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THE EFFECT OF COTYLEDONS ON CHLOROPLAST DEVELOPMENT IN PRIMARY LEAVES OF PHASEOLUS VULGARIS
Author(s) -
WHATLEY JEAN M.
Publication year - 1977
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1977.tb02180.x
Subject(s) - phaseolus , biology , chloroplast , germination , plastid , cotyledon , dormancy , botany , embryo , agar , agar plate , microbiology and biotechnology , bacteria , biochemistry , genetics , gene
Summary When seeds of Phaseolus vulgaris are allowed to develop normally in fruits on the mature plant, the plastids in the primary leaves of the embryo within the seed do not develop into mature chloroplasts. However, when the developing seeds are removed from the parent plants, the cotyledons detached, and the embryonic axes grown on agar, primary leaf plastids differentiate into mature chloroplasts within 7 days. In embryos with attached cotyledons, and similarly grown for a week on agar, plastids fail to differentiate. In primary leaves of dormant seeds allowed to germinate on agar, lamellar development begins earlier in seedlings from which the cotyledons have been removed than in those with attached cotyledons, although there is no significant difference between the two groups of seedlings in the time required for the chloroplasts to become fully mature. Plastid differentiation in primary leaves of developing seeds of Phaseolus therefore appears to be inhibited initially by the presence of the cotyledons. This inhibitory effect apparently declines during seed ripening and dormancy.