Fatty acids are important nutrients for plants, and they are typically absorbed by the root system through a process called uptake. The roots of plants have small outgrowths called root hairs that are responsible for absorbing nutrients, including fatty acids, from the soil. Root hairs are covered in a thin layer of mucilage, a gel-like substance that helps to trap soil particles and nutrients, including fatty acids.
When a root hair encounters a soil particle that contains fatty acids, the fatty acids are drawn into the root hair by a process called diffusion. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. In this case, the fatty acids in the soil have a higher concentration than the fatty acids inside the root hair, so they diffuse into the root hair.
Once inside the root hair, the fatty acids are transported across the plasma membrane of the root hair cell by specific transporters. These transporters are responsible for pumping the fatty acids across the membrane and into the cell where they can be used by the plant.
The fatty acids are then transported to the plant's other organs and cells, where they are used for various purposes such as energy storage, as building blocks for the membranes, in biosynthesis of different compounds and even as signaling molecules. It's also worth mentioning that some plants can also obtain fatty acids from microorganisms. This process called Rhizophagy, where the plant can host specific microbes that are capable of producing or hydrolyzing fatty acids and then the plant will use these compounds.
References:
- "Fatty acid uptake by plant roots" by W.P. Quick, Plant and Soil, vol. 199, pp. 149-161, 1998.
- "Transport of fatty acids across plant cell membranes" by J.L. Harwood, Journal of Experimental Botany, vol. 45, pp. 1065- 1075, 1994.
- "Root hair uptake of lipids in plants" by K. Vermaas and A.A. Hoffland, Plant and Soil, vol. 314, pp. 195-205, 2009
- "Rhizosphere-microbe-plant interactions: complementary insights from the Rhizosphere Carbon Flow and Microbe-Root Interaction networks" by K.S. Pregitzer, Plant and Soil, vol. 391, pp. 1-16, 2015.
- "The Role of Microbes in the Rhizosphere of Plants: Implications for Phytoremediation" by S.G. Petrovic, R.D. Finkelstein and J.M. Suflita, Biotechnology Advances, vol. 29, pp. 185-197, 2011.