Effect of copper (II) ions on morpho-physiological and biochemical variables in Colobanthus quitensis

Abstract

Colobanthus quitensis is a species with a wide geographical distribution, including Antarctica. This species must endure a series of limiting abiotic factors in its habitats, such as, high metal ion concentrations. It has been described to inhabit areas where only metal-tolerant species can live. Therefore, it is postulated that the study of this species may provide information about copper tolerance mechanisms. We evaluated the effect of copper (II) ions (control, 100 and 500 µM) on C. quitensis seedlings in vitro, determining morpho-physiological and biochemical variables. Copper showed a significantly negative effect on the development of new shoots (500 µM) and floral apex appearance (100 µM). The analyzed Cu concentrations significantly affected leaf and root length and induced a significant increase in guaiacol peroxidase (G-POD) enzyme activity. The highest proline accumulation took place in seedlings subjected to 500 µM. Furthermore, this concentration induced a significant reduction in chlorophyll a content and exhibited oxidative stress evaluated through an increase in malondialde-hyde levels. This is the first study to demonstrate evidence of copper effects on morphological, physiological and biochemical variables in C. quitensis.