Hexachlorocyclohexane inhibits calmodulin-dependent Ca2+-ATPase activity in rice shoot membranes

Salimath, B. P. ; Sharada, R. ; Karanth, N. G. K. ; Shetty, H. S. ; Majumder, S. K. (1988) Hexachlorocyclohexane inhibits calmodulin-dependent Ca2+-ATPase activity in rice shoot membranes Pesticide Biochemistry and Physiology, 31 (2). pp. 146-154. ISSN 0048-3575

Full text not available from this repository.

Official URL: http://linkinghub.elsevier.com/retrieve/pii/004835...

Related URL: http://dx.doi.org/10.1016/0048-3575(88)90016-8


Inclusion of hexachlorocyclohexane (HCH), a chlorinated insecticide, or calmodulin antagonists during the germination of paddy retarded the growth of the plant. Retardation of plant growth was accompanied by in vivo inhibition of Ca2+-ATPase activity by HCH and calmodulin antagonists. Bromophos, a phosphatic insecticide, had no significant effect either on growth or on the enzyme activity. HCH inhibited Ca2+-ATPase activity in vitro (IC50=20 μM) and in vivo (IC50=1.7 mM) in a dose-dependent manner. Likewise chloropromazine inhibited the enzyme activity in vivo with an IC50=50 to 80μM. Growth retardation and enzyme inhibition caused by HCH was reversed when the insecticide was withdrawn from the germinating medium. Similarly, enzyme inhibition due either to calmodulin antagonists or to HCH was overcome by the addition of excess calmodulin to the assay system. Inclusion of crude calmodulin from rice shoots increased Ca2+-ATPase activity by 112% suggesting the calmodulin-dependent regulation of the enzyme activity. These results, apart from demonstrating the role of Ca2+ and calmodulin in the regulation of plant growth and of Ca2+-ATPase activity, also suggest a possible mechanism of phytotoxic action of HCH in vivo.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:46711
Deposited On:06 Jul 2011 07:02
Last Modified:06 Jul 2011 07:02

Repository Staff Only: item control page