Thetitanmutants ofArabidopsisare disrupted in mitosis and cell cycle control during seed development

Liu, Chunming; Meinke, David W.

doi:10.1046/j.1365-313x.1998.00268.x

Cited by 219 publications

(183 citation statements)

References 95 publications

Supporting

Mentioning

174

Contrasting

Order By: Relevance

“…These results are consistent with a number of reports showing that inactivation of essential genes, including several in- volved in the formation or release of cohesion, does not block gametophyte development but rather cause alterations in embryo development (Liu and Meinke, 1998;Lam et al, 2005;Liu and Makaroff, 2006). It has been suggested that gametophytes may have a pool of mRNA or protein that can be utilized for the successful completion of the limited number of nuclear divisions required for gametophyte development (Liu and Meinke, 1998). Evidence in support of this hypothesis comes from the observation that transgenic plants expressing a separase RNA interference construct from the meiotic DMC1 promoter exhibit defects much earlier than T-DNA insertion lines (Liu and Makaroff, 2006).…”

Section: Proper Levels Of Ctf7 Are Essential For Mitosis In the Femalsupporting

confidence: 93%

“…However, these alterations do not appear to directly affect the function of the embryo sac or fertilization, as the mutation is transmitted normally through female gametophytes (Table I). These results are consistent with a number of reports showing that inactivation of essential genes, including several in- volved in the formation or release of cohesion, does not block gametophyte development but rather cause alterations in embryo development (Liu and Meinke, 1998;Lam et al, 2005;Liu and Makaroff, 2006). It has been suggested that gametophytes may have a pool of mRNA or protein that can be utilized for the successful completion of the limited number of nuclear divisions required for gametophyte development (Liu and Meinke, 1998).…”

Section: Proper Levels Of Ctf7 Are Essential For Mitosis In the Femalsupporting

confidence: 91%

See 1 more Smart Citation

Proper Levels of the Arabidopsis Cohesion Establishment Factor CTF7 Are Essential for Embryo and Megagametophyte, But Not Endosperm, Development

Jiang

Xia

et al. 2010

Plant Physiology

View full text Add to dashboard Cite

CTF7 is an essential gene in yeast that is required for the formation of sister chromatid cohesion. While recent studies have provided insights into how sister chromatid cohesion is established, less is known about how specifically CTF7 facilitates the formation of cohesion, and essentially nothing is known about how sister chromatid cohesion is established in plants. In this report, we describe the isolation and characterization of CTF7 from Arabidopsis (Arabidopsis thaliana). Arabidopsis CTF7 is similar to Saccharomyces cerevisiae CTF7 in that it lacks an amino-terminal extension, exhibits acetyltransferase activity, and can complement a yeast ctf7 temperature-sensitive mutation. CTF7 transcripts are found throughout the plant, with the highest levels present in buds. Seeds containing T-DNA insertions in CTF7 exhibit mitotic defects in the zygote. Interestingly, the endosperm developed normally in ctf7 seeds, suggesting that CTF7 is not essential for mitosis in endosperm nuclei. Minor defects were observed in female gametophytes of ctf7 1/2 plants, and plants that overexpress CTF7 exhibited female gametophyte lethality. Pollen development appeared normal in both CTF7 knockout and overexpression plants. Therefore, proper levels of CTF7 are critical for female gametophyte and embryo development but not for the establishment of mitotic cohesion during microgametogenesis or during endosperm development.The proper formation of sister chromatid cohesion and its subsequent release at the metaphase-to-anaphase transition is essential for the proper segregation of genetic material during cell division. It is critical for the compaction of chromosomes and their bipolar attachment to the spindle, DNA double-strand break repair, and the regulation of gene expression (for review, see Nasmyth and Haering, 2009). Sister chromatid cohesion is controlled by the cohesin complex, which consists of a heterodimer of Structural Maintenance of Chromosome (SMC) proteins, SMC1 and SMC3, Sister Chromatid Cohesion (SCC) protein SCC3, and SCC1, an a-kleisin protein. Perhaps the most widely accepted model of how cohesin functions has been referred to as the ring model, where the cohesin ring encircles the replicated sisters, holding them together until SCC1 cleavage by separase at the metaphase-to-anaphase transition opens the ring, allowing the release of the sister chromatids (for review, see Nasmyth and Haering, 2009).

show abstract

Section: Proper Levels Of Ctf7 Are Essential For Mitosis In the Femalsupporting

confidence: 93%

Section: Proper Levels Of Ctf7 Are Essential For Mitosis In the Femalsupporting

confidence: 91%

Proper Levels of the Arabidopsis Cohesion Establishment Factor CTF7 Are Essential for Embryo and Megagametophyte, But Not Endosperm, Development

Jiang

Xia

et al. 2010

Plant Physiology

View full text Add to dashboard Cite

show abstract

“…The green and white seeds were dissected from siliques and fixed in Hoyer's solution for 15 min (Liu and Meinke, 1998) and then examined and photographed with a Nikon ECL1PSE E600W microscope with Nomarski optics and equipped with a DXM1200 digital still camera. Images were processed with Adobe Photoshop version 7.0.…”

Section: Microscopy and Photographymentioning

confidence: 99%

LEUNIG_HOMOLOGandLEUNIGPerform Partially Redundant Functions during Arabidopsis Embryo and Floral Development

2008

View full text Add to dashboard Cite

Transcription corepressors play important roles in animal and plant development. In Arabidopsis (Arabidopsis thaliana), LEUNIG (LUG) and LEUNIG_HOMOLOG (LUH ) encode two highly homologous proteins that are similar to the animal and fungal Gro/Tup1-type corepressors. LUG was previously shown to form a putative corepressor complex with another protein, SEUSS (SEU), and to repress the transcription of AGAMOUS in floral organ identity specification. However, the function of LUH is completely unknown. Here, we show that single luh loss-of-function mutants develop normal flowers, but lug; luh double mutants are embryo lethal, uncovering a previously unknown function of LUG and LUH in embryonic development. In addition, luh/1 enhances the floral phenotype of lug, revealing a minor role of LUH in flower development. Functional diversification between LUH and LUG is evidenced by the inability of 35STLUH overexpression to rescue lug mutants and by the opposite expression trends of LUG and LUH in response to biotic and abiotic stresses. The luh-1 mutation does not enhance the defect of seu in flower development, but LUH could directly interact with SEU in yeast. We propose a model that explains the complex relationships among LUH, LUG, and SEU. As most eukaryotes have undergone at least one round of whole-genome duplication during evolution, gene duplication and functional diversification are important issues to consider in uncovering gene function. Our study provides important insights into the complexity in the relationship between two highly homologous paralogous genes.

show abstract

“…This type of interaction between the respective sizes of the endosperm and of the embryo has been inferred from studies of other mutants in Arabidopsis, maize, and rice (Oryza sativa). The Arabidopsis mutants titan 3 (Liu and Meinke, 1998), fis1/medea, fis2 (Chaudhury et al, 1997;Sørensen et al, 2001), demeter (Choi et al, 2002), and spätzle (Sørensen et al, 2002), primarily affected in endosperm development, produce viable embryos with reduced growth that develop into normallooking plants. In maize and rice, the endosperm stores reserves of the seed.…”

Section: Regulation Of Endosperm Size By Iku Might Control Embryo Sizmentioning

confidence: 99%

Arabidopsis haiku Mutants Reveal New Controls of Seed Size by Endosperm

et al. 2003

View full text Add to dashboard Cite

In flowering plants, maternal seed integument encloses the embryo and the endosperm, which are both derived from double fertilization. Although the development of these three components must be coordinated, we have limited knowledge of mechanisms involved in such coordination. The endosperm may play a central role in these mechanisms as epigenetic modifications of endosperm development, via imbalance of dosage between maternal and paternal genomes, affecting both the embryo and the integument. To identify targets of such epigenetic controls, we designed a genetic screen in Arabidopsis for mutants that phenocopy the effects of dosage imbalance in the endosperm. The two mutants haiku 1 and haiku 2 produce seed of reduced size that resemble seed with maternal excess in the maternal/paternal dosage. Homozygous haiku seed develop into plants indistinguishable from wild type. Each mutation is sporophytic recessive, and double-mutant analysis suggests that both mutations affect the same genetic pathway. The endosperm of haiku mutants shows a premature arrest of increase in size that causes precocious cellularization of the syncytial endosperm. Reduction of seed size in haiku results from coordinated reduction of endosperm size, embryo proliferation, and cell elongation of the maternally derived integument. We present further evidence for a control of integument development mediated by endosperm-derived signals.In flowering plants, the two female gametes, the egg cell and the central cell, are fertilized by one of the two male gametes delivered by the pollen tube. The zygotic product of the fusion of one male gamete with the egg cell develops into the embryo of the daughter plant. The fertilized central cell develops as the endosperm that nurtures embryo development. In most species, endosperm development is initiated by a proliferative syncytial phase accompanied by cell growth that generates a large multinucleate cell (Olsen, 2001; Berger, 2003). This syncytium is partitioned into individual cells by a specific type of cytokinesis called cellularization. In cereal species, the cellular endosperm stores the reserves of the seed during a phase marked by endoreduplication. Although the endosperm does not store the reserves of the seed in Arabidopsis, it most probably controls the flux of nutrients delivered by the vascular tissue of the mother to the embryo and protects the embryo from physical and osmotic stresses.Because the embryo is surrounded by the endosperm, which, in turn, is enclosed within the ovule integument, these three structures must coordinate their development to produce a mature seed of the appropriate size. The endosperm plays a central role in the control of seed size as indicated by a series of experiments in Arabidopsis and maize (Zea mays), where the dosage balance between maternal and paternal genomes was perturbed (Lin, 1984;Kermicle and Allemand, 1990;Scott et al., 1998). In most flowering plants, the endosperm contains two maternal copies and one paternal copy of the genome (2m/1p). In Arabidop...

show abstract

Thetitanmutants ofArabidopsisare disrupted in mitosis and cell cycle control during seed development

Cited by 219 publications

References 95 publications

Proper Levels of the Arabidopsis Cohesion Establishment Factor CTF7 Are Essential for Embryo and Megagametophyte, But Not Endosperm, Development

Proper Levels of the Arabidopsis Cohesion Establishment Factor CTF7 Are Essential for Embryo and Megagametophyte, But Not Endosperm, Development

LEUNIG_HOMOLOGandLEUNIGPerform Partially Redundant Functions during Arabidopsis Embryo and Floral Development

Arabidopsis haiku Mutants Reveal New Controls of Seed Size by Endosperm

Contact Info

Product

Resources

About