Microtubule involvement in stomatal dynamics

Stomatal dynamics have been investigated in terms of ion exchange involvements, turgor pressure fluctuations, and transcriptional changes, particularly in response to environmental stresses. However, the involvement of the cytoskeleton during this process, particularly concerning the role of microtubules (MTs), is a relatively new field of study. Qu et al. investigated the role of MTs in ABA- and light-induced stomatal responses. Stabilizing MTs with paclitaxel promoted light-induced stomatal opening, with guard cells exhibiting more organized and denser MT arrays, but this MT stabilization inhibited dark-induced closure. On the other hand, destabilizing MTs inhibited light-induced opening and abolished the MT network but did not affect dark-induced closure. ABA does disrupt MTs and the authors found that paclitaxel partially arrested ABA-induced closure and MT depolymerization. The ABA-insensitive pldα1 mutants were able to be rescued with cotreatment of ABA and oryzalin, but not oryzalin alone. These data suggest that MT reorganization is required but not sufficient for ABA-induced stomatal closure and that MTs are involved in stomatal opening. (Summary by Alecia Biel) Plant Growth Regulation 10.1007/s10725-017-0353-5.