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CALCIUM DELAYS THE ONSET OF CELL DIVISION AND RHIZOID ELONGATION IN GEMMAE OF THE CALCIFUGE FERN, VITTARIA GRAMINIFOLIA
Author(s) -
Sabba Robert P.,
Miller John H.
Publication year - 1993
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1993.tb15231.x
Subject(s) - rhizoid , gemma , biology , elongation , cell division , gametophyte , protonema , botany , fern , thallus , apical cell , cell , moss , biochemistry , pollen , materials science , metallurgy , ultimate tensile strength
Vittaria graminifolia gametophytes reproduce asexually by linear six‐celled propagules known as gemmae. It has been shown previously that asymmetric cell division and rhizoid elongation in gemmae are inhibited by millimolar concentrations of Ca + + . The present paper shows that millimolar Ca + + delays the onset of cell division at a point prior to mitosis, without affecting the maximal rate of cell division. Ca + + is most effective in delaying cell division when it is present during the first 24 hours of culture, 2 or 3 days before the initiation of cell division. Millimolar Ca + + inhibits rhizoid elongation by delaying its onset, while also reducing its maximal rate. Ca + + is also most effective in delaying rhizoid elongation during the first 24 hours of culture. Culture of gemmae on Ethylglycol‐bis‐(aminoethyl ether)‐N,N,N‘,N‘‐tetraacetic acid‐buffered media shows that the maximum frequency of cell division occurs at pCa 7, while for the initiation of rhizoid elongation, it occurs at pCa 5.