Mutualistic Relationship Between Trees and Ants | Ask A Biologist
An enzyme in the nectar of acacia trees makes ants chemically dependent on their sugar. The report illustrates how evolution keeps cooperative relationships among some Quiz: How much do you depend on palm oil?. Researchers at the Max Planck Institute for Chemical Ecology in Jena, Germany, have now found that ants also keep harmful leaf pathogens in check. In return for room and board, mutualistic Pseudomyrmex ferrugineus ants become bodyguards, protecting their host against herbivores. These results generate additional questions about the selective forces We sampled all 10 species of obligate acacia ants in the P. Most phylogenetic analyses, including divergence dating, were we generated these trees by pruning taxa from the trees containing all taxa using the R package APE .
In other words, these symbioses, in which both partners benefit by cooperating with each other, are mutualistic. Sometimes, however, the relationship is non-reciprocal, and the ants parasitize their hosts, without conferring any advantage on the plant.
Reconstructing the phylogeny of symbioses In order to elucidate the evolutionary history of the symbioses between these ant species and their hosts, the researchers used DNA sequence data for up to 10 nuclear genes to construct phylogenetic trees for both ants and plants. By then applying the molecular clock method, they were able to determine the temporal sequence of divergence of the lineages leading to the species involved in modern-day symbioses.
Comparisons of the trees revealed when each ant species could have formed a symbiotic relationship with its plant hosts.
- Trees Get By with Ant Aides
- Ants protect acacia plants against pathogens
The results clearly demonstrate that such partnerships are not static. The more remote the date of establishment of the initial symbiosis, the greater is the chance that the original symbiotic partner will be evicted. Its niche then becomes available for a different species — for once a plant is forming domatia, there is competition for these living quarters from other plant-nesting ants.
Indeed, purely parasitic ant species are always found to be phylogenetically younger than the domatia in which they live which developed in the context of a true symbiosis. Protection Against Insects The ants do not harm the acacia tree, but there are several insects which might harm wither the leaves, rot the flowers, etc.
The evolutionary history of symbioses between tropical ants and their plant hosts
The ants ward off all other insects which try to occupy the acacia, thus protecting the tree from any damage. Defense Against Herbivores Apart from the insects, the acacia also faces a threat from herbivores. The ants protect the tree from herbivores too.
When the herbivores try to eat the leaves of the acacia, they cause the branches of the tree to move, this acts as a signal to the ants living in the domatia. The ants quickly reach the herbivore who is trying consume the leaves, and start stinging it. After some resistance, the herbivore gives up, and leaves the tree alone.
In addition to this, the ants also eliminate any plants that try to grow on, or near the acacia, hence the acacia does not need to compete for resources. Special Features of the Acacia-Ant Relationship The relationship between the acacia and the ant is characterized by the interesting features mentioned below: Possessiveness of the Ants The acacia and the ants share such a close bond that, as time goes by, the ants become very possessive about the tree on which they dwell.
They also attack other species of ants which try to occupy the tree. Distinct groups of ants usually compete for the acacia. Manipulation by the Acacia The ants attack all the insects which try to feed on the acacia, but it does not harm the pollinators.
Relationship Between Acacia Tree and Ants
One species of Acacia, namely the whistling-thorn A. These trees seldom experience elephant herbivory. If elephants attempt to consume branches of the whistling-thorn, ants swarm the trunk of the elephant biting the sensitive internal areas.
This defense is extremely effective. In return, the trees pay back their body-guards with housing in the form of swollen thorns called domatia. Many different species of plants not just Acacia provide domatia for ants, mites, and other arthropods things with jointed legs such as insects and spiders which provide the plant with some service in return. For a video of what the inside of a typical domatia looks like not A.
Ants and Trees: A Lifelong Relationship - American Forests
On top of domatia, A. This nectar provides some species of guard-ants with all the food they need. The mutualistic ant Crematogaster nigiceps feeding on a extrafloral nectaries on Acacia drepanolobium.The Double-Crossing Ants to Whom Friendship Means Nothing - Deep Look
Photo courtesy of Todd Palmer.