million years.

Just as farming helped humans become a dominant species, it has also helped leaf-cutter ants become dominant herbivores, and one of the most successful social insects in nature. According to an article in the November issue of Microbiology Today, leaf-cutter ants have developed a system to try and keep their gardens pest-free; an impressive feat which has evaded even human agriculturalists.

Leaf-cutter ants put their freshly-cut leaves in gardens where they grow a special fungus that they eat. New material is continuously incorporated into the gardens to grow the fungus and old material is removed by the ants and placed in special refuse dumps away from the colony. The ants have also adopted the practice of weeding. When a microbial pest is detected by worker ants, there is an immediate flurry of activity as ants begin to comb through the garden. When they find the pathogenic 'weeds', the ants pull them out and discard them into their refuse dumps.

"Since the ant gardens are maintained in soil chambers, they are routinely exposed to a number of potential pathogens that could infect and overtake a garden. In fact, many of the ant colonies do become overgrown by fungal pathogens, often killing the colony," said Professor Cameron Currie from the University of Wisconsin-Madison, USA. "Scientists have shown that a specialized microfungal pathogen attacks the gardens of the fungus-growing ants. These fungi directly attack and kill the crop fungus, and can overrun the garden in a similar fashion to the way weeds and pests can ruin human gardens."

A curious observation was that some worker ants had a white wax-like substance across their bodies. When they looked at it under a microscope scientists discovered that this covering was not a wax, but a bacterium! These bacteria are part of the group actinobacteria, which produce over 80% of the antibiotics used by humans. The bacteria produce antifungal compounds that stop the microfungal pathogen from attacking the garden. This discovery was the first clearly demonstrated example of an animal, other than humans, that uses bacteria to produce antibiotics to deal with pathogens.

"Research in our laboratory has revealed a number of interesting properties between the bacteria and the pathogenic fungus. The bacteria appear to be specially suited to inhibiting the pathogenic fungi that infect the ants' fungus garden," said Professor Currie.

The interaction between the ants and their fungus crop, and the ants and the bacteria is known as a mutualistic relationship. In general a mutualism is established when both members of the interaction benefit from the relationship. In the ant-fungus mutualism, the ants get food from the fungus. This mutualism is so tight that if the fungus is lost, the entire colony may die. In return, the fungus receives a continuous supply of growing material, protection from the environment, and protection from disease-causing pests.

So what do the bacteria get out of producing pesticides for the ants? "For starters, they get food. Many species of fungus-growing ants have evolved special crypts on their bodies where the bacteria live and grow. Scientists believe that the ants feed the bacteria through glands connected to these crypts," said Dr Garret Suen, a post-doctoral fellow in Professor Currie's lab. "Also, the bacteria get a protected environment in which to grow, away from the intense competition they would face if they lived in other environments such as the soil."

"Interestingly, the tight association between ant, bacteria and pathogen will sometimes result in the pathogen winning. This interplay has been described as a chemical 'arms race' between the bacteria and fungus, with one side beating the other as new compounds are evolved," said Professor Currie. "At the moment, we are beginning to understand the chemical warfare at the genetic level, and it is likely that these types of interactions are more prevalent in nature than previously thought."

So how exactly does an ant go about forming partnerships with a fungus and a bacterium? No one really knows. With new advances in molecular and genetic technologies, such as whole-genome sequencing, Professor Currie and Dr Suen hope to discover how these associations were established, and to understand how these interactions resulted in the remarkable fungus-growing ability of the ants.

Lucy Goodchild | alfa
Further information:
http://www.sgm.ac.uk

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>