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Record Details

Record 24 of 98
Gravitropism in caulonemata of the moss Pottia intermedia
Author and Affiliation:
Chaban, C. I.(Ukrainian National Academy of Sciences, Lviv, Ukraine)
Kern, V. D.
Ripetskyj, R. T.
Demkiv, O. T.
Sack, F. D.
Abstract: The gravitropism of caulonemata of Pottia intermedia is described and compared with that of other mosses. Spore germination produces primary protonemata including caulonemata which give rise to buds that form the leafy moss plant, the gametophore. Primary caulonemata are negatively gravitropic but their growth and the number of filaments are limited in the dark. Axenic culture of gametophores results in the production of secondary caulonemata that usually arise near the leaf base. Secondary protonemata that form in the light are agravitropic. Secondary caulonemata that form when gametophores are placed in the dark for several days show strong negative gravitropism and grow well in the dark. When upright caulonemata are reorientated to the horizontal or are inverted, upward bending can be detected after 1 h and caulonemata reach the vertical within 1-2 d. Clear amyloplast sedimentation occurs 10-15 minutes after horizontal placement and before the start of upward curvature. This sedimentation takes place in a sub-apical zone. Amyloplast sedimentation also takes place along the length of upright and inverted Pottia protonemata. These results support the hypothesis that amyloplast sedimentation functions in gravitropic sensing since sedimentation occurs before gravitropism in Pottia and since the location and presence of a unique sedimentation zone is conserved in all four mosses known to gravitropic protonomata.
Publication Date: Jan 01, 1998
Document ID:
20040089208
(Acquired Sep 07, 2004)
Subject Category: LIFE SCIENCES (GENERAL)
Document Type: Journal Article
Publication Information: Journal of bryology (ISSN 0373-6687); Volume 20; 2; 287-99
Publisher Information: United Kingdom
Contract/Grant/Task Num: UK4-000; NAG10-0179; SP4064017
Financial Sponsor: NASA Kennedy Space Center; Cocoa Beach FL United States
Description: In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: BRYOPHYTES; GRAVITROPISM; MULTIMEDIA; PLASTIDS; DARKNESS; ELECTRON MICROSCOPY; EXOBIOLOGY; MICROSCOPY; PLANTS (BOTANY); SPORES; TIME DEPENDENCE
Other Descriptors: BRYOPSIDA/GROWTH & DEVELOPMENT/ULTRASTRUCTURE; GRAVITROPISM/PHYSIOLOGY; PLASTIDS/PHYSIOLOGY/ULTRASTRUCTURE; COMPARATIVE STUDY; DARKNESS; MICROSCOPY, ELECTRON; MICROSCOPY, VIDEO; SPORES; SUPPORT, NON-U.S. GOV'T; SUPPORT, U.S. GOV'T, NON-P.H.S; TIME FACTORS; NASA DISCIPLINE PLANT BIOLOGY; NON-NASA CENTER
Availability Source: Other Sources
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