..., occasionally leading to formation of two embryos per seed. Furthermore, seed coat, and putatively also endosperm development, frequently initiated autonomously. Such induction of several features phenocopying distinct elements of apomixis by a single mutation is unusual and suggests that RH17 acts...

...Chloé Fourquin; Léna Beauzamy; Sophy Chamot; Audrey Creff; Justin Goodrich; Arezki Boudaoud; Gwyneth Ingram Seed development in angiosperms demands the tightly coordinated development of three genetically distinct structures. The embryo is surrounded by the endosperm, which is in turn enclosed...

...Léna Beauzamy; Chloé Fourquin; Nelly Dubrulle; Yann Boursiac; Arezki Boudaoud; Gwyneth Ingram In Arabidopsis , rapid expansion of the coenocytic endosperm after fertilisation has been proposed to drive early seed growth, which is in turn constrained by the seed coat. This hypothesis implies...

...Grégoire Denay; Audrey Creff; Steven Moussu; Pauline Wagnon; Johanne Thévenin; Marie-France Gérentes; Pierre Chambrier; Bertrand Dubreucq; Gwyneth Ingram In Arabidopsis seeds, embryo growth is coordinated with endosperm breakdown. Mutants in the endosperm-specific gene ZHOUPI ( ZOU ), which encodes...

.... However, genome-wide studies suggested other DNA methylation-dependent imprinting mechanisms. Here, we show that de novo RNA-directed DNA methylation (RdDM) regulates imprinting at specific loci expressed in endosperm. RdDM in somatic tissues is required to silence expression of the paternal allele...

...Qian Xing; Audrey Creff; Andrew Waters; Hirokazu Tanaka; Justin Goodrich; Gwyneth C. Ingram Seed production in angiosperms requires tight coordination of the development of the embryo and the endosperm. The endosperm-specific transcription factor ZHOUPI has previously been shown to play a key role...

...Elisabeth Hehenberger; David Kradolfer; Claudia Köhler The endosperm is a terminal seed tissue that is destined to support embryo development. In most angiosperms, the endosperm develops initially as a syncytium to facilitate rapid seed growth. The transition from the syncytial to the cellularized...

... that loss-of-function of the major DNA LIGASE I (AtLIG1) in Arabidopsis thaliana causes maternal effects in the endosperm, which is the seed tissue that nurtures embryo development. AtLIG1 expression is not imprinted and has a limited impact on imprinted gene expression. Genetic interaction analyses further...

... for correspondence( [email protected] ) * Present address: Rhodes College, 2000 N Parkway, Memphis, TN 38112, USA 19 8 2009 © 2009. 2009 Polycomb Endosperm Arabidopsis Imprinting ARABIDOPSIS FORMIN HOMOLOGUE 5 ( AtFH5 ) Parental genomic imprinting - the preferential expression...

...Suxin Yang; Niamh Johnston; Edmund Talideh; Steve Mitchell; Chris Jeffree; Justin Goodrich; Gwyneth Ingram During Arabidopsis seed development, the growing embryo invades and consumes the surrounding endosperm tissue. The signalling pathways that coordinate the separation of the embryo from...

... with the central cell and gives rise to the endosperm. The endosperm develops as a syncytium with the gradual organisation of domains along an anteroposterior axis defined by the position of the embryo at the anterior pole and by the attachment to the placenta at the posterior pole. We report that ontogenesis...

...Mikael Blom Sørensen; Ulrike Mayer; Wolfgang Lukowitz; Hélène Robert; Pierre Chambrier; Gerd Jürgens; Chris Somerville; Loic Lepiniec; Frédéric Berger Distinct forms of cytokinesis characterise specific phases of development in plants. In Arabidopsis , as in many other species, the endosperm...

...Philip W. Becraft; Kejian Li; Nrisingha Dey; Yvonne Asuncion-Crabb Mutants in the maize defective kernel1 ( dek1 ) gene are blocked in embryogenesis and the endosperm is chalky and lacks an aleurone layer. Here we show that intermediate alleles result in embryos that lack a shoot axis while weak...

... homozygous for abnormal leaf shape1 ( ale1 ) mutations were defective, resulting in excessive water loss and organ fusion in young plants. In ale1 embryos, the cuticle was rudimentary and remnants of the endosperm remained attached to developing embryos. Juvenile plants had a similar abnormal cuticle...

...Philip W. Becraft; Yvonne Asuncion-Crabb ABSTRACT A genetic analysis of maize aleurone development was conducted. Cell lineage was examined by simultaneously marking cells with C1 for anthocyanin pigmentation in the aleurone and wx1 for amylose synthesis in the starchy endosperm. The aleurone...

... distinctive phenotypes such as low weight and inhibition of mitosis in the endosperm, while extra paternal genomes result in reciprocal phenotypes such as high weight and endosperm overproliferation. DNA methylation is known to be an essential component of the parental imprinting mechanism in mammals...

... and tetraploid plants in either direction, resulting in double the normal dose of maternal or paternal genomes in the seed, produce viable seeds containing triploid embryos. However, development of the seed and in particular the endosperm is abnormal, with maternal and paternal genomic excess producing...

..., including fusion of nuclei, formation of ectopic internal walls, and disruptions to external wall patterning. In addition, ovules fertilized by tes pollen often abort, possibly because of excess paternal genomes in the endosperm. Thus tes mutants not only reveal a gene specific to male meiosis, but aid...

...Soon K. Hong; Hidemi Kitano; Hikaru Satoh; Yasuo Nagato ABSTRACT It is unclear how embryo size is genetically regulated in plants. Since cereals have a large persisting endosperm, it is expected that embryo size is affected by endosperm development. Nine single recessive mutations, four reduced...

... with the two central cell nuclei giving rise to the triploid endosperm. Since deviation from this nuclear ratio (2:1 maternal/paternal) in the endosperm can result in abortion, it has been suggested that the genomes of the sperm and/or central cell are differentially imprinted during sexual development...