Search results
Results from the WOW.Com Content Network
Active absorption refers to the absorption of water by roots with the help of adenosine triphosphate, generated by the root respiration: as the root cells actively take part in the process, it is called active absorption. According to Jenner, active absorption takes place in low transpiring and well-watered plants, and 4% of total water ...
Mucigel is a slimy substance that covers the root cap of the roots of plants. It is a highly hydrated polysaccharide, [1] most likely a pectin, which is secreted from the outermost (epidermal) cells of the rootcap. Mucigel is formed in the Golgi bodies of such cells, and is secreted through the process of exocytosis.
In the root epidermis, epidermal hairs termed root hairs are common and are specialized for the absorption of water and mineral nutrients. In plants with secondary growth , the epidermis of roots and stems is usually replaced by a periderm through the action of a cork cambium .
The function of all root hairs is to collect water and mineral nutrients in the soil to be sent throughout the plant. In roots, most water absorption happens through the root hairs. The length of root hairs allows them to penetrate between soil particles and prevents harmful bacterial organisms from entering the plant through the xylem vessels. [1]
The amount of water lost by a plant also depends on its size and the amount of water absorbed at the roots. Factors that effect root absorption of water include: moisture content of the soil, excessive soil fertility or salt content, poorly developed root systems, and those impacted by pathogenic bacteria and fungi such as pythium or rhizoctonia.
The mechanisms by which mycorrhizae increase absorption include some that are physical and some that are chemical. Physically, most mycorrhizal mycelia are much smaller in diameter than the smallest root or root hair, and thus can explore soil material that roots and root hairs cannot reach, and provide a larger surface area for absorption.
The Casparian strip, a cell wall outside the stele but in the root, prevents passive flow of water and nutrients, helping to regulate the uptake of nutrients and water. Xylem moves water and mineral ions in the plant and phloem accounts for organic molecule transportation. Water potential plays a key role in a plant's nutrient uptake. If the ...
Root Hairs – very small roots, often one cell wide, that do most of the water and nutrient absorption. Secondary – roots forming off of the primary root; often called branch roots. Taproot – a primary root that more-or-less enlarges and grows downward into the soil.