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Gravity-regulated formation of the peg in developing cucumber seedlingsIt has been proposed that peg formation in the vascular transition region (TR zone) between the hypocotyl and the root in Cucurbitaceae seedlings is a gravimorphogenetic phenomenon. Initiation of the peg became visible 36 h after imbibition when cucumber (Cucumis sativus L. cv. Burpee Hybrid II) seeds were germinated in a horizontal position at 24 degrees C in the dark. Simultaneously, sedimented amyloplasts (putative statoliths) were apparent in the sheath cells surrounding the vascular strands, and in the cortical cells immediately adjacent to them, in the TR zone. In contrast, the other cortical cells, some of which were destined to develop into the peg, contained amyloplasts which were not sedimented. These results suggest that the graviperception mechanism for peg formation may be like that of statoliths in shoot gravitropism. By 48 h following imbibition, the cells of the TR zone still had sedimented amyloplasts but had lost their sensitivity to gravity, possibly because of their maturation.
Document ID
20040090225
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
Authors
Takahashi, H.
(Institute of Genetic Ecology, Tohoku University Sendai, Japan)
Scott, T. K.
Date Acquired
August 21, 2013
Publication Date
January 1, 1994
Publication Information
Publication: Planta
Volume: 193
ISSN: 0032-0935
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NAGW-1842
CONTRACT_GRANT: 837907-7
Distribution Limits
Public
Copyright
Other
Keywords
NASA Program Space Biology
Non-NASA Center
NASA Discipline Number 40-50
NASA Discipline Plant Biology

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