In C4 plants, sodium is a micro nutrient that aids in metabolism, specifically in regeneration of phosphoenolpyruvate and synthesis of chlorophyll. [C4 carbon fixation is one of three biochemical mechanisms, along with C3 and CAM photosynthesis, used in carbon fixation. It is named for the 4-carbon molecule present in the first product of carbon fixation in the small subset of plants known as C4 plants, in contrast to the 3-carbon molecule products in C3 plants.]As a theologian I strongly object to the wording in the green paragraph of an expert article on sodium - the writer uses active mode suggesting thereby that plants developed by themselves strategies for a given purpose.
In others, it substitutes for potassium in several roles, such as maintaining turgor pressure and aiding in the opening and closing of stomata.
Excess sodium in the soil limits the uptake of water due to decreased water potential, which may result in wilting; similar concentrations in the cytoplasm can lead to enzyme inhibition, which in turn causes necrosis and chlorosis.
To avoid these problems, plants developed mechanisms that limit sodium uptake by roots, store them in cell vacuoles, and control them over long distances; excess sodium may also be stored in old plant tissue, limiting the damage to new growth.
The writer of the sentences probably does not think that plants are highly intelligent beings and figured out solutions (or solvents) to the problem caused by excessive sodium in the environment! Rather, there is probably some kind of theory of evolution of plants in the writer's mind and some mechanism where the blind force of survival of the fittest is the genius we see at work in nature.
In this blog I only point at interesting things as a tour guide to the Gardens of God. I hope to inspire you - and me - to read much more about sodium that is made in massive stars in the Space and which is so important to living things, animals and plants, upon Earth.
The Internet and traditional libraries have an overwhelming amount of information about what humanity has learned about the element Latins called natrium.