Cell cycle changes during callus initiation from cultured maize embryos. An autoradiographic study

Fransz, Paul; Kieft, H.; Schel, J.H.N.

doi:10.1111/j.1438-8677.1990.tb01447.x

Cited by 8 publications

(2 citation statements)

References 27 publications

(20 reference statements)

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“…2,4-D is able to cause various irregularities in cells cultivated in vitro (Bayliss 1980, Ager et al 1991, Pavlika et al 1991. The mutagenic influence of 2,4-D takes place as unorganized rapid cell growth (Karp 1991) and depends on the genotype (Fransz et al 1990).…”

Section: Introductionmentioning

confidence: 99%

Effect of 2,4-dichlorophenoxyacetic acid on nuclear division in stem segments ofPisum sativum L. cultivatedin vitro

Gantchev¹,

Bleiss²

1994

Biol. plant.

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We have investigated the influence of 2,4-dichlorophenoxyacetic acid (2,4-D) on the appearance of nuclear fragments, caused by direct nuclear division, as well as on mitotic activity in cultivated internodial stem segments of Pisum sativum L., cv. BOrdi, during 180 d of cultivation. Direct nuclear fragmentation (dNF) was indicated by the shape and structure of the nucleus as well as by the occurrence of 1C-and 3C-values of DNA, investigated cytophotometrically. The dNF occurred during the whole cultivation period in segments treated by 2,4-D in concentrations from 4 to 32 mg 1-1. In the presence of 2 mg 1 -t of 2,4-D .the dNF existed in the explants only up to 90 d. Mitotic activity was not observed in the 2,4-D-free control but occurred during the whole cultivation period when 2,4-D was added in concentrations from 2 to 16 mg 1-1. In the presence of 32 mg 1 -l of 2,4-D the level of mitotic activity was very low at the beginning and ceased after 60 d in culture.

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Section: Introductionmentioning

confidence: 99%

Effect of 2,4-dichlorophenoxyacetic acid on nuclear division in stem segments ofPisum sativum L. cultivatedin vitro

Gantchev¹,

Bleiss²

1994

Biol. plant.

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“…In both inbreds, the 1st day of culture is characterized by cytologic changes, such as an increase in the number of organelles, and changes in vacuolation and nuclear morphology. Determination of the incorporation of [ 3 H]thymidine in the scutellum showed that the lines had similar mitotic indexes (Fransz et al 1990). This early phase is called the shock response phase, and aforementioned characteristics also occur in the absence of 2,4-D Schel 1987, 1991).…”

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confidence: 99%

Distribution of [14C] Dichlorophenoxyacetic Acid in Cultured Zygotic Embryos of Zea mays L.

Bronsema

Oostveen

Prinsen

et al. 1998

J Plant Growth Regul

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The uptake of 2,4-dichlorophenoxyacetic acid (2,4-D), necessary for the in vitro induction of callus formation and somatic embryogenesis in cultured immature maize embryos, was quantified after culture on nutrient medium with [ 14 C]2,4-D. The identity of the 14 C label in the embryos was determined by high performance liquid chromatography (HPLC), and its distribution within embryos was visualized on sections of plastic embedded material. Quantification of the 14 C label after a pulse label of 16 h showed a hundredfold accumulation of 2,4-D in the embryos with respect to the initial medium concentration. During tissue processing for in situ detection of 14 C, however, up to 70% of the label disappeared because of the embedding process. The best structural preservation was obtained after ethanol-mediated infiltration of Technovit 7100. Water-mediated infiltration of Technovit 7100 gave the highest retention of 14 C. HPLC analysis showed that more than 95% of the residual 14 C label found in embryos was still 2,4-D. Autoradiography showed that the embryogenic inbred line A188 contained 14 C label in distinct regions of the scutellum, coleoptile, and suspensor. The nonembryogenic inbred line A632 contained more label after 16 h of culture in a different distribution compared with A188. Subculture of the embryos for 24 and 72 h and histologic analysis showed that cell proliferation and callus formation were restricted to specific regions of the embryo in both inbred lines. The pattern of 2,4-D distribution did not codistribute with regions of proliferation, indicating that 2,4-D is not the only trigger for proliferation.

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The ultrastructure of somatic embryo development in pearl millet (Pennisetum glaucum; Poaceae)

Taylor

Vasil

1996

American J of Botany

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The ultrastructure, morphology, and histology of somatic embryogenesis in pearl millet (Pennisetum glaucum) were examined using light and electron microscopic techniques. Somatic embryogenesis was initiated from zygotic embryo explants cultured =8 d after pollination. Formation of a ridge of tissue began 3--4 d after culture (DAC) by divisions in the epidermal and subepidermal cells of the scutellum. Ridge formation was accompanied by a decrease in vacuoles, lipid bodies, and cell size, and an increase in endoplasmic reticulum (ER). Proembryonic cell masses (proembryoids) formed from the scutellar ridge by 10 DAC. Proembryoid cells had abundant Golgi bodies and ER while the amounts of lipids and starch varied. Somatic embryos developed from the proembryonic masses 13 DAC and by 21 DAC had all the parts of mature zygotic embryos. Although shoot and root primordia of somatic embryos were always less differentiated than those of zygotic embryos, scutellar cells of somatic and zygotic embryos had similar amounts of lipids, vacuoles, and starch. Somatic scutellar epidermal cells were more vacuolated than their zygotic counterparts. In contrast, somatic scutellar nodal cells were smaller and not as vacuolated as in zygotic embryos. Somatic embryogenesis was characterized by three phases of cell development: first, scutellar cell dedifferentiation with a reduction in lipids and cell and vacuole size; second, proembryoid formation with high levels of ER; and third, the development of somatic embryos that were functionally and morphologically similar to zygotic embryos.

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Cell cycle changes during callus initiation from cultured maize embryos. An autoradiographic study

Cited by 8 publications

References 27 publications

Effect of 2,4-dichlorophenoxyacetic acid on nuclear division in stem segments ofPisum sativum L. cultivatedin vitro

Effect of 2,4-dichlorophenoxyacetic acid on nuclear division in stem segments ofPisum sativum L. cultivatedin vitro

Distribution of [14C] Dichlorophenoxyacetic Acid in Cultured Zygotic Embryos of Zea mays L.

The ultrastructure of somatic embryo development in pearl millet (Pennisetum glaucum; Poaceae)

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