Sieve tubes definition of Sieve tubes in the Free Online Encyclopedia.

sieve tube [′siv ‚tüb]

(botany)

A phloem element consisting of a series of thin-walled cells arranged end to end, in which some sieve areas are more specialized than others.

Sieve Tube

a conducting element of flowering plants. A sieve tube is a monostichous strand stretched the length of the cells; the end walls of the cells bear sieve plates containing sieve areas, which have numerous perforations lined with callose. Simple, usually horizontal plates have one sieve area (pumpkin, ash), whereas complex, slanted plates have several sieve areas (linden, grape, passionflower, rice). Each segment of the sieve tubes is adjoined by a strand of narrow companion cells. As the tubes develop, the tonoplasts in the cells are destroyed, the cytoplasm mixes with the cell fluid, and the organelles and nucleus deteriorate.

Most plants have sieve tubes that function for one year. However, the sieve tubes of grapes function for two years, those of lindens for several years, and those of some palms for decades. At the end of the vegetative period the sieve perforations are completely covered with callose, as are both sides of the sieve plates. The mass of callose on the sieve plates is called definitive callus. After the sieve tubes and their companion cells cease functioning, they disorganize and are obliterated.

L. I. LOTOVA

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No references found	In the beans, the needle-shaped protein complexes are situated in so-called sieve tubes, where they control the plant's flow of sugar-bearing fluid. Legume proteins provide motion by Ramsayer, K. / Science News	Sierra Nevada de Mérida Sierra Nevada de Santa Marta Sierra, Justo Sierre Sieur Jean de Joinville Sieve sieve analysis sieve area Sieve Cell sieve cells sieve classification sieve deposition sieve diameter sieve elements sieve fraction sieve lobe sieve mesh sieve number sieve of Eratosthenes sieve plate sieve shaker sieve texture sieve tissue sieve tray Sieve Tube Sieve tubes sieve-tube member Sievers, Eduard Sievers, Wilhelm Sieversia sievert sieving Sieyes, Emmanuel Joseph Sieyès, Emmanuel Joseph Sieyès, Emmanuel-Joseph siffanto Sífnos Siforov, Vladimir Siforov, Vladimir Ivanovich sift Sifting Machine Sifton, Sir Clifford sig sig block sig quote sig virus Sigalionidae Siganidae Sigatoka SIGBUS SIGCAT	Sieve cells sieve classification sieve deposition sieve diameter sieve element sieve elements sieve fraction sieve graft sieve graft sieve graft sieve graft sieve graft sieve lobe sieve mesh sieve number Sieve of Eratosthenes sieve out sieve plate sieve plate Sieve plates Sieve plates Sieve principle sieve shaker sieve texture sieve tissue sieve tray sieve tube sieve tube Sieve tube element Sieve tube element Sieve tubes sieve-like sieve-like sieve-like sieve-tube element Sieve-tube member sieved sieved sieved sieved through sieved through sieved through Sieverodonetsk Sievers' J-Value Sievers, Eduard Sievers, Wilhelm Sieversia sievert sievert sievert sievert sievert Sievert (Sv) Sievert (Sv) Sievert (Sv) Sieverts Sieverts Sieverts Sieverts Per Hour sieves sieves

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In the beans, the needle-shaped protein complexes are situated in so-called sieve tubes, where they control the plant's flow of sugar-bearing fluid.

Legume proteins provide motion by Ramsayer, K. / Science News

Sieve Tube (redirected from Sieve tubes)

Sieve Tube
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