Developmental biology of embryogenesis from carrot culture

Sung, Z. Renee; Fienberg, Allen A.; Chorneau, Robert; Borkird, Chumpol; Furner, Ian J.; Smith, Jane A.; Terzi, Mario; Loschiavo, F; Giuliano, Giovanni; Pitto, Letizia; Nuti-Ronchi, V.

doi:10.1007/bf02885641

Cited by 60 publications

(23 citation statements)

References 21 publications

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“…In the presence of 2,4-D unorganized growth of the cells is promoted, while in its absence the carrot cells usually differentiate into somatic embryos (15,20). Although embryo formation has been subjected to intense morphological as well as biochemical studies (6,7,10,12,20,23) the regulation of this process is far from elucidated. This lack of understanding may in part be explained by the difficulties to obtain high yields of synchronously developing embryos.…”

Section: Introductionmentioning

confidence: 99%

“…This lack of understanding may in part be explained by the difficulties to obtain high yields of synchronously developing embryos. Many studies have focused on biochemical changes occurring during the switch from callus growth to embryo formation, such as altered rate of DNA, RNA, and protein synthesis (8) or quantitative changes in different enzyme activities (12,23,24). Furthermore, some unique properties of differentiating carrot cells have recently been described.…”

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confidence: 99%

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Purification of a Trypsin Inhibitor Secreted by Embryogenic Carrot Cells

Carlberg¹,

Jonsson²,

Bergenstråhle³

et al. 1987

Plant Physiol.

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A protease inhibitor with a molecular weight of about 12,800 was purified to electrophoretic homogeneity from Daucuis carota cells. The protease inhibitor was heat stable and inhibited trypsin but had no activity toward chymotrypsin or subtilisin. Nonembryogenic as well as embryogenic strains contained the inhibitor in similar amounts, but in the embryogenic strains the trypsin inhibitor was released from the cells and as a result accumulated in high concentrations in the culture medium, whereas no release of the trypsin inhibitor was found during cultivation of the nonembryogenic strains. Very low amounts of acid phosphatase or a-mannosidase activity were found in the culture filtrate of both embryogenic and nonembryogenic strains, which suggest that the release of the inhibitor from embryogenic strains was not due to cell lysis.Carrot cell cultures provide a simple system for studies on somatic embryogenesis in plants, since the differentiation process in these cultures can be easily manipulated by exogenously supplied auxin. In the presence of 2,4-D unorganized growth of the cells is promoted, while in its absence the carrot cells usually differentiate into somatic embryos (15,20). Although embryo formation has been subjected to intense morphological as well as biochemical studies (6,7,10,12,20,23) the regulation of this process is far from elucidated. This lack of understanding may in part be explained by the difficulties to obtain high yields of synchronously developing embryos. Many studies have focused on biochemical changes occurring during the switch from callus growth to embryo formation, such as altered rate of DNA, RNA, and protein synthesis (8) or quantitative changes in different enzyme activities (12,23,24). Furthermore, some unique properties of differentiating carrot cells have recently been described. Sung and Okimoto (21) reported that two polypeptides are synthesized exclusively during embryo formation and these polypeptides may therefore be used as markers for the differentiation process.During embryo formation some carrot strains have the ability to inactivate the fungal toxins cycloheximide (22) and a-amanitin (14) supplied to the culture medium. The mechanism for this inactivation has not been clarified, although the enzyme tyrosinase (phenoloxidase) has been proposed as responsible for degradation of a-amanitin since high activity of this enzyme was observed exclusively during embryogenesis in these carrot strains (14).It is well established that during prolonged culture in 2,4-Dcontaining medium, carrot cell strains generally lose their embryogenic capacity and become nonembryogenic (19). We have 'Supported by the Swedish Natural Science Research Council. used embryogenic and nonembryogenic carrot strains in order to characterize strains with the capacity to form embryos. In a previous paper (3) we have shown that activity of the enzyme phenoloxidase in carrot is restricted to embryogenic strains. Moreover, the activity of this enzyme decreases concomitant with a decline in emb...

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Purification of a Trypsin Inhibitor Secreted by Embryogenic Carrot Cells

Carlberg¹,

Jonsson²,

Bergenstråhle³

et al. 1987

Plant Physiol.

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“…established system for the study of morphogenesis in plants using molecular biology methods (Fujimura and Komamine, 1979;Sung et al, 1984). In severa1 studies, changes in the content of a molecular marker during somatic embryogenesis have been correlated with the rate of cell proliferation (Smith et al, 1988;Dudits et al, 1991;Hirt et al, 1991).…”

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confidence: 99%

Isolation and Characterization of a cDNA Clone for Plant Nuclear Antigen 21D7 Associated with Cell Division

Smith¹,

Ito²,

Yamada³

et al. 1993

Plant Physiol.

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A cDNA clone was isolated from a carrot (Daucus carota 1.) cDNA expression library using monoclonal antibody 21D7, which recognizes a nuclear antigen associated with cell division in plant cells. To show that the isolated cDNA encodes the 21D7 antigen, a polyclonal antiserum was raised against a recombinant fusion protein specified by the cDNA. 60th the polyclonal antiserum and the monoclonal antibody 21D7 recognized the same plant protein on immunoblots, in immunoprecipitation experiments, and in peptide mapping. Analysis of the cDNA revealed that the deduced amino acid sequence has 45% identity to the predicted sequence of the mouse transplantation antigen P91A from mutant tumor cells that is responsible for the immune rejection of the corresponding cell clone in a syngeneic mouse. The expression of the plant cDNA at the mRNA level was highly correlated with cell proliferation. In Carrot (Daucus carota L.) cell cultures provide a wellestablished system for the study of morphogenesis in plants using molecular biology methods (Fujimura and Komamine, 1979;Sung et al., 1984). In severa1 studies, changes in the content of a molecular marker during somatic embryogenesis have been correlated with the rate of cell proliferation (Smith et al., 1988;Dudits et al., 1991;Hirt et al., 1991). Smith et al. (1985) used an immunochemical approach to identify antigen markers of low abundance that were preferentially expressed in somatic embryos. A large pane1 of hybridoma clones was generated and screened for production of antibodies that were more reactive with crude homogenates from carrot somatic embryos than with those from carrot cell suspensions. For further work, hybridoma 21D7 was chosen because its antibody, Mab 21D7, detected a single, clear band with a molecular mass of 45 kD on blots of SDS-treated carrot proteins (Smith et al., 1985). Analysis of tissue specificity of the 21D7 antigen using Mab 21D7 revealed that only rapidly growing parts of carrot seedlings and dividing cells in carrot suspension cultures contained detectable levels of this protein (Smith et al., 1988); cross-reacting antigens were observed in rapidly proliferating tissues of many other plant species. When plant cells were separated into soluble, nuclear, and membrane fractions, the nuclear fraction was found to be highly enriched in the 21D7 antigen. Indirect immunofluorescence studies confirmed that the antigen was localized in the nucleus, most prominently in the nucleolus (Smith et al., 1988). However, the level of the antigen was too low to purify it by routine methods (Smith et al., 1988).In the present study, the cDNA clone for 21D7 antigen was isolated from a carrot expression library using the Mab 21D7. Here we present the sequence of the carrot cDNA and describe the pattern of expression at the mRNA level in different carrot tissues. To analyze the correlation between cell division and expression of the gene for 21D7 antigen, the corresponding periwinkle (Catharanthus roseus [L.] G Don.) cDNA was isolated from a cDNA library and utilize...

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“…Carrots constitute a good system to investigate somatic embryogenesis, as useful embryo induction systems have been developed for this species (Zimmerman 1993). Carrot somatic embryos can be readily induced synchronously, in large quantities, by the transfer of embryogenic cells (EC) from auxin-containing medium to auxinfree medium (Steward et al 1958, Reinert 1959, Sung et al 1984, Kiyosue et al 1993a, 1993b (Satoh et al 1986). Several embryo-specific genes have been isolated and characterized by comparison of gene or protein expression in EC, NC, and somatic embryos (Wilde et al 1988, Kiyosue et al 1991, 1993a, 1993b, Lin et al 1996, Tachikawa et al 1998.…”

Section: Introductionmentioning

confidence: 99%

Isolation of putative embryo-specific genes using stress induction of carrot somatic embryos

2009

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Little is known about the physiological responses of higher plant cells during the early stages of embryogenesis and the genes that are involved in these responses. Carrot is an appropriate plant for the study of somatic embryogenesis as a model of zygotic embryogenesis. The system of stress induction of carrot somatic embryogenesis is useful for isolating genes expressed during embryogenesis, as embryogenic competence and the expression of certain embryo-specific genes increases with increased stress. Fluorescent differential display (FDD) was performed to isolate stress-induced genes in carrot somatic embryos, and five genes were isolated as embryonic tissue-specific genes. One of these genes was expressed until the early torpedo-shaped stage of zygotic embryogenesis. This result suggested that in the stress-induction system of carrot somatic embryos, embryo-specific genes expressed in the early stages of embryogenesis were induced during somatic embryo induction by stress treatment, concomitant with acquisition of embryonic competence. Unique genes expressed during early embryogenesis can be isolated from carrot by combining the appropriate experimental system and FDD. This strategy could be applied to many plant species for which genome information is not yet available.

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Developmental biology of embryogenesis from carrot culture

Cited by 60 publications

References 21 publications

Purification of a Trypsin Inhibitor Secreted by Embryogenic Carrot Cells

Purification of a Trypsin Inhibitor Secreted by Embryogenic Carrot Cells

Isolation and Characterization of a cDNA Clone for Plant Nuclear Antigen 21D7 Associated with Cell Division

Isolation of putative embryo-specific genes using stress induction of carrot somatic embryos

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