Coleorhiza

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The coleorhiza or root sheath is a protective layer of tissue that surrounds the radicle (the embryonic primary root) in monocotyledon seeds. [1] During germination, the coleorhiza is the first part to grow out of the seed, growing through cell elongation. Soon afterwards, it is pierced through by the emerging primary root and then remains like a collar around the root base. Also the adventitious roots have a coleorhiza.

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In botany, a seed is a plant embryo and food reserve enclosed in a protective outer covering called a seed coat (testa). More generally, the term "seed" means anything that can be sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted.

<span class="mw-page-title-main">Root</span> Basal organ of a vascular plant

In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water.

<span class="mw-page-title-main">Radicle</span> Radicle forms the future root

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<span class="mw-page-title-main">Germination</span> Process by which an organism grows from a spore or seed

Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ferns, bacteria, and the growth of the pollen tube from the pollen grain of a seed plant.

<span class="mw-page-title-main">Hypocotyl</span> Plant part

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<span class="mw-page-title-main">Auxin</span> Plant hormone

Auxins are a class of plant hormones with some morphogen-like characteristics. Auxins play a cardinal role in coordination of many growth and behavioral processes in plant life cycles and are essential for plant body development. The Dutch biologist Frits Warmolt Went first described auxins and their role in plant growth in the 1920s. Kenneth V. Thimann became the first to isolate one of these phytohormones and to determine its chemical structure as indole-3-acetic acid (IAA). Went and Thimann co-authored a book on plant hormones, Phytohormones, in 1937.

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References

  1. Barrero, José M.; Talbot, Mark J.; White, Rosemary G.; Jacobsen, John V.; Gubler, Frank (June 2009). "Anatomical and Transcriptomic Studies of the Coleorhiza Reveal the Importance of This Tissue in Regulating Dormancy in Barley". Plant Physiology . 150 (2): 1006–1021. doi:10.1104/pp.109.137901. PMC   2689963 . PMID   19386806.

Definition of coleoptile : The plumule are enclosed in sheaths which are called coleoptile. They protect the plumule for future, as in future it develops into shoot.