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ABSTRACT Of the three types of cytoskeleton known in animals—actin, microtubules, and intermediate filaments—only actin and microtubules exist in plants. Both play important roles in cellular shaping, organelle movement, organization of the endomembrane system, and cell signaling. An emerging, but often overlooked role of the plant cytoskeleton is its dynamic and mutually influential interaction with the nucleus. Here, we summarize recent advances in understanding the role of the cytoskeleton in plant nuclear movement in different biological contexts, a role for nuclear envelope‐associated proteins in reorganizing the actin and microtubule cytoskeleton, and the molecular nature of the nucleus‐cytoskeleton interface and specific proteins contributing to it. In animals, the nucleoskeleton consists of the nuclear lamina, an intermediate‐filament meshwork underlying the nuclear envelope. Plants have evolved an equivalent of this structure, built by different types of proteins. Here, we highlight recent advances in understanding its filamentous organization, newly discovered protein interactions connecting it to nuclear pores, and exciting new evidence that—just like the animal lamina—the plant lamina is involved in chromatin reorganization and epigenetic changes. Together, these new developments create new opportunities toward a deeper understanding of this important regulatory connection between the cytoskeleton and the cell's largest organelle. 

The linker of nucleoskeleton and cytoskeleton (LINC) complex is a protein complex spanning the inner and outer membranes of the nuclear envelope. Outer nuclear membrane KASH proteins interact in the nuclear envelope lumen with inner nuclear membrane SUN proteins. The paralogous Arabidopsis KASH proteins SINE1 and SINE2 function during stomatal dynamics induced by light–dark transitions and ABA. Previous studies have shown F-actin organization, cytoplasmic calcium (Ca 2+ ) oscillations, and vacuolar morphology changes are involved in ABA-induced stomatal closure. Here, we show that SINE1 and SINE2 are both required for actin pattern changes during ABA-induced stomatal closure, but influence different, temporally distinguishable steps. External Ca 2+ partially overrides the mutant defects. ABA-induced cytoplasmic Ca 2+ oscillations are diminished in sine2-1 but not sine1-1 , and this defect can be rescued by both exogenous Ca 2+ and F-actin depolymerization. We show first evidence for nuclear Ca 2+ oscillations during ABA-induced stomatal closure, which are disrupted in sine2-1 . Vacuolar fragmentation is impaired in both mutants and is partially rescued by F-actin depolymerization. Together, these data indicate distinct roles for SINE1 and SINE2 upstream of this network of players involved in ABA-based stomatal closure, suggesting a role for the nuclear surface in guard cell ABA signaling.