Organisation and regulation of the cytoskeleton in plant programmed cell death

Abstract

Programmed cell death (PCD) involves precise integration of cellular responses to extracellular and intracellular signals during both stress and development. In recent years much progress in our understanding of the components involved in PCD in plants has been made. Signalling to PCD results in major reorganisation of cellular components. The plant cytoskeleton is known to play a major role in cellular organisation, and reorganization and alterations in its dynamics is a well known consequence of signalling. There are considerable data that the plant cytoskeleton is reorganised in response to PCD, with remodelling of both microtubules and microfilaments taking place. In the majority of cases, the microtubule network depolymerises, whereas remodelling of microfilaments can follow two scenarios, either being depolymerised and then forming stable foci, or forming distinct bundles and then depolymerising. Evidence is accumulating that demonstrate that these cytoskeletal alterations are not just a consequence of signals mediating PCD, but that they also may have an active role in the initiation and regulation of PCD. Here we review key data from higher plant model systems on the roles of the actin filaments and microtubules during PCD and discuss proteins potentially implicated in regulating these alterations.

Resolvase OsGEN1 Mediates DNA Repair by Homologous Recombination

“…Furthermore, disturbance of the cytoskeleton was found in osgen1 microspores. Tubulin and actin did not form grid structures and only showed fuzzy signals, confirming cell death of osgen1 microspores (Smertenko and Franklin-Tong, 2011;Supplemental Fig. S9).…”

The Actin-Related Protein2/3 Complex Regulates Mitochondrial-Associated Calcium Signaling during Salt Stress inArabidopsis

“…In plant cells, many extracellular stimuli trigger rapid changes in cytoskeletal organization, and these changes may serve as signals to regulate cellular responses, including programmed cell death (Wasteneys and Yang, 2004;Hussey et al, 2006;Smertenko and Franklin-Tong, 2011). Previous studies have shown that, in response to salt stress, the SOS pathway (Wang et al, 2007;Ye et al, 2013) and a pathway involving SOS3-like Calcium Binding Protein1, SOS2-like Protein Kinase5, and the plasma membrane H + -ATPase (Fuglsang et al, 2007) involve regulation of MF organization (Liu and Guo, 2011).…”

Self-Incompatibility-Induced Programmed Cell Death in Field Poppy Pollen Involves Dramatic Acidification of the Incompatible Pollen Tube Cytosol

“…In Brewer's yeast (Saccharomyces cerevisiae), CAP (Srv2p in yeast) localizes to actin patches (Lila and Drubin, 1997) and is required for the formation of F-actin bodies (Gourlay et al, 2004) in stressed, quiescent Brewer's yeast (Sagot et al, 2006). Several plant systems have been observed to exhibit F-actin reorganization during PCD, and it is thought that the polymeric status of actin acts as a dynamic, integrated feedback mechanism for the health status of a cell, with PCD signaling major alterations (Smertenko and Franklin-Tong, 2011). Drawing comparisons with a study providing a link between actin alterations and signaling to apoptosis in lymphocytes (Hao and August, 2005), it has been suggested that a similar scenario may operate in plant cells and that alterations to the plant actin cytoskeleton could potentially signal directly to PCD (Tian et al, 2009 …”