Project R-4954

The cell wall and the apoplast as a primary defence strategy in plants exposed to cadmium (Research)

By 2050 the world's population is estimated to reach 9.1 billion, representing major challenges to develop a more sustainable agriculture and bio-based economy. Plants fulfil a key role in this via production of food, feed and raw materials for industry. However, their productivity is limited by environmental stress, such as cadmium (Cd), a widely spread toxic metal. Increased knowledge on Cd-induced effects in plants should safeguard their role in a sustainable future. Cd-induced phytotoxicity is linked to oxidative stress and as this may result in cellular damage, it is crucial to limit free Cd ions in the cell. Due to its direct contact with the environment, the plant cell wall is a primary target for Cd. The metal-binding capacity of the cell wall depends on negatively charged pectins that can be altered by Cd exposure. In addition, Cd induces cell wall remodelling in which the antioxidant ascorbate plays a crucial role, interconnecting the cell wall and Cd-induced cellular oxidative stress. An integrated study on the effects of environmentally realistic Cd exposure on cell wall properties is conducted using the model organism Arabidopsis thaliana and the crop Medicago sativa (alfalfa). The responses of the cell wall at the level of mineral content and distribution, proteomics, pectin biosynthesis and remodelling are investigated. This is related to the ascorbate content and downstream Cd-induced oxidative challenge ultimately linked to plant quality.

01 January 2014 - 31 December 2017