Kavita Srivastava

Effect of severe drought on CO2 uptake by plants, carbon translocation, assimilation and its turnover in plant-soil system

The impact of multidimensional environmental stress on plants at a various level of their growth has been investigated. However, knowledge is limited to which extent plants are able to allocate carbon (C) even during severe drought.We examined the idea that plant-soil relationship can be explained by total C input by plants and it’s cycling in the plant soil dynamics. Lipids are investigated as a key compound class in C cycling which protect plant from various environmental stress. However the adaptation capacity of plant lipids to severe remains unclear. Extreme climate change effects on the chemical compositions of lipid molecules which may depend on the plant species specific differences in the quantity of C input. Hence, present study is conducted to determine the impact of severe drought on the chemical composition of lipid. This project allows for the first time to trace changes in the chemical composition of lipids in two different plants communities, grassland and heath, grown on soil which were exposed to annual drought treatment or ambient conditions since 2005, while both treatment were exposed to severe drought (14 weeks) in 2011.Two pre-treatments were used with annual drought and control conditions to compare adoption of plant species to drought conditions. Triple 13CO2 labeling experiment (with each labeling at different stages of drought (0, 5th and 9th week) were performed in summer 2011 for the assessment of long term drought effects on C dynamics under field conditions. Samples are investigated for modifications of lipid composition affected by drought as well as 13C tracing at a molecular level for individual lipid fractions, like fatty acids and alkanes via compound-specific isotope analyses.