xylem vessels造句

• Systemic fungicides are taken up and redistributed through the xylem vessels.
• Root pressure may be important in refilling the xylem vessels.
• Watermark disease affects infected trees by occluding the xylem vessels, impeding circulation.
• The mycelium advances intracellularly through the xylem vessels and produce microconidia ( asexual spores ).
• Xylem vessels sometimes empty over winter.
• Exopolysaccharides are produced by bacteria and block xylem vessels, often leading to the death of the plant.
• Negative pressure potentials occur when water is pulled through an open system such as a plant xylem vessel.
• "' Tyloses "'are outgrowths on parenchyma cells of xylem vessels of secondary heartwood.
• Unlike the water-conducting xylem vessel elements that are dead when mature, sieve elements are living cells.
• The xylem vessels carrying water become plugged through the chelation of calcium cations by oxalate just as in the kidney.
• The xylem vessels are dead at maturity but are responsible for most water transport through the vascular tissue in stems and roots.
• As in blood circulation in animals, ( gas ) embolisms may form within one or more xylem vessels of a plant.
• As a result, the concentration of ions ( osmotica ) in the xylem vessels is more in comparison to the soil water.
• On the other hand, the plant might be able to tolerate limited growth of the fungus within xylem vessels, preceded by an endophytic association.
• Sulfate is actively taken up across the plasma membrane of the root cells, subsequently loaded into the xylem vessels and transported to the shoot by the transpiration stream.
• The xylem vessels at the base of a tree can't grow beyond a certain diameter, he says, because bubbles are more likely to form in big tubes.
• She has shown that membranes linking a tree's xylem vessels may swell or shrink in response to the concentration of charged molecules, called ions, dissolved in the water of the xylem.
• Xylem cells are specialised for conduction of water, and first appeared in plants during their transition to land in the Silurian period more than 425 million years ago ( see " xylem vessels.
• Physical characteristics, such as diameter and density of xylem vessels, is due to the plant s genetic makeup, but also many environmental factors as well ( for this experiment it was rainfall ).
• In summary, there are a couple of factors that limit the ability of a tree to pull water from the soil to the top . 1 ) The strength of xylem vessels to with stand the negative pressure creating by " sucking " the water up . 2 ) the amount of force available from transpiration to pull water to the top of a tree.