ISSN:
1573-5087
Keywords:
Cotton fibres
;
Gossypium spp.
;
Ca2+
;
ABA
;
O-diphenol oxidase
;
calmodulin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract This work is an investigation of the influence of ABA and calcium on soluble and wall-bound activities of peroxidase and O-diphenol oxidase of cotton fibres at the stages of primary and secondary wall development, during incubation of intact fibres for 3h at 28°C. ABA (10 μM) caused marked inhibition of enzyme activities in both the fractions, whereas calcium (1 mM) was promotory. The incorporation of 1 mM EGTA (a calcium chelator) and chlorpromazine (10 μg cm−3) (a calmodulin antagonist) resulted in decreased enzyme activities suggesting regulation of enzyme synthesis and/or secretion to the cell wall by calcium-calmodulin. As a general trend, the relative effect of Ca2+ on the activity of peroxidase in the wall was much greater than on the soluble activity, but this was not true of O-diphenol oxidase. It is inferred that ABA inhibits enzymic activities by inhibiting calmodulin synthesis or its mobilization to sites of action.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00024070
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