Somatic Embryogenesis - Apical Meristems and Embryo Conversion

  • Yeung, Edward C. (Department of Biological Sciences, University of Calgary) ;
  • Stasolla, Claudio (Department of Biological Sciences, University of Calgary)
  • Published : 2000.07.01

Abstract

A large amount of information is currently available for somatic embryogenesis of plants. However, one common problem related to somatic embryos is that the conversion rate can be low for some species. Apical meristems are responsible for post-embryonic growth of the embryo. The low percentage observed is most likely a result of poor apical meristem development or defects in the meristem organization during somatic embryogenesis. In flowering plants, apical meristems are well developed by the late heart stage of zygotic embryo development. In conifers, such as white spruce, apical meristems are formed at the pre-cotyledon stage. Thus, apical meristem development occurs very early, prior to the maturation stage of embryo development. Once formed, meristems are stably determined. In the somatic embryo, as exemplified by white spruce, since embryo development is not synchronous, tissue differentiation including apical meristem formation occurs throughout the“maturation”stage. Different apical meristem organizations can be found among different individuals within a population. In contrast to their zygotic counterparts, the apical meristems appear not to be stably determined as their organization, as the shoot apical meristem especially, can be easily modified or disrupted. Precocious germination seldom results in functional plantlets. All these observations suggest that the conditions for somatic embryo maturation have not been optimized or are not suitable for meristem formation and development. The following strategies could improve meristem development and hence conversion: 1. Simulate in ouuio conditions to promote meristem development prior to the“maturation”treatment.2. Prevent deterioration of apical meristem organization during somatic embryo maturation.3. Promote further meristem development during embryo germination.

Keywords

References

  1. Amer. J. Bot. v.34 Embryogeny and the development of the apical meristems in Pesudotsuga. Ⅲ. Development of the apical meristems Allen GS
  2. Plant Tissue and Cell Culture Organization events during somatic embryogenesis Ammirato PV;Green CE(ed.);Somers CA(ed.);Hackett WP(ed.) Biesboer DD(ed.)
  3. Plant Cell Tiss. Org. Cult v.35 Somatic embryogenesis and synthetic seeds of conifers Attree SM;Fowke LC
  4. Ann. Bot. v.68 Enhanced maturation and desiccation tolerance of white spruce【Picea glauca (Moench) Voss】 somatic embryos: effects of a non-plasmolysing water stress and abscisic acid Attree SM;Moore D;Sawhney VK;Fowke LC
  5. Development v.119 Formation of the shoot apical meristem of Arabidoposis thaliana: an analysis of development in the wild type and in the shoot meristemless mutant Barton MK;Poethig RS
  6. Science v.205 Determination of the pore size of cell walls of living plant cells Carpita N;Sabularse D;Montezinos D;Delmer D
  7. Development v.122 The CLAVATA and SHOOT MERISTEMLESS loci competitively regulate meristem activity in Arabidopsis Clark SE;Jacobsen SE;Levin JZ;Meyerowitz EM
  8. Annu. Rev. Plant Physiol. Plant Mol. Biol. v.48 Genetics of angiosperm shoot apical meristem Evans MS;Barton MK
  9. Plant Sci. v.128 Changes in endogenous ABA levels in developing somatic embryos of Norway spruce (Picea abies (L) Karst.) in relation to maturation medium desiccation and germination Find JI
  10. Bot. Rev. v.37 The shoot apex in seed plants Gifford EM Jr.;Corson GE Jr.
  11. Amer. J. Bot. v.59 The shoot apical ontogeny of the picea abies seedling. Ⅰ. Anatomy, apical dome diameter, and plastochron duration Gregory RA;Romberger JA
  12. Somatic Embryogenesis in Woody Plants v.1 Somatic embryogenesis in conifers Gupta PK;Grob JA;Mohan Jain S(ed.);Gupta P(ed.);Newton R(ed.)
  13. Somatic Embryogenesis in Woody Plants v.4 Somatic embryo germination and desication tolerance in conifers Hay E I;Charest PJ;Mohan Jain S(ed.);Gupta P(ed.);Newton R(ed.)
  14. Plant Cell Rep v.17 Induction fo microspore-derived embryos of Brassica napus L. with polyethylene glycol (PEG) as osmoticum in a low sucrose medium Ilic-Grubor K;Attree SM;Fowke LC
  15. Ann. Bot. v.82 Comparative morphological study of zygotiic and microspore-derived embryos of Brassica napus L. as revealed by scanning electron microscopy Ilic-Grubor K;Attree SM;Fowke LC
  16. Somatic Embryogenesis in Woody Plants v.1-5 Jain SM;Gupta P;Newton R(eds)
  17. Phytomorphology v.1 The shoot apex in Gymnosperms Johnson MA
  18. Ph.D. Thesis White spruce somatic embryogenesis Kong L
  19. Somatic Embryogenesis in Woody Plants v.4 Somatic embryogenesis in white spruce: studies of embryo development and cell biology Kong L;Attree SM;Evans DE;binarova P;Yeung EC;Fowke LC;Mohan Jain S(ed.);Gupta P(ed.);Newton R(ed.)
  20. In Vitro Cell. Dev. Biol. v.28P Development of white spruce somatic embryos:Ⅱ. Continual shoot meristem development during germination Kong L;Yeung EC
  21. Plant Sci. v.104 Effects of ethylene and ethylene inhibitors on white spruce somatic embryo maturation Kong L;Yeung EC
  22. Physiol. Plant v.93 Effects of silver nitrate and polyethylene glycol on white spruce (Picea glauca) somatic embryo development: enhancing cotyledonary embryo formation and endogenous ABA content Kong L;Yeung EC
  23. Growth Pattems in Vascular Plants The Angiosperm embryo: correlative controls in development, differentiation, and maturation Krishnamurthy KV;Iqbal M(ed.)
  24. Bull. Torrey Bot. Club. v.63 The growth of plant embryos in culture LaRue CD
  25. Development v.122 The WUSCHEL gene is required for shoot and floral meristem integrity in Arabidopsis Laux T;Mayer KFX;Berger J;Jrgens G
  26. Curr. Opin. Plant Biol. v.2 Shoot meristem formation and maintenance Lanhard M;Laux T
  27. Development v.125 The development of apical embryonic pattem in arabidopsis Long JA;Barton MK
  28. Cell v.95 Role of WUSCHEL in regulating stem cell fate in the Arabidopsis shoot meristem Mayer KFX;Schoof H;Haecker A;Lenhard M;Jgens G;Laux T
  29. Amer. J. Bot. v.32 Studies in the development anatomy of Phlox drummondii Hook.Ⅰ. The embryo Miller HA;Wetmore RH
  30. EMBO J. v.17 Role of the ZWILLE gene in the regulation of central shoot meristem cell fate during Arabidopsis embryogenesis Moussian B;schoof H;Haecker A;Jrgens G;Laux T
  31. Amer. J. Bot v.80 Failure to establish a functional shoot meristem may be a cause of conversion failure in somatic embryos of Daucus carota (Apiaceae) Nickle TC;Yeung EC
  32. In Vitro Cell. Dev. Biol.-Plant v.30P Further evidence of a role for abscisic acid in conversion of somatic embryos of Daucus carota Nickle TC;Yeung EC
  33. Experimental Embryology of Vascular Plants Experimental embryology of Gymnosperms Norstog K;Johri BM(ed.)
  34. Experimental embryogenesis in vascular plants Raghavan V
  35. Molecular embryology of flowering plants Reghavan V
  36. In Vitro Embryogenesis in Plants Zygotic embryogenesis in Gymnosperms and Angiosperms Reghavan V;Sharma KK;Thorpe TA(ed.)
  37. M.Sc. Thesis Physiological control of shoot apical meristem formation in Brassica napus cv $\'{T}$opas Ramesar-Fortner N
  38. Can. J. Bot. v.68 Synchronous and high frequency germination of interior sqruce somatic embryos following partial drying at high relative humidity Roberts DR;Sutton BC;Flinn BS
  39. Embrhology of Gymnosperms Singh H
  40. Amer. J. Bot v.36 Histogenesis and organization of the embryo in Pinus strobus L. Spurr AR
  41. In Vitro Cell. Dev. Biol. - Plant v.35 Ascorbic acid improves conversion of white spruce somatic embryos Stasolla C;Yeung EC
  42. Pattems in Plant Development Steeves TA;Sussex IM
  43. Proc. Natl. Acad. Sci. USA v.95 A homeobox gene with potential developmental control function in the meristem of the conifer Picea abies Sundas-Larsson A;Svenson M;Liao H;Engstrom P
  44. In Vitro Embryogenesis in Plants Thorpe TA(ed.)
  45. Bot. Mag. v.1 Determination in plant development Wareing PF
  46. British Plant Growth Regulator Group, Monograph v.3 What is the basis of the stability of apical meristems? Wareing PF
  47. Development v.125 The HOBBIT gene is required for formation of the root meristem in the Arabidopsis embryo Willemsen V;Wolkenfelt H;de Vrieze G;Weisbeek P;Scheres B
  48. Planta v.182 Abscisic acid and osmoticum prevent germination of developing alfalfa embryos, but only osmoticum maintains the synthesis of developmental proteins Xu N;Coulter KM;Bewley JD
  49. In Vitro Embryogenesis in Plants Structural and developmental pattems in somatic embryogenesis Yeung EC;Thorpe TA(ed.)
  50. In Vitro Cell. Dev. Biol.- Plant v.35 The use of histology in the study of plant tissue culture systems - some practical comments Yeung EC
  51. Bot. Gaz. v.142 Shoot histogenesis in cotyledon explants of radiata pine Yeung EC;Aitken J;Biondi S;Thorpe TA
  52. Z. Pflanzenphysiol v.106 The osmotic environment of developing embryos of Phaseolus vulgaris Yeung EC;Brown DCW
  53. Int. J. Plant Sci. v.157 Comparative development of zygotic and microspore-derived embryos in Brassica napus L. cv. Topas. I. Histodifferentiation Yeung EC;Rahman MH;Thorpe TA
  54. Can. J. Bot. v.76 Apical meristem formation during zygotic embryo development of white spruce Yeung EC;Stasolla C;Kong L
  55. Z. Pflanzenphysiol v.91 Embryogeny of Phaseolus coccineus: the suspensor and the growth of the embryo-proper in vitro Yeung EC;Sussex IM