Dynamics and Organization of Cortical Microtubules as Revealed by Superresolution Structured Illumination Microscopy. Issue 1 (31st March 2014)

• Record Type: Journal Article
• Authors: Komis, George; Mistrik, Martin; Šamajová, Olga; Doskočilová, Anna; Ovečka, Miroslav; Illés, Peter; Bartek, Jiri; Šamaj, Jozef
• Is Part Of: Plant physiology. Volume 165:Issue 1(2014)
• Page Start: 129
• Page End: 148
• Publication Date: 2014-03-31
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.114.238477
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : The dynamic organization of cortical microtubules in plant cells is uncovered using structured illumination superresolution microscopy . Abstract: Plants employ acentrosomal mechanisms to organize cortical microtubule arrays essential for cell growth and differentiation. Using structured illumination microscopy (SIM ) adopted for the optimal documentation of Arabidopsis ( Arabidopsis thaliana ) hypocotyl epidermal cells, dynamic cortical microtubules labeled with green fluorescent protein fused to the microtubule-binding domain of the mammalian microtubule-associated protein MAP4 and with green fluorescent protein-fused to the alpha tubulin6 were comparatively recorded in wild-type Arabidopsis plants and in the mitogen-activated protein kinase mutant mpk4 possessing the former microtubule marker. The mpk4 mutant exhibits extensive microtubule bundling, due to increased abundance and reduced phosphorylation of the microtubule-associated protein MAP65-1, thus providing a very useful genetic tool to record intrabundle microtubule dynamics at the subdiffraction level. SIM imaging revealed nano-sized defects in microtubule bundling, spatially resolved microtubule branching and release, and finally allowed the quantification of individual microtubules within cortical bundles. Time-lapse SIM imaging allowed the visualization of subdiffraction, short-lived excursions of the microtubule plus end, and dynamic instability behavior of both ends during free, intrabundle, or microtubule-templated microtubule growth and shrinkage. Finally, short, rigid, and nondynamic microtubule bundles in the mpk4 mutant were observed to glide along the parent microtubule in a tip-wise manner. In conclusion, this study demonstrates the potential of SIM for superresolution time-lapse imaging of plant cells, showing unprecedented details accompanying microtubule dynamic organization.