Anatomy, histochemistry and ultrastructure of seed and somatic embryo of Acrocomia aculeata (Arecaceae)

Macaw palm (Acrocomia aculeata (Jacq.) Lodd. ex Mart.) is a tropical species with multiple uses, including oil supply for biodiesel production. However, structural and physiological studies of the seed are still scarce, as well as in vitro propagation techniques. The aim of this study was to characterize the anatomy, histochemistry and ultrastructure of the seed and the in vitro somatic embryo of A. aculeata, gaining insight into relationships between the post-harvest seed behavior and the somatic embryo conversion to plant. The zygotic embryo and the endosperm show high quantities of protein and lipids, stored in protein and lipid bodies, respectively. The cell wall storage polysaccharides occur in the thickened cell wall of the endosperm. The absence of vacuoles and the few organelles, except for the storage ones, indicate low metabolic state of the zygotic embryo, which suggests a orthodox behavior of the seed at maturity. The somatic embryo shows a shoot meristem with few leaf primordia, vacuolated cells and, occasionally, amyloplasts , but not lipid or protein reserves. These characteristics, common in somatic embryogenesis, could be associated with the maturation phase, and, consequently, with the low conversion of these embryos into plants.

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Coconut Tissue Culture: The Indian Initiatives, Experiences and Achievements

CORD ◽

10.37833/cord.v33i2.48 ◽

2017 ◽

Vol 33 (2) ◽

pp. 11

Author(s):

Anitha Karun

Keyword(s):

Tissue Culture ◽

Somatic Embryos ◽

Culture Media ◽

Zygotic Embryo ◽

Shoot Meristem ◽

Direct Organogenesis ◽

Zygotic Embryos ◽

Immature Inflorescence ◽

High Yielding Varieties

Coconut is one of the principal crops of India cultivated in over 35 districts mainly in the southern states. The productivity of the crop is declining in many of the traditionally cultivated regions owing to ageing plantations as well as biotic and abiotic stresses. These plantations are to be replanted with high yielding varieties/hybrids for which adequate quantity of quality planting material is not available. Even though tissue culture research was initiated in many laboratories in the country, the work was eventually phased out in most of the laboratories for want of a repeatable protocol. At ICAR-CPCRI, coconut tissue culture programs have been continuing for the past three decades. The attempts made include experimentation with different explants viz., immature inflorescence, plumular tissues, mature palm shoot meristem, ovary and anthers and different culture media supplemented with varying levels and types of hormones. Some of the successful protocols developed at the Institute include coconut zygotic embryo culture for collection and exchange of germplasm, cryopreservation and retrieval of zygotic embryos and pollen and plantlet regeneration from plumular tissues. Even though ICAR-CPCRI has succeeded in obtaining plantlets via direct organogenesis from inflorescence explants, the absence of friable calli formation from explants, the low rate of somatic embryo formation, large number of cultures turning to abnormal shoot development, non conversion of somatic embryos into plantlets, and formation of abnormal somatic embryos remain the major bottlenecks. Gene expression studies are being currently undertaken to decipher the molecular basis of in vitro recalcitrance.

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Developmental changes of catalase and superoxide dismutase isoenzymes in zygotic and somatic embryos of horse chestnut

Functional Plant Biology ◽

10.1071/pp98068 ◽

1998 ◽

Vol 25 (8) ◽

pp. 909 ◽

Cited By ~ 16

Author(s):

F. Bagnoli ◽

M. Capuana ◽

M. L. Racchi

Keyword(s):

Superoxide Dismutase ◽

Somatic Embryogenesis ◽

Somatic Embryo ◽

Zygotic Embryo ◽

Electrophoretic Analysis ◽

Horse Chestnut ◽

Zygotic Embryogenesis ◽

Native Page ◽

Cat Isoforms

Catalase (CAT) and superoxide dismutase (SOD), two of the major antioxidant enzyme systems, were examined by native PAGE at different stages of zygotic and somatic embryogenesis of horse chestnut (Aesculus hippocastanum L.). During both zygotic and somatic embryogenesis, CAT and SOD specific activities increased, but electrophoretic analysis revealed remarkable differences in the isoenzyme patterns. Two CAT isoforms were differentially present during zygotic embryogenesis. The transition from the fast to the slow migrating form occurred in July, approximately 2 months after pollination. In contrast to zygotic, the two isoforms were continuously detectable during somatic embryo-genesis. In fact, with the exception of the callus stage, in which only one form was present, both of the CAT isoforms are equally active during the somatic embryo development. Unlike CAT, all SOD isoenzymes, one Mn-SOD and five Cu/Zn-SODs, were present during all the stages of zygotic embryo formation, but only Mn-SOD and an Fe-SOD were detected during somatic embryogenesis. These results suggest the occurrence of oxidative stress conditions during in vitro culture which, in horse chestnut, could account for the difficulties observed in the development of the somatic embryo into a plantlet.

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Temperature and GA3 on ROS and cytogenetic stability during in vitro cultivation of strelitzia zygotic embryos

Ciência e Agrotecnologia ◽

10.1590/1413-7054202145020220 ◽

2021 ◽

Vol 45 ◽

Author(s):

Júnia Rafael Mendonça Figueiredo ◽

Patrícia Duarte de Oliveira Paiva ◽

Diogo Pedrosa Corrêa da Silva ◽

Renato Paiva ◽

Rafaela Ribeiro Souza ◽

...

Keyword(s):

Zygotic Embryo ◽

Reductase Activity ◽

Germination Rate ◽

Tropical Species ◽

Zygotic Embryos ◽

In Vitro Cultivation ◽

In Vitro Development ◽

C 30 ◽

Vitro Development

ABSTRACT Tropical species may require higher temperatures as well as higher growth regulator concentrations for in vitro development. Since these conditions may affect plant metabolism, the objective of this study was to identify how different temperatures and gibberellin concentrations may affect the in vitro development of strelitzia embryos, analyzing the effect on ROS and cytogenetic stability. Zygotic embryos were cultivated on MS medium supplemented with 5, 10 and 20 µM GA3 under temperatures of 25 °C, 30/25 °C and 30 °C. After 60 days, higher embryonic germination rate (72%) and shoot length of plantlets (3.14 cm) were observed on medium containing 20 µM gibberellic acid (GA3). At this concentration, there was an increase in nitrate reductase activity with no change in the cytogenetic stability. The temperature influenced only shoot and root lengths, which were highest at 25 °C. At 30 °C, superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities increased compared with those at 25 °C. Thus, the addition of 20 µM GA3 to the culture medium and a temperature of 25 °C in the growth room should be used for zygotic embryo culture of strelitzia.

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DEVELOPMENTAL AND REGULATORY MECHANISMS INVOLVED IN PECAN SOMATIC EMBRYO MATURATION

HortScience ◽

10.21273/hortsci.25.9.1154f ◽

1990 ◽

Vol 25 (9) ◽

pp. 1154f-1154

Author(s):

Hazel Y. Wetzstein ◽

Choong-Suk Kim

Keyword(s):

Somatic Embryo ◽

Cold Treatment ◽

Limiting Factor ◽

Embryo Maturation ◽

Electron Microscopic ◽

Low Frequencies ◽

Transmission Electron ◽

Somatic Embryo Conversion ◽

Somatic Embryogenic

Although somatic embryogenesis in vitro has been carried out successfully in a number of plants, a limiting factor in many somatic embryogenic systems is that plantlet regeneration is not obtainable or restricted to low frequencies. We have developed a repetitive, high frequency somatic embryogenic system in pecan (Carya illinoensis) and have identified effective treatments for improved somatic embryo conversion. A 6 to 10 week cold treatment followed by a 5 day desiccation, promoted enhanced root germination and extension, and epicotyl elongation. Light and transmission electron microscopic evaluations of somatic embryo cotyledon development will be presented and related to conversion enhancing treatments and their possible roles in embryo maturation.

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DEVELOPMENTAL AND REGULATORY MECHANISMS INVOLVED IN PECAN SOMATIC EMBRYO MATURATION

HortScience ◽

10.21273/hortsci.25.9.1154 ◽

1990 ◽

Vol 25 (9) ◽

pp. 1154F-1154 ◽

Cited By ~ 1

Author(s):

Hazel Y. Wetzstein ◽

Choong-Suk Kim

Keyword(s):

Somatic Embryo ◽

Cold Treatment ◽

Limiting Factor ◽

Embryo Maturation ◽

Electron Microscopic ◽

Low Frequencies ◽

Transmission Electron ◽

Somatic Embryo Conversion ◽

Somatic Embryogenic

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In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100083035 ◽

1978 ◽

Vol 36 (2) ◽

pp. 434-435

Author(s):

D. Reis ◽

B. Vian ◽

J. C. Roland

Keyword(s):

Cell Wall ◽

Self Assembly ◽

Plant Cell Wall ◽

Higher Plants ◽

Three Dimensional ◽

Cytochemical Study ◽

Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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In vitro assembly of 2-D crystals from partially purified EA1 protein secreted by Bacillus anthracis strain Delta Sterne-1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100169110 ◽

1994 ◽

Vol 52 ◽

pp. 276-277

Author(s):

Mary Beth Downs ◽

Wilson Ribot ◽

Joseph W. Farchaus

Keyword(s):

Cell Wall ◽

Molecular Sieves ◽

Cell Envelope ◽

Single Species ◽

Supporting Cell ◽

Surface Layers ◽

Rabbit Igg ◽

In Vitro Assembly ◽

Covalently Linked

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.

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Histological aspects of the cryopreservation of potato

Acta Agronomica Hungarica ◽

10.1556/aagr.56.2008.3.10 ◽

2008 ◽

Vol 56 (3) ◽

pp. 341-348

Author(s):

P. Pepó ◽

A. Kovács

Keyword(s):

Cell Wall ◽

Low Temperatures ◽

Cell Walls ◽

Cellular Level ◽

Adaptive Mechanism ◽

Epidermal Layer ◽

Freezing And Thawing ◽

Meristematic Cells ◽

Suitable Solution ◽

Vacuolated Cells

Cryopreservation appears to be a suitable solution for the maintenance of potato germplasms. The protocol described in this paper can be applied for the vitrification and preservation of meristems. During histo-cytological studies it is possible to observe modifications at the cellular level and to understand the adaptive mechanism to low temperatures. Control potato meristem tissue contained a number of meristematic cells with a gradient of differentiation. After freezing there were a large number of vacuolated cells, some of which exhibited broken cell walls and plasmolysis. The thickening of the cell wall, giving them a sinuous appearance, was observed after freezing and thawing the meristems, with ruptures of the cuticle and epidermal layer.

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