Plants Save Energy when Absorbing Potassium
en-GBde-DEes-ESfr-FR

Plants Save Energy when Absorbing Potassium


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.

Establishing a pH Gradient Costs Energy

For the AKT1 channel to transport potassium into the cells, higher soil potassium concentrations are required. The normal electric field of the cell membrane is sufficient as an energy source. The HAK5 transporter, on the other hand, already works at low soil potassium levels. In addition to the electric field, it needs the energy of the pH gradient. The plant must build up this gradient across the cell membranes, and this costs energy.

Further experiments showed that the potassium transporter HAK5 and the potassium channel AKT1 co-operate in an energy-saving manner when the potassium concentration in the soil fluctuates.

Transporter Must Have a Potassium Sensor

At high concentrations, the energy-guzzling transporter HAK5 is switched off. This means that the transporter must have a potassium sensor. In their search for the sensor, the Frankfurt structural biologist Inga Hänelt and her Würzburg colleague Thomas Müller made progress: they found a mutant of the transporter in which the affinity for potassium is 100 times lower.

‘Now it is important to explore in more detail the molecular reactions that trigger the mutation,’ says Rainer Hedrich, describing the next research goals. He also wants to find out how potassium transport into the root cell is mechanically and energetically coupled to proton transport.
Arabidopsis HAK5 under low K+ availability operates as PMF powered high-affinity K+. Tobias Maierhofer, Sönke Scherzer, Armando Carpaneto, Thomas D. Müller, Jose M. Pardo, Inga Hänelt, Dietmar Geiger & Rainer Hedrich, Nature Communications, 3 October 2024, Open Access: https://www.nature.com/articles/s41467-024-52963-6
Fichiers joints
  • Plants have two separate potassium uptake systems, the transporter HAK5 and the channel AKT1. Depending on the potassium concentration in the soil, one or the other system is responsible for the uptake of potassium into the roots. This ensures a constant supply of potassium even when potassium availability varies. (Image: Tobias Maierhofer / University of Würzburg)
Regions: Europe, Germany
Keywords: Science, Agriculture & fishing, Life Sciences

Disclaimer: AlphaGalileo is not responsible for the accuracy of news releases posted to AlphaGalileo by contributing institutions or for the use of any information through the AlphaGalileo system.

Témoignages

We have used AlphaGalileo since its foundation but frankly we need it more than ever now to ensure our research news is heard across Europe, Asia and North America. As one of the UK’s leading research universities we want to continue to work with other outstanding researchers in Europe. AlphaGalileo helps us to continue to bring our research story to them and the rest of the world.
Peter Dunn, Director of Press and Media Relations at the University of Warwick
AlphaGalileo has helped us more than double our reach at SciDev.Net. The service has enabled our journalists around the world to reach the mainstream media with articles about the impact of science on people in low- and middle-income countries, leading to big increases in the number of SciDev.Net articles that have been republished.
Ben Deighton, SciDevNet
AlphaGalileo is a great source of global research news. I use it regularly.
Robert Lee Hotz, LA Times

Nous travaillons en étroite collaboration avec...


  • BBC
  • The Times
  • National Geographic
  • The University of Edinburgh
  • University of Cambridge
  • iesResearch
Copyright 2024 by DNN Corp Terms Of Use Privacy Statement