Plant & zo
The science of plants and more
Flourishing with a little bacterial help
Bacteria and fungi in the soil unlock mineral sources of nitrogen, sulphate, and iron. Transforming these minerals into a form that plants can uptake. While these microorganisms are always useful, they are essential in arid soils that have accumulated huge mineral quantities. Such as the Atacama Desert. Here large groves of the Atacama Desert giant horsetail (Equisetum xylochaetum) grow in the valley streambeds. Researchers wondered if these large plants got some microbial help to flourish in such harsh environment.
They analysed the bacteria attached to the roots of the giant horsetail. Among the bacteria they found species that specialised in either fixing nitrogen, reducing sulphate or iron. Not only that, but the genes for proteins needed for these reactions were turned on. Suggesting that when the researchers took the sample, these bacteria were busy with fixing nitrogen, reducing sulphate or iron. The close contact of the bacteria with the horsetail roots means that the plants have direct access to these unlocked minerals. Directly benefitting their growth.
Disturbing and mining soils influences the types of bacteria present in those soils
In the past the large mineral quantities in the Atacama Desert were mined, disturbing the soil. The researchers compared the microbes attached to roots from past mining sites with those on roots of plants on less disturbed soils. On both sites the roots had lots of microbes attached. But not the same microbes. While the roots from less disturbed soils had lots of active beneficial bacteria, those of disturbed soils had not so much. Suggesting that disturbing and mining soils influences the types of bacteria present in those soils.
Harsh environments, like the Atacama Desert show us the importance of the interaction between microorganisms and plants. Microorganisms help plants flourish in this stressful environment. And as the researchers say, this is something to keep in mind if we want to protect these ecosystems.
Literature
Anchittha Satjarak, Linda E Graham, Marie T Trest, Joy Zedler, Jennifer J Knack, Patricia Arancibia-Avila, Nitrogen fixation and other biogeochemically important features of Atacama Desert giant horsetail plant microbiomes inferred from metagenomic contig analysis, Annals of Botany, 2022;, mcac060, https://doi.org/10.1093/aob/mcac060
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