In young roots, water enters directly into the xylem. In older roots, it may have to pass first through a band of phloem and cambium. It does so by traveling through horizontally-elongated cells, the xylem rays. Mineral Uptake One might have expected that minerals would enter the root dissolved in water. Anything that interferes with the metabolism of root cells interferes with mineral absorption.
Plants absorb their nutrients in inorganic form.
Organic matter does play an important role in making good soil texture, but only to the extent that it can yield inorganic ions can it meet the nutritional needs of the plant. Once within the epidermis, inorganic ions pass inward from cell to cell, probably through plasmodesmata . The final step from the cytoplasm of the pericycle cells to the xylem is probably accomplished once again by active transport. This sheath reduces water loss but is as impervious to oxygen and carbon dioxide as it is to water. However, the cork is perforated by nonsuberized pores called lenticels .