The branching of Trichomanes proliferum (Hymenophyllaceae)

The general morphology, anatomy, and meristem histology of Trichomanes proliferum were studied in order to explain the morphogenesis of this fern. As opposed to Bierhorst's conclusions, T. proliferum was found to be a typical fern with normal tetrahedral shoot apical cells and lenticular leaf apical cells. The leaf is a lateral production of the shoot apical meristem. This species is similar morphologically to other species in the genus Trichomanes: the shoot apical meristems on the creeping stolons produce "lateral systems," composed of a leaf and a bud, which are extraaxillary, as in other Trichomanes species with a creeping filiform stolon. The unique morphology of this fern is due to two supplementary branching systems: a lateral branching of the stolon, which is leafless at the fork, and an epiphyllous budding, which results in the formation of additional leaves by a different process of development. Key words: fern, branching, morphogenesis, histogenesis, epiphyllous buds.

Download Full-text

The shoot apical meristem: an historical perspectiveThis review is one of a selection of papers published on the Special Theme of Shoot Apical Meristems.

Canadian Journal of Botany ◽

10.1139/b06-144 ◽

2006 ◽

Vol 84 (11) ◽

pp. 1629-1633 ◽

Cited By ~ 1

Author(s):

Taylor A. Steeves

Keyword(s):

Genetic Analysis ◽

Shoot Apical Meristem ◽

Apical Meristem ◽

Molecular Genetic ◽

Molecular Genetic Analysis ◽

Seed Plants ◽

Shoot Apices ◽

Early 19Th Century ◽

Apical Meristems ◽

Shoot Apical Meristems

Although much of the current investigation of shoot apical meristems is in the realm of molecular genetic analysis, it is important that previous structural and functional studies not be overlooked as essential background to these studies. Since Caspar Friedrich Wolff described the shoot apical meristem in 1759, many and varied interpretations have arisen. In the early 19th century, the apical cell was recognized in seedless vascular plants and this interpretation was extended to seed plants. However, by the 1860s, this view was replaced in seed plants by the histogen concept, which recognized meristem layers in the apical meristem giving rise to specific tissues. In 1924, the tunica–corpus interpretation of angiosperm shoot apices became widespread, the two regions being distinguished by different planes of cell division. In the 1950s, the “méristème d’attente” concept appeared in France, which argued that the central region of the apex remained essentially inactive until the onset of flowering. Meanwhile, the recognition of zonation patterns in angiosperm and gymnosperm shoot apices assumed growing functional importance. Clonal analysis based on chimeras in the meristem indicated the presence of initial cells but also their replacement. Surgical experimentation and culture of excised apices in vitro stressed the autonomy of the shoot apex and its role in shoot development. Present molecular genetic analysis may help to resolve some of the persistent questions concerning the organization and functioning of shoot apical meristems.

Download Full-text

Molecular and cellular aspects of the shoot apical meristems organization of vascular plants

Biological Communications ◽

10.21638/spbu03.2015.402 ◽

2015 ◽

Author(s):

Ekaterina Klimova ◽

Olga Voitsekhovskaja

Keyword(s):

Transcription Factors ◽

Shoot Apical Meristem ◽

Vascular Plants ◽

Apical Meristem ◽

Flowering Plants ◽

Knox Genes ◽

Apical Meristems ◽

Autonomous Regulation ◽

Shoot Apical Meristems

Transfer of developmental regulators, such as miRNA and transcription factors, through plasmodesmata represents one of the key mechanisms regulating morphogenesis in angiosperms. This mechanism has been termed non-cell-autonomous regulation. At present it is not known whether this process is involved in the morphogenesis of plants belonging to the evolutionarily ancient taxa. Importantly, structure and symplastic organization of apical meristems in the representatives of such taxa significantly differ from those in flowering plants. The non-cell-autonomous transcription factors encoded by the KNOX genes which regulate functions of the shoot apical meristem may become a promising model to study this issue. Refs 102. Figs 3.

Download Full-text

Callus induction from shoot apical meristem in Triticum spelta L. and T. aestivum L.

Faktori eksperimental'noi evolucii organizmiv ◽

10.7124/feeo.v25.1169 ◽

2019 ◽

Vol 25 ◽

pp. 237-242

Author(s):

A. V. Kyriienko ◽

M. F. Parii ◽

Yu. V. Symonenko ◽

M. V. Kuchuk ◽

N. L. Shcherbak

Keyword(s):

Common Wheat ◽

Callus Induction ◽

Shoot Apical Meristem ◽

Plant Material ◽

Apical Meristem ◽

Triticum Spelta ◽

Apical Meristems ◽

Shoot Apical Meristems ◽

Positive Effect ◽

Wheat Callus

Aim. To develop an effective protocol for callus induction from shoot apical meristem in Triticum spelta L. and T. aestivum L. Methods. Plant material: spelt “Europe” and common wheat “Bunchuk”. For this research we used shoot apical meristems from 3-days plants. For callus induction we proposed 4 media with different concentration of 2,4-D, picloram, NAA and AgNO3. Explants were growing in dark during 21 day at + 25 C. Results. Calli were transparent and mild, less than 8 mm. For callus induction positive effect were shown on media with 2,4-D and picloram. At the same time, NAA was not such effective. Conclusions. In our research was shown, that the best media for spelt callus induction should have 2 mg/l 2,4-D and 10 mg/l AgNO3. Keywords: callusogenesis, spelt (Triticum spelta L.), common wheat, callus, shoot apical meristem.

Download Full-text

Class I KNOX Is Related to Determinacy during the Leaf Development of the Fern Mickelia scandens (Dryopteridaceae)

International Journal of Molecular Sciences ◽

10.3390/ijms21124295 ◽

2020 ◽

Vol 21 (12) ◽

pp. 4295 ◽

Cited By ~ 4

Author(s):

Rafael Cruz ◽

Gladys F. A. Melo-de-Pinna ◽

Alejandra Vasco ◽

Jefferson Prado ◽

Barbara A. Ambrose

Keyword(s):

Leaf Development ◽

Apical Meristem ◽

Class I ◽

Seed Plants ◽

Histone H4 ◽

Knox Genes ◽

Apical Meristems ◽

Cell Divisions ◽

Shoot Apical Meristems

Unlike seed plants, ferns leaves are considered to be structures with delayed determinacy, with a leaf apical meristem similar to the shoot apical meristems. To better understand the meristematic organization during leaf development and determinacy control, we analyzed the cell divisions and expression of Class I KNOX genes in Mickelia scandens, a fern that produces larger leaves with more pinnae in its climbing form than in its terrestrial form. We performed anatomical, in situ hybridization, and qRT-PCR experiments with histone H4 (cell division marker) and Class I KNOX genes. We found that Class I KNOX genes are expressed in shoot apical meristems, leaf apical meristems, and pinnae primordia. During early development, cell divisions occur in the most distal regions of the analyzed structures, including pinnae, and are not restricted to apical cells. Fern leaves and pinnae bear apical meristems that may partially act as indeterminate shoots, supporting the hypothesis of homology between shoots and leaves. Class I KNOX expression is correlated with indeterminacy in the apex and leaf of ferns, suggesting a conserved function for these genes in euphyllophytes with compound leaves.

Download Full-text

The morphogenetic rôle of apical meristems: fundamental aspects (illustrated by means of the shoot apical meristem)

Differentiation and Development / Differenzierung und Entwicklung ◽

10.1007/978-3-662-36273-0_15 ◽

1965 ◽

pp. 443-451

Author(s):

C. W. Wardlaw

Keyword(s):

Shoot Apical Meristem ◽

Apical Meristem ◽

Apical Meristems

Download Full-text

Cauline meristems in leptosporangiate ferns: structure, lateral appendages, and branching

Canadian Journal of Botany ◽

10.1139/b93-196 ◽

1993 ◽

Vol 71 (12) ◽

pp. 1612-1624 ◽

Cited By ~ 9

Author(s):

R. Hébant-Mauri

Keyword(s):

Key Words ◽

Early Development ◽

Shoot Apical Meristem ◽

Apical Meristem ◽

Main Stem ◽

Adult Plant ◽

Structure Morphology

This study on shoot apical meristem structures in leptosporangiate ferns examines the precise initiation of lateral appendages in the meristems. Interrelationships and early development of the main stem, fronds, and branches are described. Ontogeny and histology within the apical meristem must be considered in a reasonable morphological interpretation of the adult plant, especially with respect to the lateral system (i.e. frond and bud assemblage) in creeping branched ferns. Key words: branching, lateral initiations, meristem structure, morphology, ontogeny.

Download Full-text