Arabidopsis Kinesins HINKEL and TETRASPORE Act Redundantly to Control Cell Plate Expansion during Cytokinesis in the Male Gametophyte

Abstract

Asymmetric cell division at pollen mitosis I (PMI) is required to specify the differential fate of the daughter vegetative and generative cells. Cytokinesis at PMI displays specialized features, and it has been suggested that there might be distinct molecular pathways underpinning different modes of cytokinesis in plants. Activation of the NACK-PQR MAP kinase signaling pathway, which is essential for somatic cell cytokinesis in tobacco, depends upon the NACK1 and NACK2 kinesin-related proteins. Their Arabidopsis orthologs, HINKEL (HIK) and TETRASPORE (TES), were reported to be essential for cytokinesis in somatic cells and in microsporocytes, respectively. More recently, HIK and TES were shown to have a functionally redundant role in female gametophytic cytokinesis. We report here that HIK and TES are co-expressed in microspores and developing pollen, and, through analysis of microspore and pollen development in double heterozygote mutants, the occurrence of cell plate expansion defects during cytokinesis at PMI. The data demonstrate a functionally redundant role for HIK and TES in cell plate expansion during male gametophytic cytokinesis, extending the concept that different modes of cytokinesis are executed by a common signaling pathway, but reinforcing the individuality of gametophytic cytokinesis in its requirement for either TES or HIK.

NACK Kinesin Is Required for Metaphase Chromosome Alignment and Cytokinesis in the Moss <i>Physcomitrella Patens</i>

“…2A). These results suggest that PpNACK-a, -b, and -c function redundantly in protonemal cells, which is similar to the function of Arabidopsis' NACKs (HINKEL and TETRA-SPORES) (Oh et al, 2008;Tanaka et al, 2004).…”

Pollen Semi-Sterility1Encodes a Kinesin-1–Like Protein Important for Male Meiosis, Anther Dehiscence, and Fertility in Rice

“…These functions are highly relevant to male fertility in both animals and plants (Chen et al, 2002;Macho et al, 2002;Yang et al, 2003;Gandhi et al, 2004;Tanaka et al, 2004;Oh et al, 2008). We reasoned that this kinesin gene most likely represents the candidate PSS1.…”

“…Bivalents in the mutant meiocytes fail to align at the metaphase I plate properly, with some bivalents lagging behind in their movement to the metaphase I plate (Chen et al, 2002). Arabidopsis TETRASPORE (TES)/STUD/NACK2 and NACK1/HINKEL are kinesin-like proteins that have overlapping functions essential for regulating meiotic cytokinesis (Tanaka et al, 2004;Oh et al, 2008). PAKRP1/Kinesin-12A and PAKRP1L/Kinesin-12B also jointly play a critical role in the organization of phragmoplast microtubules and cell plate formation during male meiotic cytokinesis (Lee et al, 2007).…”

SIDECAR POLLENsuggests a plant-specific regulatory network underlying asymmetric microspore division in Arabidopsis

“…20 However, cytoplasmic partitioning (cytokinesis) between two daughter nuclei is incomplete leaving both nuclei in the same cytoplasm without the germ cell segregated. Similarly binucleate pollen grains resulting from failed cytokinesis have also been reported for double mutants in two redundant gene pairs encoding the kinesin-related proteins HINKEL and TETRASPORE 21 and the phragmoplast associated KINESIN-12A and KINESIN-12B. 22 These mutants highlight the importance of cytokinesis and its potential role in the segregation of germ cell fate determinants that promote differential gene expression between two is microtubule-dependent and involves a highly conserved molecular player with an ancient origin and role in regulating microtubule dynamics.…”