May 03, 2021 12:00:00

It turns out that fungi that coexist with plants collect and use bacteria in the surrounding soil

A research team at the Boyce Thompson Institute at Cornell University reported that they have discovered bacteria that help fungi and plants absorb nutrients in the soil. The availability of this bacterium is expected to improve crop yields and reduce fertilizer reliance.

Conserved and reproducible bacterial communities associate with extraradical hyphae of arbuscular mycorrhizal fungi | The ISME Journal
https://www.nature.com/articles/s41396-021-00920-2

Soil bacteria could improve crop yields, via fungi | Cornell Chronicle
https://news.cornell.edu/stories/2021/04/soil-bacteria-could-improve-crop-yields-fungi

It is already known that bacteria in the soil have a symbiotic relationship with plants. For example, fungi called rhizobia reduce nitrogen in the atmosphere to make it easier for plants to absorb, and in return they have a symbiotic relationship with receiving photosynthetic products from plants.

In addition, approximately 70 percent of the land plants, the root arbuscular mycorrhizal have a symbiosis of bacteria called fungi (AM fungi), has been found to be exchanged with nitrogen and phosphorus fatty acids AM bacteria to produce .. However, since AM bacteria do not have the enzymes required to obtain nitrogen and phosphorus from complex organic molecules, the mechanism of how nitrogen and phosphorus are obtained was unclear.

A research team led by Professor Maria Harrison of the Boyce Thompson Institute is investigating whether there are other AM bacteria that help plants absorb nutrients, two types of AM, 'Glomus versiforme' and 'Rhizophagus irregularis'. The fungus was prepared and coexisted with Brachypodium distachus, which is a model plant of monocotyledonous plants, in three different types of soil and observed. The research team then allowed the bacteria to grow with Brachypodium distachus for up to 65 days and then identified the bacteria attached to the hyphae from the gene sequence.

As a result, it was found that the composition of bacteria found in the soil around Brachypodium distachus was surprisingly consistent. In addition, the bacterial composition was significantly different in places far away from Brachypodium distachus. In other words, certain bacteria were attracted to AM bacteria that coexist with plants.

The research team pointed out that AM bacteria may secrete molecules to attract these bacteria, 'It is possible that the attracted bacteria also have some effect on AM bacteria.' Stated. The research team also predicts that 'some of the bacteria found release phosphorus ions from organic matter, which may be the cornerstone of the AM bacterium's phosphate acquisition process.'

In addition, the bacterial group found in the soil around Brachypodium distachus also contained myxobacteria that eat other bacteria. It has also been pointed out that the mineral content in the soil may increase because myxobacteria have eaten some of the bacteria. 'By identifying bacterial groups around AM bacteria, the research team will be able to understand the interaction between AM bacteria and bacteria and devise important strategies to support the ecological enhancement of agricultural systems. I will. '