Exploring the functional role of the plant mitochondrial alternative oxidase during sublethal cadmium exposure in Arabidopsis thaliana

Abstract

... The main objective of the current work was to uncover the involvement of mitochondria and in particular AOX during the Cd-induced oxidative challenge in Arabidopsis thaliana using environmentally realistic Cd exposure conditions. To reveal acclimation-related responses, the applied Cd concentrations should be situated in a sublethal yet toxic range. Two environmentally realistic Cd concentrations (5 or 10 µM) were chronically applied to the roots of A. thaliana plants grown in hydroponics. Using an established phenotypic framework methodology, the impact of Cd on the ability of the plants to complete their life cycle was determined. Although vegetative (rosette) growth of Cd-exposed plants was drastically reduced in a dose-dependent manner, both concentrations led to similar reductions in inflorescence height and silique counts. All plants were able to flower and form siliques containing germinative seeds, which confirms the non-lethality of both 5 and 10 µM Cd for hydroponically grown and exposed A. thaliana plants (Chapter 3). These concentrations were used throughout the following experiments to study Cd toxicity within a short-term exposure period up to 72 h (Chapters 4, 5 and 6)....