Co-localization of mitochondria with chloroplasts is a light-dependent reversible response

Abstract

Co-localization of mitochondria with chloroplasts in plant cells has long been noticed as beneficial interactions of the organelles to active photosynthesis. Recently, we have found that mitochondria in mesophyll cells of Arabidopsis thaliana expressing mitochondrion-targeted green fluorescent protein (GFP) change their distribution in a lightdependent manner. Mitochondria occupy the periclinal and anticlinal regions of palisade cells under weak and strong blue light, respectively. Redistributed mitochondria seem to be rendered static through co-localization with chloroplasts. Here we further demonstrated that distribution patterns of mitochondria, together with chloroplasts, returned back to those of dark-adapted state during dark incubation after blue-light illumination. Reversible association of the two organelles may underlie flexible adaptation of plants to environmental fluctuations. ©2010 Landes Bioscience.