Silicon absorption by plants in response to the environment¹

ABSTRACT

Despite the importance given to Silicon in the relief of stress in cultivated plants, there are no experimental studies on abiotic stresses that address this function of Si in plants under natural environments, aiming to identify responses that would indicate acclimatisation to the conditions at their place of origin. The goal of this study was to answer the following questions: 1) Does abiotic stress increase Si absorption? 2) Does the presence of Si stimulate biomass production in natural environments? and 3) Do plants from different environments display differences in Si absorption? To do so, Eugenia punicifolia was selected as a study species since it has a wide distribution, occurring in three different physiognomies: Coastal Savanna, Dense Deciduous Shrubland and Seasonal Deciduous Forest. The Si absorption varied depending on the temperature and this was directly related to increases in dry matter production in E. punicifolia plants, suggesting that this may be a relief mechanism for temperature and water stresses. Differences in the response to stress conditions may be a result of the phenotypic plasticity which occurs in E. punicifolia and suggests that plasticity could be a useful asset in the use of Si fertilizer for crops.

Keywords
water stress; temperature; phenotypic plasticity; acclimatisation; relief