Potassium is one of the nutrients that plants need in large quantities. However, the amount of potassium in the soil can vary greatly: potassium-poor soils can contain up to a thousand times less of this nutrient than potassium-rich soils. To be able to react flexibly to these differences, plants have developed mechanisms with which they adapt their potassium uptake to the respective soil condition.

Like the cells of the human body, plant cells also work with an operating potassium concentration of around 100 millimolar. If the roots find a potassium source with a significantly lower concentration or only traces of it, they can only absorb the potassium into their cells by expending energy. This is achieved by the interaction between the potassium ion channel AKT1 and the potassium transporter HAK5.

Research is Relevant for Plant Breeding

‘Although HAK5 has been known since the late 1990s, its transport mechanism has so far remained largely unknown,’ says Professor Rainer Hedrich from Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany. A team led by the Würzburg biophysicist now wanted to elucidate this mechanism: ‘Knowledge about this is important when it comes to breeding crops that also produce yields on non-fertilised or only lightly fertilised fields, i.e. that can manage with less fertiliser.’

In their experiments, the Würzburg research group led by first authors Tobias Maierhofer and Sönke Scherzer benefited from their extensive experience with the potassium channel AKT1. The group now describes their results in detail in the journal Nature Communications.