Alterations in protein expression pattern induced by different gravitational stimuli in roots of Arabidopsis Thaliana

Abstract

Plants will be an essential part of future Life Support Systems, which enable long duration human spaceflight and colonisation of other planets. For this reason we have to understand plant’s gravitational response towards a deviation from the vertical (e.g 90° alteration) and modifications/ behavioural changes under microgravity. The concrete objective of our work was to identify proteins, putative key proteins of the graviresponse, whose expression patterns are altered in Arabidopisis thaliana roots of 7 days old Col-0 wildtype seedlings after 30 minutes of simulated microgravity and 90° treatments. Total protein extracts were used for a quantitative analysis basing on 2D SDS-PAGE (KAMADA ET AL. 2005). All identified up- and downregulated proteins can be categorized in stress, transcriptional and translational modification, calcium signalling, auxin transporting and carbohydrate cycle and processing groups. Interestingly, some of the identified proteins exhibited an increased expression to a lack of gravity and a proper gravitational response. Our data clearly demonstrate several alterations of the proteome after 30 minutes of simulated microgravity and less changes after 30 minutes 90° stimulus. With the help of those insights and future experiments, we are able to prepare plants by breeding or genetic modification to grow, germinate and reproduce themselves in space with similar effectivity to earth.