During what stages of plant development is the coleoptile present?
Answers
Coleoptile, the sheath covering the plumule (embryonic shoot) in monocotyledonous seeds, is present only in embryonic stages.
Coleoptile is the sheath, covering the plumule in monocotyledonous seeds. The growth of the coleoptile is limited as as it does not have any apical meristem and its growth occurs due to cell elongation only.
The growing embryonic shoot is covered by coleoptile at the time of germination of the seed, which protects the apical meristem of the shoot from any injury that may be caused due to frictional forces of the soil particles.
The growing shoot comes out of the coleoptile by rupturing it after coming out of the soil as the latter can't grow any more in the absence of meristematic tissue. The growing shoot no longer needs protection in the absence of any frictional forces of soil particles when it has come out of the soil.