The Influence of Fluctuating Light Condition on Photosynthetic Acclimation in Arabidopsis Thaliana

Abstract

Photoacclimation is a process by which photosynthetic capacity is regulated in response to environmental adjustments in terms of light regime. Photoacclimation is essential in determining the photosynthetic capacity to optimize light use and to avoid potentially damaging effects. Previous work in our laboratory has identified a gene, gpt2 (At1g61800) that is essential for plants to acclimate to an increase and decrease of growth irradiance, separately. To investigate the photoacclimation ability towards fluctuating natural light condition in Arabidopsis thaliana, photosynthetic capacity was measured in plants of the accession Wassileskija (WS) and in plants lacking expression of the gene At1g61800 (WS-gpt2). The experiment was carried out over a time span from early Autumn to early Spring season in 2010-2011 and 2011-2012. The seedlings were grown in an unheated greenhouse in Manchester, UK without supplementary lighting. Gas exchange measurements, chlorophyll fluorescence analysis and chlorophyll content estimation were performed on WS and WS-gpt2 and it showed that both sets of plants could acclimate to fluctuating natural light condition. Therefore, it is suggested that the mechanisms of acclimation in a separate growth light condition is mechanistically distinct than the mechanism under fluctuating natural light condition.