Related Experiment Videos
Gravity-regulated formation of the peg in developing cucumber seedlings
1Institute of Genetic Ecology, Tohoku University, Sendai, Japan.
Planta
|January 1, 1994
Summary
Peg formation in Cucurbitaceae seedlings is linked to gravity. Sedimented amyloplasts in the vascular transition region suggest a gravimorphogenetic mechanism similar to shoot gravitropism.
Area of Science:
- Plant biology
- Gravitropism
- Plant development
Background:
- Peg formation in Cucurbitaceae seedlings occurs in the vascular transition region (TR zone).
- This phenomenon has been proposed as a gravimorphogenetic response.
Purpose of the Study:
- To investigate the role of gravity in peg formation in Cucurbitaceae seedlings.
- To identify the cellular mechanisms involved in graviperception for peg development.
Main Methods:
- Cucumber seeds (Cucumis sativus L. cv. Burpee Hybrid II) were germinated horizontally at 24°C in the dark.
- Microscopic observation of amyloplasts (putative statoliths) in the TR zone at 36 and 48 hours post-imbibition.
Main Results:
- Peg initiation was visible 36 hours after imbibition in horizontally germinated seeds.
- Sedimented amyloplasts were observed in sheath and adjacent cortical cells of the TR zone.
- Cortical cells destined for peg development contained non-sedimented amyloplasts.
- By 48 hours, TR zone cells retained sedimented amyloplasts but lost gravity sensitivity.
Conclusions:
- Graviperception for peg formation in Cucurbitaceae seedlings likely involves sedimented amyloplasts, similar to shoot gravitropism.
- The TR zone cells may lose gravity sensitivity due to maturation after 48 hours.