TY  - JOUR
AU  - Ćosić, Tatjana
AU  - Motyka, Vaclav
AU  - Raspor, Martin
AU  - Savic, Jelena
AU  - Cingel, Aleksandar
AU  - Vinterhalter, Branka
AU  - Vinterhalter, Dragan
AU  - Travnickova, Alena
AU  - Dobrev, Petre I.
AU  - Bohanec, Borut
AU  - Ninković, Slavica
PY  - 2015
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1956
AB  - Kohlrabi (Brassica oleracea var. gongylodes) cultivars Vienna Purple
   (VP) and Vienna White (VW) were tested for their ability of de novo
   organogenesis in vitro. Root, cotyledon, hypocotyl explants and intact
   seedlings were cultivated on Murashige and Skoog (MS) media supplemented
   with different cytokinins: benzyladenine (BA), thidiazuron (TDZ), trans-
   or cis-zeatin. All tested cytokinins, including cis-zeatin, induced
   shoot regeneration from hypocotyl explants and intact seedlings, with
   seedlings being most successful for regeneration efficiency and
   viability of regenerated shoots in both cultivars. The highest frequency
   of shoot regeneration was achieved on MS with BA (60 \%) or TDZ (50 \%)
   for VP; and with BA (50 \%), TDZ (47.5 \%) or transZ (37.5 \%) for VW.
   Measurements of the endogenous cytokinin and indole-3-acetic acid (IAA)
   contents in both hypocotyl explants and seedlings with regenerated
   shoots (HRSs and SRSs) suggested that the observed differences in
   organogenic response between these two types of explants were related to
   their cytokinin and IAA contents. HRSs generally exhibited elevated
   amounts of total cytokinins, while SRSs displayed a higher IAA/bioactive
   cytokinins ratio. Shoots regenerated from seedlings were further
   successfully multiplicated on a medium supplemented with BA (0.5 mg
   L-1). The rooting potential of multiplicated shoots was tested on media
   supplemented with 2 or 4 mg L-1 indole-3-butyric acid (IBA), with the
   higher concentration of IBA leading to more efficient rooting. Rooted
   plantlets were successfully planted into soil and flow cytometric
   analysis did not reveal ploidy variations, indicating that the described
   protocol is fast and efficient for kohlrabi regeneration.
T2  - Plant Cell Tissue and Organ Culture
T1  - In vitro shoot organogenesis and comparative analysis of endogenous
 phytohormones in kohlrabi (Brassica oleracea var. gongylodes): effects
 of genotype, explant type and applied cytokinins
IS  - 3
VL  - 121
DO  - 10.1007/s11240-015-0742-2
SP  - 741
EP  - 760
ER  - 

@article{
author = "Ćosić, Tatjana and Motyka, Vaclav and Raspor, Martin and Savic, Jelena and Cingel, Aleksandar and Vinterhalter, Branka and Vinterhalter, Dragan and Travnickova, Alena and Dobrev, Petre I. and Bohanec, Borut and Ninković, Slavica",
year = "2015",
abstract = "Kohlrabi (Brassica oleracea var. gongylodes) cultivars Vienna Purple
   (VP) and Vienna White (VW) were tested for their ability of de novo
   organogenesis in vitro. Root, cotyledon, hypocotyl explants and intact
   seedlings were cultivated on Murashige and Skoog (MS) media supplemented
   with different cytokinins: benzyladenine (BA), thidiazuron (TDZ), trans-
   or cis-zeatin. All tested cytokinins, including cis-zeatin, induced
   shoot regeneration from hypocotyl explants and intact seedlings, with
   seedlings being most successful for regeneration efficiency and
   viability of regenerated shoots in both cultivars. The highest frequency
   of shoot regeneration was achieved on MS with BA (60 \%) or TDZ (50 \%)
   for VP; and with BA (50 \%), TDZ (47.5 \%) or transZ (37.5 \%) for VW.
   Measurements of the endogenous cytokinin and indole-3-acetic acid (IAA)
   contents in both hypocotyl explants and seedlings with regenerated
   shoots (HRSs and SRSs) suggested that the observed differences in
   organogenic response between these two types of explants were related to
   their cytokinin and IAA contents. HRSs generally exhibited elevated
   amounts of total cytokinins, while SRSs displayed a higher IAA/bioactive
   cytokinins ratio. Shoots regenerated from seedlings were further
   successfully multiplicated on a medium supplemented with BA (0.5 mg
   L-1). The rooting potential of multiplicated shoots was tested on media
   supplemented with 2 or 4 mg L-1 indole-3-butyric acid (IBA), with the
   higher concentration of IBA leading to more efficient rooting. Rooted
   plantlets were successfully planted into soil and flow cytometric
   analysis did not reveal ploidy variations, indicating that the described
   protocol is fast and efficient for kohlrabi regeneration.",
journal = "Plant Cell Tissue and Organ Culture",
title = "In vitro shoot organogenesis and comparative analysis of endogenous
 phytohormones in kohlrabi (Brassica oleracea var. gongylodes): effects
 of genotype, explant type and applied cytokinins",
number = "3",
volume = "121",
doi = "10.1007/s11240-015-0742-2",
pages = "741-760"
}

Ćosić, T., Motyka, V., Raspor, M., Savic, J., Cingel, A., Vinterhalter, B., Vinterhalter, D., Travnickova, A., Dobrev, P. I., Bohanec, B.,& Ninković, S.. (2015). In vitro shoot organogenesis and comparative analysis of endogenous
 phytohormones in kohlrabi (Brassica oleracea var. gongylodes): effects
 of genotype, explant type and applied cytokinins. in Plant Cell Tissue and Organ Culture, 121(3), 741-760.
https://doi.org/10.1007/s11240-015-0742-2

Ćosić T, Motyka V, Raspor M, Savic J, Cingel A, Vinterhalter B, Vinterhalter D, Travnickova A, Dobrev PI, Bohanec B, Ninković S. In vitro shoot organogenesis and comparative analysis of endogenous
 phytohormones in kohlrabi (Brassica oleracea var. gongylodes): effects
 of genotype, explant type and applied cytokinins. in Plant Cell Tissue and Organ Culture. 2015;121(3):741-760.
doi:10.1007/s11240-015-0742-2 .

Ćosić, Tatjana, Motyka, Vaclav, Raspor, Martin, Savic, Jelena, Cingel, Aleksandar, Vinterhalter, Branka, Vinterhalter, Dragan, Travnickova, Alena, Dobrev, Petre I., Bohanec, Borut, Ninković, Slavica, "In vitro shoot organogenesis and comparative analysis of endogenous
 phytohormones in kohlrabi (Brassica oleracea var. gongylodes): effects
 of genotype, explant type and applied cytokinins" in Plant Cell Tissue and Organ Culture, 121, no. 3 (2015):741-760,
https://doi.org/10.1007/s11240-015-0742-2 . .

TY  - JOUR
AU  - Raspor, Martin
AU  - Motyka, Vaclav
AU  - Zizkova, Eva
AU  - Dobrev, Petre I
AU  - Travnickova, Alena
AU  - Zdravković-Korać, Snežana
AU  - Simonović, Ana
AU  - Ninković, Slavica
AU  - Dragicević, Ivana C
PY  - 2012
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1147
AB  - Genes encoding cytokinin oxidase/dehydrogenase (CKX) enzymes have been used lately to study cytokinin homeostasis in a variety of plant species. In this study AtCKX2-overexpressing potato plants were engineered and grown in vitro as a model system to investigate the effects of altered cytokinin levels on tuber formation and tuber size. Protein extracts from shoots and roots of transformed potato plants exhibited higher CKX activity compared to control plants. Total endogenous cytokinin levels were generally not decreased in AtCKX2 overexpressors. However, levels of bioactive cytokinins were markedly lowered, which was accompanied by increased levels of O- and N-glucosides in some transgenic lines. The AtCKX2-overexpressing plants displayed reduced shoot growth but other symptoms of the "cytokinin deficiency syndrome" were not recorded. The transgenic plants were able to produce tubers in noninducing conditions. In inducing conditions they developed larger tubers than control. Tubers were also formed on a greater portion of the analyzed AtCKX2 plants, but with a lower number of tubers per plant compared to control. Taken together, our data suggest that cytokinins cannot be regarded simply as positive or negative regulators of tuberization, at least in vitro. Interactions with other plant hormones that play an important role in control of tuberization, such as gibberellins, should be further studied in detail.
T2  - Journal of Plant Growth Regulation
T1  - Cytokinin Profiles of AtCKX2-Overexpressing Potato Plants and the Impact of Altered Cytokinin Homeostasis on Tuberization In Vitro
IS  - 3
VL  - 31
SP  - 85
EP  - 470
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1147
ER  - 

@article{
author = "Raspor, Martin and Motyka, Vaclav and Zizkova, Eva and Dobrev, Petre I and Travnickova, Alena and Zdravković-Korać, Snežana and Simonović, Ana and Ninković, Slavica and Dragicević, Ivana C",
year = "2012",
abstract = "Genes encoding cytokinin oxidase/dehydrogenase (CKX) enzymes have been used lately to study cytokinin homeostasis in a variety of plant species. In this study AtCKX2-overexpressing potato plants were engineered and grown in vitro as a model system to investigate the effects of altered cytokinin levels on tuber formation and tuber size. Protein extracts from shoots and roots of transformed potato plants exhibited higher CKX activity compared to control plants. Total endogenous cytokinin levels were generally not decreased in AtCKX2 overexpressors. However, levels of bioactive cytokinins were markedly lowered, which was accompanied by increased levels of O- and N-glucosides in some transgenic lines. The AtCKX2-overexpressing plants displayed reduced shoot growth but other symptoms of the "cytokinin deficiency syndrome" were not recorded. The transgenic plants were able to produce tubers in noninducing conditions. In inducing conditions they developed larger tubers than control. Tubers were also formed on a greater portion of the analyzed AtCKX2 plants, but with a lower number of tubers per plant compared to control. Taken together, our data suggest that cytokinins cannot be regarded simply as positive or negative regulators of tuberization, at least in vitro. Interactions with other plant hormones that play an important role in control of tuberization, such as gibberellins, should be further studied in detail.",
journal = "Journal of Plant Growth Regulation",
title = "Cytokinin Profiles of AtCKX2-Overexpressing Potato Plants and the Impact of Altered Cytokinin Homeostasis on Tuberization In Vitro",
number = "3",
volume = "31",
pages = "85-470",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1147"
}

Raspor, M., Motyka, V., Zizkova, E., Dobrev, P. I., Travnickova, A., Zdravković-Korać, S., Simonović, A., Ninković, S.,& Dragicević, I. C.. (2012). Cytokinin Profiles of AtCKX2-Overexpressing Potato Plants and the Impact of Altered Cytokinin Homeostasis on Tuberization In Vitro. in Journal of Plant Growth Regulation, 31(3), 85-470.
https://hdl.handle.net/21.15107/rcub_ibiss_1147

Raspor M, Motyka V, Zizkova E, Dobrev PI, Travnickova A, Zdravković-Korać S, Simonović A, Ninković S, Dragicević IC. Cytokinin Profiles of AtCKX2-Overexpressing Potato Plants and the Impact of Altered Cytokinin Homeostasis on Tuberization In Vitro. in Journal of Plant Growth Regulation. 2012;31(3):85-470.
https://hdl.handle.net/21.15107/rcub_ibiss_1147 .

Raspor, Martin, Motyka, Vaclav, Zizkova, Eva, Dobrev, Petre I, Travnickova, Alena, Zdravković-Korać, Snežana, Simonović, Ana, Ninković, Slavica, Dragicević, Ivana C, "Cytokinin Profiles of AtCKX2-Overexpressing Potato Plants and the Impact of Altered Cytokinin Homeostasis on Tuberization In Vitro" in Journal of Plant Growth Regulation, 31, no. 3 (2012):85-470,
https://hdl.handle.net/21.15107/rcub_ibiss_1147 .