Understanding plant nuclear structure – the spatial and dynamic organisation of the plant nucleus and the function and interactions of its components (e.g. RNA, proteins, nuclear envelope) – is vital in determining an integrated structural, physical and functional map of the genome. Along with the plant's genomic architecture – the organization of repetitive and single-copy DNA sequences along the chromosomes, and the nature, evolution, expression, recombination and segregation of the DNA sequences within the nucleus at various stages of cell division – it has important consequences for plant genetics.
Models of large scale genome organization are valuable in determining the function of different components of the genome. This fundamental work has applications in biodiversity, phylogenetic and evolution studies, and for plant breeding/crop improvement – e.g. understanding of the origin, diversity and evolution of agricultural species and improvement of these species using novel genetic resources. For example, breeding of drought-tolerant strains of food crops such as wheat, rye and barley using GM or transgenic genes.
Plant Nuclear Structure, Genome Architecture and Gene Regulation is based on significant progress made in the last five years in the knowledge and understanding of the organisation of the higher plant nucleus, and in particular in the relationship between nuclear organisation and the regulation of gene expression in a variety of contexts. Plant Nuclear Structure, Genome Architecture and Gene Regulation therefore begins with a consideration of the fundamentals underlying structural entities of the nucleus; the nuclear envelope and its associations; recent progress on the nucleoskeleton and plant lamina and the nuclear pore complexes. The role of the envelope in cell signalling is presented.
The second section of Plant Nuclear Structure, Genome Architecture and Gene Regulation then deals with nuclear structure and the nucleolus, and considers the role, structure and function of the nucleolus; chromatin packaging and the structure and organisation of the nucleus in meiosis including telomeres and anchorage of meiotic chromosomes.
In the third section, Nuclear structure, chromatin position and gene expression, topics include heterochromatin remodelling and nuclear architecture and its influence on gene expression; transposons; genomics and chromatin organization and chromosome structure, expression and interphase organization.
Finally, applications of the topic are considered including nuclear import and export of plant virus proteins and genomes and structural effects in transformation and DNA insertion.
1 Introduction: Mysteries, Molecules and Mechanisms
1.1 Darwin and Margulis revisited
1.2 Nuclei – general features
1.3 The plant nuclear genome
1.4 DNA inside, ribosomes outside
1.5 Concluding comments on the evolution of the nucleus
2. The Nuclear Envelope –Structure and Protein Interactions
Katja Graumann and David E. Evans
2.2 Organization and structure of the plant nuclear envelope
2.3 Proteins of the plant nuclear envelope
2.4 The plant nuclear envelope and the nucleoskeleton; attachments at the INM
2.5 The plant nuclear envelope and the cytoskeleton; attachments at the ONM
2.6 Targeting of proteins to the plant NE
2.7 Nuclear envelope protein dynamics in mitosis
2.8 The phragmoplast and cell plate and their relationship to the NE
2.9 The plant NE in meiosis
2.10 Lipid composition of the plant NE and its homeostasis
2.11 The role of plant NE components in stress responses
2.12 Concluding remarks
3 The Plant Nuclear Pore Complex – Nucleocytoplasmic Barrier and Beyond
Xiao Zhou, Joanna Boruc and Iris Meier
3.1 Nuclear pore complex structure
3.2 Physiological and developmental roles of plant nuclear pore components
3.3 The dynamics of the nuclear pore complex
4 Nucleoskeleton in Plants: The Functional Organization of Filaments in the Nucleus
Martin W. Goldberg
4.2 Intermediate filaments and the nucleoskeleton
4.3 Plants do not have intermediate filaments, but they may have functional equivalents
4.4 Plants can evolve different solutions to the same problem
4.5 Intermediate filaments first evolved in the nucleus
4.6 Plants require a rigid nuclear boundary
4.7 Is there a trans-nuclear envelope complex in plants that links the nucleoskeleton to the cytoskeleton?
4.8 Role of the nuclear lamina as part of the nucleoskeleton
4.9 Structural evidence for the nucleoskeleton
4.10 NuMA in plants
4.11 Matrix attachment regions (MARs) and the role of the nucleoskeleton in chromatin organization
4.12 Chromocentres and the plant nucleoskeleton
4.13 Long-coiled coil proteins in plants and their role in nuclear organization: candidates for plamins and nucleoskeletal proteins?
4.14 Actin and microtubules in the nucleus
5 Genomics and Chromatin Packaging
Eugenio Sanchez Moran
5.1 Chromatin components and structure in higher eukaryotes
5.2 Histones and nucleosome fibre
5.3 Linker histone and the higher order chromatin-order fibre
5.4 Chromatin loops and chromosome axis
5.5 Conclusions and future prospects
6 Heterochromatin Positioning and Nuclear Architecture
Emmanuel Vanrobays, Mélanie Thomas and Christophe Tatout
6.1 Heterochromatin structure
6.2 Heterochromatin organization
6.3 Functional significance of heterochromatin positioning
7 Telomeres in plant meiosis: their structure, dynamics and function
N.Y. Roberts, K. Osman, F.C.H. Franklin, M. Pradillo, J. Varas, J.L. Santos and S.J. Armstrong
7.2 The telomeres and associated proteins
7.3 The behaviour of the telomeres in meiosis
7.4 Telomere dynamics in Arabidopsis thaliana meiosis
7.5 How are the telomeres moved in meiotic prophase I?
7.6 Components of the nuclear envelope
7.7 Components of the plant nuclear envelope
7.8 Conclusions and future prospects
8 The Nuclear Pore Complex in Symbiosis and Pathogen Defence
Andreas Binder and Martin Parniske
8.2 The nuclear pore and plant-microbe symbiosis
8.3 The nuclear pore and plant defence
8.4 Specificity, redundancy andgeneral functions of plant nucleoporins
8.5 Challenges and conclusion
David E. Evans and Katja Graumann are based at the Department of Biological and Medical Sciences, Oxford Brookes University, UK. John A. Bryant is based at the Biosciences Department at the University of Exeter, UK.