Heat production of root cells upon the dissipation of ion gradients on plasma membrane

• Published in: Thermochimica acta Vol. 309; no. 1; pp. 139 - 143
• Main Authors: Minibayeva, F.V., Gordon, L.Kh, Alyabyev, A.Ju, Rakhmatullina, D.F., Loseva, N.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 26.01.1998
• Subjects: Heat production; Ion transport; Respiration; Root cells; Ion transport; Respiration; Root cells; Heat production
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/S0040-6031(97)00349-3

The dissipation of ion gradients across plasma membranes contributes to the heat production by live cells. The aim of the present research is to determine the dependence of the rate of heat production by plant tissues on ion balance shifts, supposing a priori that the shifts are the beginning mechanism in adaptation to various stresses. Excised wheat roots subjected to prolonged incubation in different solutions served as objects for investigation. Two ion transporters ( K + H +- transporter nigericin and Ca 2+-ionophore A23187) shifted the ion homeostasis and induced distinct changes in the energy metabolism of plant tissues. Nigericin, which considerably increased the plasmalemma conductivity for protons and potassium, enhanced production of heat by root cells throughout the exposure. Prolonged incubation with A23187 was required to display its ion-transporting properties which were accompanied by a rise in the rate of heat release. The high rate of heat release and respiration in root cells exposed to ion transporters is a reflection of the ion-gradient dissipation and the increased energy expenditure for the activation of ATPase systems necessary for the restoration of ionophore-disturbed ion homeostasis.