Premium
Increased activity of aminopeptidase in the cotyledons of red light‐promoted lettuce seeds is controlled by the axis
Author(s) -
Leung David W. M.,
Bewley J. Derek
Publication year - 1983
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1983.tb06583.x
Subject(s) - imbibition , lactuca , aminopeptidase , endosperm , germination , enzyme , biology , cotyledon , botany , biochemistry , chemistry , leucine , amino acid
The first major reserves to be mobilized following germination of light‐promoted lettuce seeds ( Lactuca saliva L. cv. Grand Rapids) are the carbohydrates, largely mannans, located within the cell walls of the endosperm. When these have been depleted, the cotyledonary reserves are hydrolysed; the first of these to decline is protein. Water‐, salt‐ and ethanol‐soluble proteins are mobilized simultaneously, and coincident with their loss from the cotyledons there is an increase in aminopeptidase activity. The level of enzyme activity increases appreciably in irradiated seeds after about 30 h from the start of imbibition. Essential for this increase, at least initially, is the presence of the axis ‐ first to perceive the light stimulus, and then to produce and/or release a chemical promoter which diffuses into the cotyledons and effects the rise in enzyme activity. Protein synthesis in the cotyledons is a prerequisite for both development and maintenance of the increased aminopeptidase activity.