BACKGROUND: Tuberization in potato (Solanum tuberosum L.) represents a morphogenetic transition of stolon growth to tuber formation, which is under complex environmental and endogenous regulation. In the present work, we studied the regulatory mechanisms and the role of different morphogenetic factors in a newly isolated potato mutant, which exhibited spontaneous tuberization (ST). The ST mutant was characterized in detail at morphological, physiological and biochemical levels. RESULTS: Tuberization of the ST mutant grown in the soil was photoperiod-insensitive; predominantly sessile tubers formed directly from axillary buds even under continuous light. Single-node cuttings of the ST mutant cultured in vitro frequently formed tubers or basal tuber-like swellings instead of normal shoots under conditions routinely used for shoot propagation. The tuberization response of ST cuttings under light was dependent on sucrose, the concentration of which had to exceed certain threshold that inversely correlated with irradiance. Gibberellic acid prevented tuberization of ST cuttings, but failed to restore normal shoot phenotype and caused severe malformations. Carbohydrate analysis showed increased levels of both soluble sugars and starch in ST plants, with altered carbohydrate partitioning and metabolism. Comparative proteomic analysis revealed only a few differences between ST- and wild-type plants, primary amongst which seemed to be the absence of an isoform of manganese-stabilizing protein, a key subunit of photosystem II. CONCLUSION: ST mutant exhibits complex developmental and phenotypic modifications, with features that are typical for plants strongly induced to tuberize. These changes are likely to be related to altered regulation of photosynthesis and carbohydrate metabolism rather than impaired transduction of inhibitory gibberellin or photoperiod-based signals. The effect of gibberellins on tuberization of ST mutant suggests that gibberellins inhibit tuberization downstream of the inductive effects of sucrose and other positive factors.

• MeSH
• biomasa MeSH
• DNA bakterií metabolismus   MeSH
• fotoperioda MeSH
• gibereliny farmakologie   MeSH
• hlízy rostlin účinky léků   genetika   metabolismus   účinky záření   MeSH
• inzerční mutageneze MeSH
• listy rostlin účinky léků   metabolismus   účinky záření   MeSH
• metabolismus sacharidů účinky léků   účinky záření   MeSH
• mutace genetika   MeSH
• nekódující RNA genetika   MeSH
• proteom metabolismus   MeSH
• půda MeSH
• regulace genové exprese u rostlin účinky léků   účinky záření   MeSH
• ribozomální DNA genetika   MeSH
• rostlinné geny MeSH
• sacharosa farmakologie   MeSH
• škrob metabolismus   MeSH
• Solanum tuberosum účinky léků   genetika   metabolismus   účinky záření   MeSH
• stonky rostlin účinky léků   metabolismus   účinky záření   MeSH
• světlo MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA bakterií MeSH
• gibberellic acid MeSH Prohlížeč
• gibereliny MeSH
• nekódující RNA MeSH
• proteom MeSH
• půda MeSH
• ribozomální DNA MeSH
• sacharosa MeSH
• škrob MeSH
• T-DNA MeSH Prohlížeč