Nuclei in motion: movement and positioning of plant nuclei in development, signaling, symbiosis, and disease

Abstract

While textbook figures imply nuclei as resting spheres at the center of idealized cells, this picture fits few real situations. Plant nuclei come in many shapes and sizes, and can be actively transported within the cell. In several contexts, this nuclear movement is tightly coupled to a developmental program, the response to an abiotic signal, or a cellular reprogramming during either mutualistic or parasitic plant–microbe interactions. While many such phenomena have been observed and carefully described, the underlying molecular mechanism and the functional significance of the nuclear movement are typically unknown. Here, we survey recent as well as older literature to provide a concise starting point for applying contemporary molecular, genetic and biochemical approaches to this fascinating, yet poorly understood phenomenon.

Cell Wall Maturation of Arabidopsis Trichomes Is Dependent on Exocyst Subunit EXO70H4 and Involves Callose Deposition

“…Other phenomena observed can also be explained by different mechanisms. It was shown previously in multiple cases that the nucleus moves toward places with massive secretion (for example, during plant-microbe interactions; Griffis et al, 2014). Also, microtubular structures are often present in active secretory plasma membrane domains, such as the mucilage secretion domain of the outer layer of Arabidopsis seed coat (McFarlane et al, 2008).…”

LINCing the eukaryotic tree of life – towards a broad evolutionary comparison of nucleocytoplasmic bridging complexes

“…The most striking among these is likely the journey of the pollen vegetative nucleus down the pollen tube towards the female reproductive apparatus (for a recent review of nuclear movement in plants, see e.g. Griffis et al, 2014). It has been shown that KAKU1, in conjunction with the SUN-WIP-WIT complex is involved in nuclear movement in fully developed root hairs, as well as in the shade-recovery aspect of the high-light avoidance response in leaves (Tamura et al, 2013).…”

Dynamic Changes in Plant Nuclear Organization in Response to Environmental and Developmental Signals

“…Nuclear movement occurs in multiple plant cell types and developmental processes, as well as in response to both biological and mechanical stimuli (Griffis et al, 2014, and references therein). Several recent papers have focused on two nuclear movement events: nuclear photorelocation (Kawashima and Berger, 2015;Suetsugu et al, 2015;Iwabuchi et al, 2016;Suetsugu et al, 2016aSuetsugu et al, , 2016b and male germ unit migration in pollen tubes Zhou et al, 2015c).…”

“…The ONM and INM are populated by a variety of membrane-associated proteins, and in particular the inner membrane hosts a specific subset of proteins (Starr and Fridolfsson, 2010;Meier et al, 2017). In addition to functioning in nuclear morphology, chromatin attachment, and likely signal transduction, plant NE-associated proteins are involved in nuclear positioning and movement within the larger cellular context (Griffis et al, 2014). While plant nuclear ultrastructure reveals an inner nuclear membrane-associated meshwork similar to the animal lamina, plant genomes do not encode obvious lamin homologs.…”