Location of Repository

The identification and characterisation of key genes involved in somatic embryogenesis in wheat (Triticum, aestivum L.)

By Ben Michael Minogue


One of the most remarkable aspects of plants cells is that on application of the plant hormone auxin, they possess the unique ability to de-differentiate and return to embryonic development, via a process known as `somatic embryogenesis' (SE). On removal of auxin these totipotent cells are then capable of re-differentiating and regenerating into full adult plants. Although well characterised physiologically, the molecular mechanisms that regulate this important biological process are still very poorly understood. The research aim of this project was to improve our understanding of SE, by designing a series of cDNA microarray experiments to identify the genetic components responsible for the de-differentiation of somatic cells\ud to an embryonic state and the initiation, development and differentiation of somatic embryos towards adult structures. To achieve this aim, suitable embryogenic and\ud non-embryogenic systems were established and used for subtractive microarray analysis that has identified 701 differentially expressed genes that are specifically\ud related to SE in wheat. Following bioinformatic and expression analysis, 57 of these genes were short listed and further characterised by in situ hybridisation (ISH) to\ud provide further information of their temporal and spatial patterns of expression. A small subset of genes that demonstrated interesting patterns of expression, were\ud further characterised and functionally analysed via RNAi silencing studies. Here it is demonstrated that all of the genes tested for RNAi silencing results in a reduction of\ud the transformation and regeneration efficiencies. Furthermore the targeted silencing of several of these novel genes was shown to have an observable phenotypic effect on the development of somatic embryos and regeneration in wheat. Of particular interest is a wheat gene related to the rice embryo specific protein OSE 731, which appears to play an essential role in the transition of somatic embryos into differentiating adult structures. The silencing of this gene resulted in the continuous proliferation of somatic embryos (SEs) and arrested the development of these SEs into differentiated adult structures

Publisher: Faculty of Biological Sciences (Leeds)
Year: 2007
OAI identifier: oai:etheses.whiterose.ac.uk:354

Suggested articles



  1. (1978). 2,4-Dichlorophenoxyacetic acid-enhanced phosphorylation of soybean nuclear proteins. " doi
  2. (2000). A DEFICIENS homolog from the dioecious tree black cottonwood is expressed in female and male floral meristems of the two-whorled, unisexual flowers. " doi
  3. (1999). A gene family encoding glutathione peroxidase homologues in Hordeum vulgare (barley). " doi
  4. (1996). A member of the KNOTTED class of homeodomain proteins encoded by the STM gene ofArabidopsis. " doi
  5. (2001). A method for highthroughput in situ analysis of mRNA in plants. "
  6. (2004). a microRNA as a translation repressor of APETALA in Arabidopsis flower development. "
  7. (1990). A novel mammalian protein kinase gene (mak) is highly expressed in testicular germ cells at and after meiosis. "
  8. (1962). A revised medium for rapid growth and bioassays with tobacco tissue cultures. " doi
  9. (1989). A set of surface glycoproteins forms an early marker of cell position, but not cell type, in the root apical meristem of Daucus carota L. "
  10. (1993). A simple and efficient method for isolating RNA from pine trees. " doi
  11. (1999). A species of small antisense RNA in post-transcriptional gene silencing in plants. " doi
  12. (2004). A WD40 repeat protein regulates fungal cell differentiation and can be replaced functionally by the mammalian homologue striatin. " Eukaryotic Cell 3(l): doi
  13. (2000). ABFs, a family of ABA-responsive element binding factors. " doi
  14. (1996). Activation of floral meristem identity genes in Arabidopsis. " doi
  15. (1993). Active cdc2 genes and cell cycle phase specific cdc2-related kinase complexes in hormone stimulated alfalfa cells. " doi
  16. (1964). Adventive embryony in tissue cultures of the wild carrot, Daucus carota. " doi
  17. (2004). An approach to genomewide screens of expressed small interfering RNAs in mammalian cells. " doi
  18. (2000). An RNA-directed nuclease mediates post transcriptional gene silcening in Drosophila cell. "
  19. (1997). Anti-sense expression of the peptide transport gene, AtPTR2B, delays flowering and arrests seed development in transgenic Arabidopsis plants. " doi
  20. (2001). Apical-basal pattern formation in Arabidopsis embryogenesis. " doi
  21. (1993). Apical-basal pattern formation in the Arabidopsis embryo: studies on the role of the gnom gene. "
  22. (1996). Arabidopsis AUX1 gene: a permease-like regulator of root gravitropism. " doi
  23. (1998). Arabidopsis LEAFY COTYLEDON] is sufficient to induce embryo development in vegetative cells. " doi
  24. (1995). Arabinogalactan-protein epitopes in somatic embryogenesis of Daucus carota L. " doi
  25. (1997). ARFI, a transcription factor that binds to auxin response elements. " doi
  26. (1996). Arteca doi
  27. (1998). AT-hook motifs identified in a wide variety of DNA-binding proteins. " doi
  28. (2002). AtOPT3, a member of the oligopeptide transporter family, is essential for embryo development in Arabidopsis. " doi
  29. (1998). AtPIN2 defines a locus of Arabidopsis for root gravitropism control. " doi
  30. (2002). AtPIN4 Mediates Sink-Driven Auxin Gradients and Root Patterning in Arabidopsis. " doi
  31. (1997). Aux/IAA proteins repress expression of reporter genes containing natural and highly active synthetic auxin response elements. " doi
  32. (2001). Auxin transport inhibitors block PIN1 cycling and vesicle trafficking. " doi
  33. (1998). Auxin-induced developmental patterns in Brassicajuncea embryos. "
  34. (1995). Biochemical and molecular characterization of a barley seed [IMAGE]-glucosidase. " doi
  35. (1988). Calcium dependent protein kinase from alfalfa (Medicago varia): partial purification and autophosphorylation. " doi
  36. (1991). cDNA cloning of a novel cdc2+/DCD28-related protein kinase from rice. " doi
  37. (2002). Cell cycle regulated gene expression in Arabidopsis. " doi
  38. (2003). Cestrum yellow leaf curling virus (CmYLCV) promoter: a new strong constitutive promoter for heterologous gene expression in a wide variety of crops. " doi
  39. (2000). Characterization of a Mak subgroup Cdc2-like protein kinase from sugar beet (Beta vulgaris L. ). " doi
  40. (2001). Characterization of plant proliferating cell nuclear antigen (PCNA) and flap endonuclease-1 (FEN-1), and their distribution in mitotic and meiotic cell cycles. " doi
  41. (1993). CLAVATA1, a regulator of meristem and flower development in Arabidopsis. "
  42. (1995). CLAVATA3 is a specific regulator of shoot and floral meristem development affecting the same processes as CLAVATAI. "
  43. Cloning of new members of heat shock protein HSP101 gene family in wheat (Triticum aestivum (L. ) Moench) inducible by heat, dehydration, and ABA!. " doi
  44. (2000). Cloning, mapping and expression analysis of barley MADS-box genes. " doi
  45. (2003). Comparative analysis of SET domain proteins in Maize and Arabidopsis reveals multiple duplications preceding the divergence of monocots and dicots. " doi
  46. (1991). Complementation of a yeast cell cycle mutant by an alfalfa cDNA encoding a protein kinase homologous to p34cdc2. " doi
  47. (1998). Construction and screening of normalized cDNA libraries.
  48. (2003). Control of leaf morphogenesis by microRNAs. " doi
  49. (1999). Coordinated polar localization of auxin efflux carrier PINT by GNOMARF GEF. "
  50. (2000). Crkl, a novel Cdc2-related protein kinase, Is required for hyphal development and virulence in candida albicans. " Molecular and Cellular Biology doi
  51. (1999). Cullin-3 targets cyclin E for ubiquitination and controls S phase in mammalian cells. " doi
  52. (2001). Current status of wheat transformation. "
  53. (1996). Cytokinesis in the Arabidopsis embryo involves the syntaxin-related KNOLLE gene product. " doi
  54. (2002). De Vries doi
  55. (2002). Design issues for cDNA microarray experiments. "
  56. (1991). Developmentally regulated epitopes of the cell surface Arabinogalactan proteins and their relation to root tissue pattern formation. " doi
  57. (2001). Dicer functions in RNA interference and in synthesis of small RNA involved in developmental timing in C. doi
  58. (1994). Disruption of hydrogen bonding between wall polymers by proteins that induce plant wall extension. " doi
  59. (2003). Distinct mechanisms determine transposon inheritance and methylation via small interfering RNA and histone modification. " doi
  60. (1989). DNA methylation and embryogenic competence in leaves and callus of Napiergrass (Pennisetum purpureum Schum). " doi
  61. (1997). E7TIN patterns the Arabidopsis floral meristem and reproductive organs. "
  62. (1997). Each sequence was aligned with Clustalx
  63. (1994). Early auxin-induced genes encode short-lived nuclear proteins. " doi
  64. (1987). Effect of auxin on the mitotic cell cycle in cultured leaf segments at different stages of development in wheat. " doi
  65. (2004). Effect of herbicidal application of 2,4-dichlorophenoxyacetic acid in Arabidopsis. " Functional and Integrative Genomics. doi
  66. (1986). Effect of phytohormones on replicative and postreplicative methylation of nuclear DNA in the S phase of the cell cycel of cells of the first leaf of etiolated wheat seedlings. "
  67. (1990). Effects of Auxin and Abscisic Acid on Cytosolic Calcium and pH in Plant Cells. " doi
  68. (2003). Efflux-dependent auxin gradients establish the apical-basal axis of Arabidopsis. " doi
  69. (1994). EMB30 is essential for normal cell division, cell expansion, and cell adhesion in Arabidopsis and encodes a protein that has similarity to Sec7. " doi
  70. (1994). Embryonic pattern formation in flowering plants. " doi
  71. (1981). Embryonic proteins in somatic embryos of carrot. " doi
  72. (2003). Embryonic stem cell-specific MicroRNAs. " doi
  73. (1994). Establishing the body plan of the Arabidopsis embryo. " doi
  74. (2001). Evidence for an important role of WRKY DNA binding proteins in the regulation of NPRI gene expression. " doi
  75. (1999). Expansins are conserved in conifers and expressed in response to exogenous auxin. " doi
  76. (2004). Expression dynamics of WOX genes mark cell fate decisions during early embryonic patterning in Arabidopsis thaliana. " doi
  77. (2002). Expression profiling of reciprocal maize hybrids divergent for cold germination and desiccation tolerance. " doi
  78. (2003). Expression profiling reveals off-target gene regulation by RNAi. " doi
  79. FACKEL is a sterol C-14 reductase required for organized cell division and expansion in Arabidopsis embryogenesis. "
  80. (1984). Fertilization increases the polyphosphoinositide content of sea urchin eggs. " doi
  81. (1993). Formation of the shoot apical meristem in Arabidopsis thaliana: an analysis of development in the wild type and in the shoot meristemless mutant. " doi
  82. (1997). Fundamental concepts in the embryogenesis of dicotyledons: A morphological interpretation of embryo mutants. " doi
  83. (2004). Funneling auxin action: specificity in signal transduction. " doi
  84. (1999). GEM microarray reproducibility study. " Incyte technical survey.
  85. (1988). Gene expression programs in embryogenic and non-embryogenic carrot cultures. " doi
  86. (2000). Gene expression: Total silencing by intron-spliced hairpin RNAs. "
  87. (2004). Gene regulation: ancient microRNA target sequences in plant. " doi
  88. (2001). Gene silencing as an adaptive defence against viruses. " doi
  89. (2004). Genetic and functional diversification of small RNA pathways in plants. " doi
  90. (2000). Genomics, gene expression and DNA arrays. "
  91. (1996). Gibberellin-repressible gene expression in the barley aleurone layer. " doi
  92. (1997). Group I allergens of grass pollen as cell wall-loosening agents. " doi
  93. (1958). Growth and organized development of cultured cells: II. Organization in cultures grown from freely suspended cells. " doi
  94. (2004). gurke and pasticcino3 mutants affected in embryo development are impaired in acetyl-CoA carboxylase. " doi
  95. (1987). Heat-shock proteins and development. " doi
  96. (1991). Highly conserved structure of proliferating cell nuclear antigen (DNA polymerase delta auxiliary protein) gene in plants. " doi
  97. (1928). Hosts and symptoms of ring spot, a virus disease of plants. "
  98. (1997). HsMCM6: a new member of the human MCM/PI family encodes a protein homologous to fission yeast MisS. " Genes to Cells doi
  99. (2000). Identification and analysis of proteins that interact with the Avenafatua homologue of the maize transcription factor VIVIPAROUS 1. " doi
  100. (1998). Identification of a dual- specificity protein phosphatase that inactivates MAP kinase in Arabidopsis. " doi
  101. (1996). Identification of a meristem L1 layer-specific gene in Arabidopsis that is expressed during embryonic pattern formation and defines a new class of homeobox genes. " doi
  102. (1992). Identification of a polyphosphoinositidebinding sequence in an actin monomer-binding domain of gelsolin. "
  103. (1999). Identification of an SCF ubiquitin-ligase complex required for auxin response in Arabidopsis thaliana. " doi
  104. (1990). Identification of callus types for long term maintenance and regeneration from commercial cultivars of wheat (Triticum aestivum L. ). " doi
  105. (2002). Identification of highly transformable wheat genotypes for mass production of fertile transgenic plants. " doi
  106. (1997). indicates the number of nucleotide replacements per site.
  107. (1997). Induction of leaf primordia by the cell wall protein expansin. " doi
  108. (1998). Influence of endogenous GM I ganglioside on TrkB activity in cultured neurons. " doi
  109. (2001). Initiating DNA synthesis: from recruiting to activating the MCM complex. "
  110. (1994). Interaction of a protein phosphatase with an Arabidopsis serine-threonine receptor kinase. " doi
  111. (1992). Interactions between doublestranded RNA regulators and the protein kinase DAI.. "
  112. (2001). Intercellular movement of the putative transcription factor SHR in root patterning. " doi
  113. (1997). Isolation of cDNA clones for genes that are specifically expressed in the rice embryo. "
  114. (2002). Isolation of two somatic embryogenesis-related genes from orchardgrass (Dactylis glomerata). " doi
  115. (2003). Laser-capture microdissection, a tool for the global analysis of gene expression in specific plant cell types: Identification of genes expressed differentially in epidermal cells or vascular tissues of maize. " doi
  116. (2001). LEAFY COTYLEDON2 encodes a B3 domain transcription factor that induces embryo development. " doi
  117. (1994). LEAFYCOTYLEDONI Is an essential regulator of late embryogenesis and cotyledon identity in Arabidopsis. " doi
  118. (2003). Local, efflux-dependent auxin gradients as a common module for plant organ formation. " doi
  119. (1996). Maize Chromosomal HMGc. Two closely related structure-specific DNA-binding proteins specify a second type of plant high mobility group box protein. " doi
  120. (1992). Maize polyubiquitin genes: structure, thermal perturbation of expression and transcript splicing, and promoter activity following transfer to protoplasts by electroporation. " doi
  121. (2004). Mechanisms of pattern formation in plant embryogenesis. " doi
  122. (2004). MicroRNAs: genomics, biogenesis, mechanism and function. "
  123. (2002). miRNPs: a novel class of ribonucleoproteins containing numerous microRNAs. " doi
  124. (1999). Mitogen-activated protein kinases: Specific messages from ubiquitous messengers. "
  125. (1980). Mode of action of 2,4-D and zeatin on somatic embryogenesis in a carrot cell suspension culture. " doi
  126. (2000). Molecular and Biochemical Evidence for the Involvement of Calcium/Calmodulin in Auxin Action. " doi
  127. (1999). Molecular cloning and characterisation of a maize cDNA for a homologue of the large subunit of the eukaryotic initiation factor 3 (eIF3). " Molecular and General Genetics 261(4-5): doi
  128. (1998). Molecular cloning in Arabidopsis thaliana of a new protein phosphatase 2C (PP2C) with homology to ABII and ABI2. "
  129. (1958). Morphogenese und ihre kontrolle an gewebekulturen aus carotten. " doi
  130. (2000). New members of a cold-responsive doi
  131. (2001). Novel auxin transport inhibitors phenocopy the auxin influx carrier mutation aux1. " doi
  132. (2000). Osmotic stress induces rapid activation of a salicylic acid-induced protein kinase and a homolog of protein kinase ASK1 in tobacco cells. " doi
  133. (1999). PICKLE is a CHD3 chromatinremodeling factor that regulates the transition from embryonic to vegetative development in 196 Arabidopsis. " doi
  134. (1989). Plant cell wall architecture. " doi
  135. (1992). Ploidy reduction and genome segregation in cultured carrot cell lines . 11. Somatic meiosis. " doi
  136. (2001). Post-transcriptional gene silencing by double-stranded RNA. " doi
  137. (1998). Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans. " doi
  138. (2002). Prediction of plant microRNA targets. " doi
  139. (2004). Protein displacement by DExH/D "RNA Helicases" without duplex unwinding. " doi
  140. (1993). Rapid production of multiple independent lines of fertile transgenic wheat (Triticum aestivum). "
  141. (1997). Refined structure of villin 14T and a detailed comparison with other actin-severing domains. " doi
  142. (2003). Regulation of phyllotaxis by polar auxin transport. " doi
  143. Regulation of Polar Auxin Transport by AtPINI in Arabidopsis Vascular Tissue. " doi
  144. (2004). Regulation of the dual specificity protein phosphatase, DsPTPI, through interactions with Calmodulin. "
  145. (1993). Reismeier
  146. Release of active cytokinin by a beta-glucosidase localized to the maize root meristem. " doi
  147. (1991). Requirement of the Auxin Polar Transport System in Early Stages of Arabidopsis Floral Bud Formation. " doi
  148. (2005). Rice plant development: from zygote to spikelet. "
  149. (2004). RNA silencing in plants. " doi
  150. (2004). RNAimediated targeting of heterochromatin by the RITS complex. "
  151. (2004). Role of transposable elements in heterochromatin and epigenetic control. " doi
  152. (1998). Role of WUSCHEL in regulating stem cell fate in the Arabidopsis shoot meristem. " doi
  153. (1993). Root development in Arabidopsis: four mutants with dramatically altered root morphogenesis. "
  154. (2003). Rootspecific CLE19 ovexpression and the soll/2 supressors implicate a CLV-like pathway in the control of Arabidopsis root meristem maintenance. " Current Biology. doi
  155. (2003). SCARECROW is involved in positioning the stem cell niche in the Arabidopsis root meristem. " doi
  156. (1988). Sequence heterogeneity and differential expression of the alpha-Amyl gene family in wheat. " doi
  157. (1997). Short range control of cell differentiation in the Arabidopsis root meristem. " doi
  158. (1999). Signalling of cell fate decisions by CLAVATA3 in Arabidopsis shoot meristems. " doi
  159. (2001). Sites and homeostatic control of auxin biosynthesis in Arabidopsis during vegetative growth. " doi
  160. (1993). Somatic embryogenesis: A model for early development in higher plants. " Plant Ce115: doi
  161. (1994). Soybean GH3 promoter contains multiple auxin-inducible elements. " doi
  162. (2001). Spectrin and ankyrin-based pathways: Metazoan inventions for integrating cells Into tissues. "
  163. Sterols regulate development and gene expression in Arabidopsis. " doi
  164. (1979). Structural requirements of doublestranded RNA for the activation of 2'-5'-oligo(A) polymerase and protein kinase of interferon-treated HeLa cells. ." doi
  165. (1999). Sucrose and cytokinin modulation of WPK4, a gene encoding a SNF1-related protein kinase from wheat. " doi
  166. (2000). The 21-nucleotide let-7 RNA regulates developmental timing in Caenorhabditis elegans. " doi
  167. (1990). The A. T-DNA-binding domain of mammalian high mobility group I chromosomal proteins. A novel peptide motif for recognizing DNA structure. "
  168. (2002). The activated glucocorticoid receptor modulates presumptive autoregulation of ribosomal protein S6 protein kinase, p70 S6K. " doi
  169. (1999). The Arabidopsis CLAVATA2 gene encodes a receptor-like protein required for the stability of the CLAVATAI receptor-like kinase. " doi
  170. (1998). The Arabidopsis gene MONOPTEROS encodes a transcription factor mediating embryo axis formation and vascular development. " doi
  171. (2003). The Arabidopsis GNOM ARF-GEF Mediates Endosomal Recycling, Auxin Transport, and Auxin-Dependent Plant Growth. " doi
  172. (1997). The CLAVATAI gene encodes a putatuve receptor kinase that controls shoot and floral mersitem size in Arabidopsis. " doi
  173. (2002). The CRKI receptor-like kinase gene of tobacco is negatively regulated by cytokinin. "
  174. (2001). The cytokinesis gene KEULE encodes a Secl protein that binds the syntaxin KNOLLE. " doi
  175. (2005). The elongata mutants identify a functional Elongator complex in plants with a role in cell proliferation during organ growth. " doi
  176. (2005). The F-box protein TIRI is an auxin receptor. " doi
  177. (2004). The functions of animal microRNAs. doi
  178. (2002). The genetics of RNA silencing. " doi
  179. (1999). The GRAS gene family in Arabidopsis: sequence characterization and basic expression analysis of the SCARECROW-LIKE genes. " doi
  180. (2004). The GURKE Gene Encoding an Acetyl-CoA Carboxylase is Required for Partitioning the Embryo Apex into Three Subregions in Arabidopsis. " doi
  181. (1996). The GURKE gene is required for normal organization of the apical region in the Arabidopsis embryo. " doi
  182. (1999). The lin-4 regulatory RNA controls developmental timing in caenorhabditis elegans by blocking LIN-14 protein synthesis after the initiation of translation. " doi
  183. (2001). The maize MADS box gene ZmMADS3 affects node number and spikelet development and Is co-expressed with ZmMADSI during flower development, in egg cells, and early embryogenesis. " doi
  184. (1999). The maize rough sheath2 gene and leaf development programs in monocot and dicot plants. " doi
  185. (1993). The role of the monopteros gene in organising the basal body region of the Arabidopsis embryo. " doi
  186. (1996). The SCARECROW gene regulates an asymmetric cell division that is essential for generating the radial organization of the Arabidopsis root. " doi
  187. (2000). The secretory carrier membrane protein family: Structure and membrane topology. " doi
  188. (2000). The stem cell population of Arabidopsis shoot meristems is maintained by a regulatory loop between the CLI VA TA and WUSCHEL genes. " doi
  189. (1993). The Tousled gene in A. thaliana encodes a protein kinase homolog that is required for leaf and flower development. " doi
  190. (1999). The wheat peptidyl prolyl cis-transisomerase FKBP77 is heat induced and developmentally regulated. " doi
  191. (1996). The WUSCHEL gene is required for shoot and floral meristem integrity in Arabidopsis. " doi
  192. (2002). The WUSCHEL gene promotes vegetative-toembryonic transition in Arabidopsis. " doi
  193. (1997). TOUSLED participates in apical tissue formation during gynoecium development in Arabidopsis. " doi
  194. (2003). Tousled-like kinase functions with the chromatin assembly pathway regulating nuclear divisions. " doi
  195. (1989). Transcription, organization, and sequence of an auxin-regulated gene cluster in soybean. " doi
  196. (1997). TSOI functions in cell division during Arabidopsis flower development. "
  197. (2000). TSOI is a novel protein that modulates cytokinesis and cell expansion in Arabidopsis. "
  198. (1992). Two endogenous proteins that induce cell wall expansion in plants. " Plant Ce114: doi
  199. (1987). Unusual patterns of embryogenesis in the domesticated carrot: developmental effects of exogenous auxins and auxin transport inhibitors. " doi
  200. (2002). van Lookeren Campagne doi
  201. (1997). ZmMADS18lemb11AJ292960 Phylogenetic tree for TaESTI701961640IMADS9 produced by BLAST analysis in EMBL nonredundant database. Each sequence was aligned with Clustalx (Thompson et al.,
  202. (1999). ZmOCLI, an HDGL2 family homeobox gene, is expressed in the outer cell layer throughout maize development. "
  203. (1997). Zygotic embryogenesis versus somatic embryogenesis. " doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.