Regulation of chloroplast number and DNA synthesis in higher plants. Final report, August 1995--August 1996

The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focused on obtaining a detailed description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The research focused on the isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell

Regulation of chloroplast number and DNA synthesis in higher plants. Final report

The long term objective of this research is to understand the process of chloroplast development and its coordination with leaf development in higher plants. This is important because the photosynthetic capacity of plants is directly related to leaf and chloroplast development. This research focuses on obtaining a detailing description of leaf development and the early steps in chloroplast development including activation of plastid DNA synthesis, changes in plastid DNA copy number, activation of chloroplast transcription and increases in plastid number per cell. The grant will also begin analysis of specific biochemical mechanisms by isolation of the plastid DNA polymerase, and identification of genetic mutants which are altered in their accumulation of plastid DNA and plastid number per cell

Flowering Time

Adaptation genes have a major role to play in the response of plants to environmental changes. Flowering time is a key adaptive trait, responding to environmental and endogenous signals that ensure reproductive growth and devel- opment occurs under favorable environmental conditions. Under a climate change scenario, temperature and water conditions are forecast to change and/or fluctuate, while photoperiods will remain constant at any given latitude. By assessing the current knowledge of the flowering-time pathways in both model (Arabidopsis thaliana) and key cereal (rice, barley, wheat, maize), temperate forage and biofuel grasses (perennial ryegrass, Miscanthus, sugarcane), root (sugar beet), and tree (poplar) crop species, it is possible to define key breeding targets for promoting adaptation and yield stability under future climatic conditions. In Arabidopsis, there are four pathways controlling flowering time, and the genetic and/or epigenetic control of many of the steps in these pathways has been well characterized. Despite A.R. Bentley • I.J. Mackay • E. Mutasa-Go ¨ttgens • J. Cockram (*) The John Bingham Laboratory, NIAB, Huntingdon Road, Cambridge CB3 0LE, UK e-mail: [email protected] E.F. Jensen • I.P. Armstead • C. Hayes • D. Thorogood • A. Lovatt Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth SY23 3EB, UK H. Ho ¨nicka • M. Fladung Johann Heinrich von Thu ¨nen Institute, Institute of Forest Genetics, Sieker Landstr. 2, 22927 Grosshansdorf, Germany K. Hori • M. Yano National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan J.E. Mullet Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA R. Morris • N. Pullen Computational and Systems Biology Department, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK C. Kole (ed.), Genomics and Breeding for Climate-Resilient Crops, Vol. 2, DOI 10.1007/978-3-642-37048-9_1, © Springer-Verlag Berlin Heidelberg 2013 1 this, even in this model species, there is little published information on the molecu- lar basis of adaptation to the environment. In contrast, in crop and tree species, flowering time has been continually selected, either directly or indirectly as breeders and growers have selected the material that best suits a particular location. Understanding the genetic basis of this adaptive selection is now being facilitated via cloning of major genes, the mapping of QTL, and the use of marker-assisted breeding for specific flowering targets. In crop species where the genetic basis of flowering is not well understood (i.e., in the emerging biofuel grass, Miscanthus), such work is in its infancy. In cases where the genetic basis is well established, however, there are still grounds for important discovery, via new and emerging methods for mapping and selecting for flowering-time traits (i.e., QTL mapping in MAGIC populations, RABID selection), as well as methods for creating new genetic combinations with potentially novel flowering-time phenotypes (i.e., via targeted mutagenesis). In the future it is likely that computational modeling approaches which incorporate gene networks and the range of phenological response to measurable environmental conditions will play a central role in predicting the resilience of crop and tree species under climate change scenarios.Peer reviewe