Question

Minerals are present in the soil in sufficient amounts. Do plants need to adjust the types of solutes that reach the xylem? Which molecules help to adjust this? How do plants regulate the type and quantity of solutes that reach xylem?

Answer 1

Soil contains a sufficient amount of minerals in it but solutes received by the xylem need to be adjusted by the plant. Soil contains minerals in the form of ions, some minerals are absorbed passively by the root hairs from the soil and some actively, this active transport of mineral ions is controlled by the special membrane proteins in root hairs. The transport proteins are also present in endodermal proteins. Mineral ions are selected by these transport proteins for the uptake, which means these transport proteins select the mineral ions for uptake, not all ions are allowed to enter. These transport proteins act as gatekeepers where they permit the quantity and type of solute to enter the xylem and just one-way ion transport is allowed by the epidermis of suberin layer.