Biological complexity: how plants roots find potassium (Introduction)

by David Turell , Tuesday, March 23, 2021, 19:38 (1122 days ago) @ David Turell

Special cell reactions do it:

https://www.sciencedaily.com/releases/2021/03/210323131227.htm

"Even when there was no potassium deficiency, the research team made a very surprising discovery: the concentration of this nutrient in the cytoplasm of the cells increased with each cell layer within the root, from the outside to the inside.

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"The team of researchers subsequently examined how roots react to potassium deficiency. In doing so, they demonstrated for the first time that if plants are subjected to potassium deficiency, the concentration of potassium is reduced only within certain cells in the root tip. These "postmeristematic cells" directly above the viable stem cells in the root tip react extremely rapidly to potassium deficiency; the concentration of potassium inside the cell (in the cytoplasm) decreases within seconds. It had not previously been known that a certain group of cells located centrally inside the root tip reacts to a potassium deficiency in its surroundings. The researchers named this group of cells "potassium-sensitive niche."

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"Simultaneously with the decrease in the potassium concentration in the potassium-sensitive niche, calcium signals occur in these cells and spread out in the root. As a messenger substance, calcium controls many processes in living organisms -- just as it does here: the calcium signals start off a complex molecular signalling cascade. This chain of signals, which the researchers were the first to define in detail, ultimately causes not only an increased formation of potassium transport proteins, but also brings about changes in tissue differentiation in the root. This facilitates a more efficient absorption of potassium ions and maintains its distribution in the plant. "For the first time," says Kudla, "using imaging methods, we have visualized the path of potassium in a living organism.'"

Comment: Again we see a complex mechanism that protects the plants ability to find a necessary nutrient. More design evidence.