Organellar Genomes in Barley
Similar to other higher plants, barley (Hordeum vulgare) contains the following three cell organelles that possess their own genomes: nucleus, mitochondrion, and chloroplast. In this chapter, the genome structures, genetic content, and functions of two cytoplasmic organelles, i.e., mitochondrion and chloroplast, in barley are discussed. The barley mitochondrial genome (mt genome) is 525,599 bp in size, which is 73 kb larger than that of wheat, and the gene content is well conserved among grass species; notably, the contents of intact protein-coding genes in barley are the same as those in wheat. However, the mt genome structure is markedly different among grass species, and rearrangements and fragmentations of homologous regions prevent the reconfiguration of evolutionary processes, even in the same Triticeae lineage, which includes barley and wheat. However, the genome structure and gene content of chloroplast genome (cp genome) are highly conserved among grass species. The cp genome in barley is 136,462 bp in size, and the quadripartite structures that are common in the cp genome of higher plants are conserved. Most sequences are collinear between wheat and barley, and the gene content and gene order in barley are identical to those in wheat. Chloroplasts and mitochondria are essential organelles, and the genes encoded in both organellar genomes are indispensable for plant cell survival. Several genetic interactions among the cell organelles, nucleus, mitochondrion, and chloroplast occur within a cell. In this chapter, these genetic interactions and outcomes, including cytoplasmic male sterility (CMS) and chloroplast dysfunction, are reviewed. These phenomena are interesting and important for the understanding of the physiological function of both cytoplasmic organelles and their potential use in plant breeding. We have only recently begun to understand these genetic interactions due to the publication of the complete genomes of the nucleus, mitochondrion, and chloroplast in barley.
KeywordsOrganelles Mitochondria Chloroplast Genome structure Interactions
The author would like to thank Hiroshi Hisano (IPSR, Okayama University) for the critical reading and valuable suggestions.
- Greiner S (2012) Plastome mutants of higher plants. In: Bock R, Knoop V (eds) Genomics of chloroplasts and mitochondria, advances in photosynthesis and respiration, vol 35. Springer, The Netherlands, pp 237–266Google Scholar
- Hagemann R, Scholz F (1962) Ein Fall Gen-induzierter Mutationen des Plasmotyps bei Gerste. Der Züchter 32:50–59Google Scholar
- Handa H (2003) The complete nucleotide sequence and RNA editing content of the mitochondrial genome of rapeseed (Brassica napus L.): comparative analysis of the mitochondrial genomes of rapeseed and Arabidopsis thaliana. Nucl Acids Res 31:5907–5916Google Scholar
- Hiratsuka J, Shimada H, Whittier R, Ishibashi T, Sakamoto M, Mori M, Kondo C, Honji Y, Sun CR, Meng BY, Li YQ, Kanno A, Nishizawa Y, Hirai A, Shinozaki K, Sugiura M (1989) The complete sequence of the rice (Oryza sativa) chloroplast genome: intermolecular recombination between distinct tRNA genes accounts for a major plastid DNA inversion during the evolution of the cereals. Mol Gen Genet 217:185–194CrossRefPubMedGoogle Scholar
- Jensen PE, Leister D (2014) Chloroplast evolution, structure and functions. F1000Prime Rep 6:40Google Scholar
- Notsu Y, Masood S, Nishikawa T, Kubo N, Akiduki G, Nakazono M, Hirai A, Kadowaki K (2002) The complete sequence of the rice (Oryza sativa L.) mitochondrial genome: frequent DNA sequence acquisition and loss during the evolution of flowering plants. Mol Genet Genomics 268:434–445CrossRefPubMedGoogle Scholar
- Ogihara Y, Isono K, Kojima T, Endo A, Hanaoka M, Shiina T, Terachi T, Utsugi S, Murata M, Mori N, Takumi S, Ikeo K, Gojobori T, Murai R, Murai K, Matsuoka Y, Ohnishi Y, Tajiri H, Tsunewaki K (2002) Structural features of a wheat plastome as revealed by complete sequencing of chloroplast DNA. Mol Genet Genomics 266:740–746CrossRefPubMedGoogle Scholar
- Ogihara Y, Yamazaki Y, Murai K, Kanno A, Terachi T, Shiina T, Miyashita N, Nasuda S, Nakamura C, Mori N, Takumi S, Murata M, Futo S, Tsunewaki K (2005) Structural dynamics of cereal mitochondrial genomes as revealed by complete nucleotide sequencing of the wheat mitochondrial genome. Nucleic Acids Res 33:6235–6250CrossRefPubMedPubMedCentralGoogle Scholar
- Prina AR, Landau A, Colombo N, Jaureguialzo M, Arias MC, Rios RD, Pacheco MG (2009) Genetically unstable mutants as novel sources of genetic variability: the chloroplast mutator genotype in barley as a tool for exploring the plastid genome. In: Shu QY (ed) Induced plant mutations in the genomics era. FAO, Rome, pp 255–256Google Scholar
- Saski C, Lee SB, Fjellheim S, Guda C, Jansen RK, Luo H, Tomkins J, Rognli OA, Daniell H, Clarke JL (2007) Complete chloroplast genome sequences of Hordeum vulgare, Sorghum bicolor and Agrostis stolonifera, and comparative analyses with other grass genomes. Theor Appl Genet 115:571–590CrossRefPubMedPubMedCentralGoogle Scholar