Subdiffraction-resolution live-cell imaging for visualizing thylakoid membranes

Journal Article · 29 July 2018 · The Plant Journal

DOI: https://doi.org/10.1111/tpj.14021 · OSTI ID:1559159

Iwai, Masakazu  ^[1]; Roth, Melissa S. ^[2]; Niyogi, Krishna K. ^[1]

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1. Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720 USA; Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley CA 94720-3102 USA
2. Department of Plant and Microbial Biology, Howard Hughes Medical Institute, University of California, Berkeley CA 94720-3102 USA

© 2018 The Authors The Plant Journal © 2018 John Wiley & Sons Ltd The chloroplast is the chlorophyll-containing organelle that produces energy through photosynthesis. Within the chloroplast is an intricate network of thylakoid membranes containing photosynthetic membrane proteins that mediate electron transport and generate chemical energy. Historically, electron microscopy (EM) has been a powerful tool for visualizing the macromolecular structure and organization of thylakoid membranes. However, an understanding of thylakoid membrane dynamics remains elusive because EM requires fixation and sectioning. To improve our knowledge of thylakoid membrane dynamics we need to consider at least two issues: (i) the live-cell imaging conditions needed to visualize active processes in vivo; and (ii) the spatial resolution required to differentiate the characteristics of thylakoid membranes. Here, we utilize three-dimensional structured illumination microscopy (3D-SIM) to explore the optimal imaging conditions for investigating the dynamics of thylakoid membranes in living plant and algal cells. We show that 3D-SIM is capable of examining broad characteristics of thylakoid structures in chloroplasts of the vascular plant Arabidopsis thaliana and distinguishing the structural differences between wild-type and mutant strains. Using 3D-SIM, we also visualize thylakoid organization in whole cells of the green alga Chlamydomonas reinhardtii. These data reveal that high light intensity changes thylakoid membrane structure in C. reinhardtii. Moreover, we observed the green alga Chromochloris zofingiensis and the moss Physcomitrella patens to show the applicability of 3D-SIM. This study demonstrates that 3D-SIM is a promising approach for studying the dynamics of thylakoid membranes in photoautotrophic organisms during photoacclimation processes.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
• Grant/Contract Number: AC02-05CH11231; SC0018301
• OSTI ID: 1559159
• Journal Information: The Plant Journal, Journal Name: The Plant Journal Journal Issue: 1 Vol. 96; ISSN 0960-7412
• Publisher: Society for Experimental BiologyCopyright Statement
• Country of Publication: United States
• Language: English