Multiple, concentration-dependent effects of sucrose, auxins and cytokinins in explant cultures of kale and tobacco
We describe complex multiple concentration dependencies for the response of isolated pith tissues to plant biologically active substances. Kale and tobacco stem pith explants were cultured on agar media containing combinations of sucrose, cytokinin [kinetin or benzyladenine (BA)] and auxin [indole-3-acetic acid (IAA) or naphthaleneacetic acid (NAA)]. Absorption of these components by explants and their effects on explant mass, contents of soluble proteins, starch and sugars, and activity of ADP-glucose pyrophosphorylase (AGPase) were studied in relation to their concentration. Up to ten pronounced statistically significant maxima (peaks or waves) were repeatedly detected in the dose–response curves over a concentration range of several logarithmic orders. Slight maxima were observed in the corresponding absorption curves. Pronounced maxima of sucrose absorption were induced by IAA and BA, and those of NAA absorption were induced by sucrose. Both types of multiple maxima (in dose–response and absorption curves) may be due to changes in concentration of intracellular solutes (sugars, auxins and cytokinins), thereby affecting metabolic processes that act as sinks for external solutes and elicit feedback appearance of maxima in absorption curves. Good correspondence between external concentrations at which maxima of different compared curves occur in addition to statistical significance of individual maxima and repeatability of experimental results supports the conclusion that the multiple maxima exhibited are genuine. We consider it possibile that the multiple maxima are associated with endopolyploidy or mixoploidy and/or epigenomic diversity of pith cells that show different sensitivities to biologically active solutes.
KeywordsBrassica oleracea Nicotiana tabacum Absorption AGPase Endopolyploidy Epigenomic diversity Mixoploidy Soluble proteins Starch accumulation Sugars
The authors thank Prof. Per Nissen for encouragement and support, Mrs Anna Bastrová and Ing. Lenka Preclíková for technical assistance and Dr. Petr Cápal for informations concerning genomic diversification in cell cultures.
- Horák J, Landa Z, Luštinec J (1971) Production of polyploid plants from tissue cultures of Brassica oleracea L. Phyton 28:7–10Google Scholar
- Horák J, Luštinec J, Měsíček J, Kamínek M, Poláčková D (1975) Regeneration of diploid and polyploid plants from stem pith explants of diploid marrow stem kale (B. oleracea L.). Ann Bot 39:571–577Google Scholar
- Ibraheem O, Hove RM, Bradley G (2008) Sucrose assimilation and the role of sucrose transporters in plant wound response. Afr J Biotech 7:4850–4854Google Scholar
- Luštinec J (1988) Uptake and dose responses of auxin in vitro: multiphasic concentration-dependencies. In: Kutáček M, Bandurski RS, Krekule J (eds) Physiology and biochemistry of auxins in plants. Academia, Praha, pp 241–246Google Scholar
- Luštinec J, Hadačová V, Kamínek M (1974) The effect of various cytokinins and auxins on starch formation in kale and tobacco explants. In: Schreiber K, Schütte HR, Sembdner G (eds) Biochemistry and chemistry of plant growth regulators. Inst Biochem Pflanz, Halle, pp 311–313Google Scholar
- Luštinec J, Kamínek M, Hadačová V (1976) Hormonal control of starch accumulation and cell expansion in tobacco stem pith. Acta Univ Nicolai Copernici 18:117–120Google Scholar
- Murashige T, Nakano R (1966) Tissue culture as a potential tool in obtaining polyploid plants. J Hered 57:114–118Google Scholar
- Scaramuzzi F, Palubo R, De Gaetano A (1973) Interaction of sucrose and naphthaleneacetic acid on rhizogenesis and callogenesis of stem segments of Viburnum lantana L. cultured in vito in the dark and in the light, vol 277. C R Academic Science, Paris, pp 493–496Google Scholar