Uni-Bayreuth grafik-uni-bayreuth



Effect of severe drought on the molecular composition of lipids in plants and soil in the temperate grassland of central Europe

Kavita Srivastava1, Anke Jentsch2, Guido Wiesenberg3
1 Agroecosystem Research, University of Bayreuth,Germany
2 Disturbance Ecology, University of Bayreuth, Germany
3 Agroecosystem Research, University of Bayreuth, Germany

P 3.4 in Ecosystems: Function and Services

Plants response to drought stress on carbon (c) uptake and its turnover in soil organic matter  has been well investigated however, knowledge is limited to which extent plants are able to allocate C during severe drought and its impact on the on the molecular lipid composition of plants and soil organic matter. Present study is conducted to determine the impact of severe drought on the chemical composition of lipid molecule (cell membrane and wax lipids). Lipids were investigated to response quickly on change in the environmental conditions whereas the ability is surely different for the individual plant species. Hence this project allows for the first time tracing changes in the chemical composition of lipids in two different  plants communities (3 grassland species and 2 heath species) grown on soil which were exposed to annual drought treatment since 2005. 13CO2 labeling experiment applied to measure differential c uptake that have not been conducted until increasing drought conditions to trace c uptake and translocation. The aim of this project is to investigate when c uptake does, when c translocation stops and how does mineralization of c in soil affected due to severe drought stress? Triple 13CO2 labeling experiment, with each labeling at different stages of drought  were performed in last summer 2011 for the assessment of long term drought effects on C dynamics under field conditions. Samples were investigated for modifications of ipid composition affected by drought as well as 13C tracing at a molecular level for individual lipid fractions, like fatty acids and alkenes via compound-specific isotope analyses. Our first result shows that due to effect of severe drought lipids become selectively enriched in soil of grassland than to heathland. Our preliminary results have special interest for plant derived lipids incorporation in below ground biomass.


last modified 2012-09-21