Cell-type-specific disruption and recovery of the cytoskeleton in Arabidopsis thaliana epidermal root cells upon heat shock stress

Summary. The cytoskeleton in plant cells plays an important role in controlling cell shape and mediating intracellular signalling. However, almost nothing is known about the reactions of cytoskeletal elements to heat stress, which represents one of the major environmental challenges for plants. Here we show that living epidermal root cells of Arabidopsis thaliana could cope with short-term heat shock stress showing disruption and subsequent recovery of microtubules and actin microfilaments in a time-dependent manner. Time-lapse imaging revealed a very dynamic behavior of both cytoskeletal elements including transient depolymerization and disassembly upon heat shock (40–41 °C) followed by full recovery at room temperature (20 °C) within 1–3 h. Reaction of microtubules, but not actin filaments, to heat shock was dependent on cell type and developmental stage. On the other hand, recovery of actin filaments, but not microtubules, from heat shock stress was dependent on the same parameters. The relevance of this adaptive cytoskeletal behavior to intracellular signalling is discussed. Correspondence and reprints: Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115 Bonn, Federal Republic of Germany.