Quick responders
Plants may be fixed in the ground. But they are quick responders. This is shown once again in recent research. Wherein a team of international researchers tells us that plants and algae respond within 30 seconds to the plant hormone auxin.
The hormone auxin is about involved in almost everything in relation to plant development. Not surprising we know a lot about how this hormone does its job. But not everything. Like we know that there are quick and slow reactions in response to auxin. About the slow reactions we know that this occurs via gene regulation. But about the quick reactions to auxin less is known.
This researchers decided to decipher in more detail. They did not only study this in the model plant tale cress, but also in two moss species and two species of algae. The first thing they did was confirm that the chosen species have a fast auxin response. In order to be able to compare the results the researchers studied this at cellular level. In specific they looked at the polarisation of the cell membrane and at movement within the cell. For both studied processes the researchers observed a reaction within 5 minutes.
This quick response ability is extremely ancient
The next question was of course how these species are reacting that quickly. To find out they analysed the labelling of proteins with a phosphate group. A phosphate label can influence the function of a protein, like activating it. It turned out that already 30 seconds (the shortest analysed time) after auxin exposure lots of proteins were decorated with a fresh phosphate tag.
With help of identified labelled proteins the researchers found out that in each species a small group of proteins was behind the phosphate labelling of the other proteins. When the researchers compared these label giving proteins one protein family was turning up every single time. The RAF-kinases. Even in algae were these proteins labelling other proteins in response to auxin. Because algae and land plants like mosses and tale cress are on an evolutional level very distant, it means that this type of quick response ability is extremely ancient.
Thus plants are reacting for a verry long time verry quickly to auxin. Only researchers did not really noticed this before. But now this is changed. And we can study the effect of the quick response to auxin. Like which reactions are so quickly initiated by the plant.
Literature
Kuhn et al., RAF-like protein kinases mediate a deeply conserved, rapid auxin response, Cell (2024), https://doi.org/10.1016/j.cell.2023.11.021
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