Login


Plants force fungal partners to behave fairly

Plants react intelligently to their environment: If they can choose between more cooperative and less cooperative fungal partners, they supply the latter with fewer nutrients and thus force them to cooperate more. Based on these findings, scientists believe that plants could also be used to test market and behavioral theories.

Do plants operate according to economic criteria? They do, when they are mutualized with fungal partners that demonstrate differing degrees of cooperation. “Carbs for phosphates”, that’s the deal between plants and mycorrhizal fungi, which can only feed themselves together with a partner: The plant supplies the fungus with carbohydrates and is ‘paid back’ in phosphates. Additional phosphates are extremely attractive for the plant, as they allow it to grow better.

Good partners force worse partners to improve their performance
It really gets interesting when plants are mutualized with fungal partners of varying degrees of cooperativeness: a ‘meaner’ one, which supplies fewer phosphates per unit of carbohydrate provided, and a ‘more generous’ one, which ‘pays’ more phosphates for its nutrients. “In a case like this, the plant can deliberately decide to provide the meaner partner with fewer carbohydrates.” That’s how ecologists Pascal Niklaus and Bernhard Schmid from the University of Zurich (Switzerland) sum up the results of their new study.

As if that were not enough, the plant can practically ‘starve’ the less cooperative fungal partner by supplying it with fewer nutrients, thus forcing it to supply more of the sought-after phosphates. In this way the partner is encouraged to give back around the same amount as the more generous fungus. Andres Wiemken from the University of Basel explains this phenomenon as follows: “The plant exploits the competitive situation of the two fungi in a targeted manner, triggering what is essentially a market-based process determined by cost and performance”.

Based on this completely new insight into the behavior and decision-making ability of plants, the researchers believe that plants would be suitable for testing general market-based theories. “Because plants make their decisions based on physiological processes and are not distracted from the best course of action by subjective thought, they could even be better models than animals and people”, says Bernhard Schmid from the University of Zurich.

Better productivity thanks to mycorrhizal fungi
The basic research, funded by Syngenta within the framework of the “Plant Decision Making” Project at the Zurich-Basel Plant Science Center also provides practical findings for the agriculture sector. “Mycorrhizal fungi increase the sustainability and productivity of agricultural eco-systems”, explains Bernhard Schmid. For this reason, it is essential to maintain as much diversity within mycorrhizal fungi as possible in the agriculture sector going forward.

Age-old mutualism of plants and mycorrhizal fungi
Mycorrhizal fungi can survive only in the presence of a plant partner, as they are not able to feed themselves. The fungus uses its hyphae to penetrate the plant’s root system, where the plant supplies it with carbohydrates. The plant also benefits from this arrangement, as the fungus provides the plant with phosphates and other nutrients – with varying degrees of generosity. These natural fertilizers are decisive for plant growth, so mutualism with the mychorrhizal fungus is beneficial even if the fungus does not always cooperate fully.

Plant and mychorrhizal fungus mutualism has existed globally for more than 400 million years. Plant-fungus systems like these will play a significant role in more sustainable agriculture in the future.

Read the paper in Ecology Letters: Options of partners improve carbon for phosphorus trade in the arbuscular mycorrhizal mutualism.

Article source: University of Zurich

Image credit: UZH

News

More warm-dwelling animals and plants as a result of climate change

Since 1980, populations of warm-dwelling species in Germany have increased. The trend is particularly strong among warm-dwelling terrestrial species, as shown by the most comprehensive study across ecosystems in this regard to date. The most obvious increases occurred among warm-dwelling birds, butterflies, beetles, soil organisms and lichens according to the study published recently in the scientific journal “Nature Ecology & Evolution” led by Senckenberg scientists. Thus, it appears possible that rising temperatures due to the climate change have had a widespread impact on the population trends of animals in the past 30 years.


Winners and losers: climate change will shift vegetation

Projected global warming will likely decrease the extent of temperate drylands by a third over the remainder of the 21st century coupled with an increase in dry deep soil conditions during agricultural growing season. These results have been presented in Nature Communications by an international collaboration led by the US Geological Survey and members from seven countries, including Scott Wilson at the Climate Impacts Research Centre (CIRC) at Umeå University in Sweden.


New life for 19th-century plants

Humans have long had a knack for concentrating heavy metals that would otherwise remain at low concentrations within the environment. These human-produced pollutants can be found going back as far as one million years ago with fires in caves during the Paleolithic Era, to industrial development in the 19th century, to increased concentrations of contaminants like cadmium and lead in the 20th century.