Speaker
Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)
Yes
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
MSc
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Main supervisor (name and email)<br>and his / her institution
Dr. Tjaart PJ Krüger
University of Pretoria
Abstract content <br> (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>
The ultrafast transient dynamics of the main plant light-harvesting complex (LHCII) of spinach leaves were studied, using the technique of pump-probe spectroscopy. Explicitly, the excitation energy transfer processes within and amongst the protein-bound pigments (viz. chlorophylls and carotenoids), were investigated. These pigments are responsible for the absorption of solar photons, and transfer the electronic excitation energy on ultrafast timescales to nearby complexes, and eventually to a reaction center where charge separation is induced. Nature is designed in such a way that plants are self-protected against the damage of over-illumination by activating a number of processes which collectively contribute to non-photochemical quenching (NPQ). This poster will outline the information extracted from the South African National Laser Centre (NLC) pump-probe facility, in comparison to the data previously obtained from an ultrafast transient absorption spectroscopy setup at Vilnius University in Lithuania. The wavelengths investigated in both cases were 489 nm and 506 nm, specifically targeting the excited-state dynamics of Lutein1 & Neoxanthin and Lutein2 & Violaxanthin carotenoids, respectively. An intensity dependence study was performed in order to understand possible variations in energy transfer kinetics of the carotenoids and how these changes influence the fast process of NPQ. Global analysis and some target analysis of the transient absorption results were performed using the free Glotaran software.
