The activity of the plant inner membrane mitochondrial anion channel (PIMAC) is involved in metabolite shuttles and mitochondrial volume changes and could have a role in plant temperature tolerance. Our objectives were to in- vestigate (i) the occurrence and (ii) the temperature de- pendence of anion fluxes through PIMAC in mitochondria isolated from seedlings of three maize populations differing in terms of cold tolerance; and (iii) the relationships between the PIMAC activity kinetics and the level of cold tolerance. Populations were the source population (C0) and two populations divergently selected for high (C4H) and low (C4L) cold tolerance. Such divergently selected popula- tions are expected to share most of their genes, with the main exception of those genes controlling cold tolerance. Arrhenius plots of PIMAC chloride fluxes showed a linear temperature dependence when seedlings were grown at 25 or 14C, whereas a non-linear temperature dependence was found when seedlings were grown at 5C, with or with- out acclimation at 14C. The activation energy and other thermodynamic parameters of PIMAC activity varied depending on temperature treatments during seedling growth. When seedlings were grown at 14 and 5C with acclimation, PIMAC activity of the C4H population increased, while that of C4L declined, as compared with the activities of seedlings grown at 25C. These symmetric responses indicate that PIMAC activity changes are asso- ciated with genetically determined differences in the cold tolerance level of the investigated populations. We conclude that anion fluxes by PIMAC depend upon changes on growth temperature and are differentially related to the tolerance level of the tested populations.
A. De Santis, E. Frascaroli, E. Baraldi, F. Carnevali, P. Landi (2011). The Activity of the Plant Mitochondrial Inner Membrane Anion Channel (PIMAC) of Maize Populations Divergently Selected for Cold Tolerance Level is Differentially Dependent on the Growth Temperature of Seedlings. PLANT AND CELL PHYSIOLOGY, 52, 193-204 [10.1093/pcp/pcq189].
The Activity of the Plant Mitochondrial Inner Membrane Anion Channel (PIMAC) of Maize Populations Divergently Selected for Cold Tolerance Level is Differentially Dependent on the Growth Temperature of Seedlings
DE SANTIS, AURELIO;FRASCAROLI, ELISABETTA;BARALDI, ELENA;LANDI, PIERANGELO
2011
Abstract
The activity of the plant inner membrane mitochondrial anion channel (PIMAC) is involved in metabolite shuttles and mitochondrial volume changes and could have a role in plant temperature tolerance. Our objectives were to in- vestigate (i) the occurrence and (ii) the temperature de- pendence of anion fluxes through PIMAC in mitochondria isolated from seedlings of three maize populations differing in terms of cold tolerance; and (iii) the relationships between the PIMAC activity kinetics and the level of cold tolerance. Populations were the source population (C0) and two populations divergently selected for high (C4H) and low (C4L) cold tolerance. Such divergently selected popula- tions are expected to share most of their genes, with the main exception of those genes controlling cold tolerance. Arrhenius plots of PIMAC chloride fluxes showed a linear temperature dependence when seedlings were grown at 25 or 14C, whereas a non-linear temperature dependence was found when seedlings were grown at 5C, with or with- out acclimation at 14C. The activation energy and other thermodynamic parameters of PIMAC activity varied depending on temperature treatments during seedling growth. When seedlings were grown at 14 and 5C with acclimation, PIMAC activity of the C4H population increased, while that of C4L declined, as compared with the activities of seedlings grown at 25C. These symmetric responses indicate that PIMAC activity changes are asso- ciated with genetically determined differences in the cold tolerance level of the investigated populations. We conclude that anion fluxes by PIMAC depend upon changes on growth temperature and are differentially related to the tolerance level of the tested populations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
