RECYCLING THE GREEN – How Chlorophyll Disappears

In search of traces of the green plant pigment: An investigation of chlorophyll breakdown and its enigmatic degradation products during autumnal senescence of local higher plants

The appearance of the green plant pigments in spring and their disappearance in the autumnal foliage of deciduous trees and in ripening fruit is probably one of the most colourful and fascinating natural phenomena on earth, observable even from outer space. Despite its ecological importance, the controlled degradation process remained enigmatic until about twenty years ago.

Based on world’s leading chemical contributions to the subject of chlorophyll degradation of the Kräutler group at the University of Innsbruck, and this group’s broad chemical and technical know-how, interested pupils will have the opportunity to contribute to recent and ongoing research in this area. In collaboration with teachers and scientists they will be encouraged to put their own creativity into practice.

We planed to observe the colours of senescent leaves as well as ripening fruit and investigate what’s behind all this. Chlorophyll breakdown is a part of a recycling strategy of higher plants to recover essential minerals (such as that of nitrogen). Therefore the phototoxic chlorophyll has to be transformed into colourless catabolites, which were considered to be a waste product. However, our recent findings on apples, pears and bananas revealed an unexpected diversity of chlorophyll breakdown and led to the question: Do chlorophyll catabolites have a biological function?

This project aims to provide high school students an exciting approach to science. Together with our two school partners, the Bundesrealgymnasium Adolf-Pichler-Platz (APP) and the Katholisches Oberstufenrealgymnasium Kettenbrücke (KORG), we offer around 230 pupils a closer contact to state-of-the-art research at the Institute of Organic Chemistry of the University of Innsbruck. The collaboration between university and school would be implemented in three modules of increasing difficulty. The students would be involved according to their personal skills.

The Institute of Botany at the University of Innsbruck will be our competent partner for plant selection and identification at Innsbruck’s botanical gardens.

This project has been completed.