Project description:For expression profiling analyses of early stages of tuber induction, plants of Solanum tuberosum ssp andigena (7540) were used. This wild subspecies is strictly dependent on photoperiod for tuberisation, such that short days (SD) inductive conditions are required in order to trigger tuber induction in the stolons. Andigena plants were grown in the greenhouse under LD non-inductive conditions until a 10-leaf stage. They were subsequently transferred to inductive SD conditions (8 h light/16 h dark), and sampled at 0, 2, 4, 6 and 8 days after transfer to SDs. Tuber swelling was visible approximately 6-8 days after transfer to inductive conditions. The apical region of the stolons (2 cm) was collected one hour before the beginning of the light period.
Project description:For expression profiling analyses of early stages of tuber induction, plants of Solanum tuberosum ssp andigena (7540) were used. This wild subspecies is strictly dependent on photoperiod for tuberisation, such that short days (SD) inductive conditions are required in order to trigger tuber induction in the stolons. Andigena plants were grown in the greenhouse under LD non-inductive conditions until a 10-leaf stage. They were subsequently transferred to inductive SD conditions (8 h light/16 h dark), and sampled at 0, 2, 4, 6 and 8 days after transfer to SDs. Tuber swelling was visible approximately 6-8 days after transfer to inductive conditions. The apical region of the stolons (2 cm) was collected one hour before the beginning of the light period. All collected stolons (LD; and 2d, 4d, 6d and 8d under SD) were processed as described. Hybridization scheme with a loop design was applied to compare one sample against the rest of the samples in the induction time course.
Project description:Summary StSP6A is a protein with sequence homology to the Arabidopsis FLOWERING LOCUS T (FT). FT is a main component of the long range flowering promoting signal or florigen that induces photoperiodic flowering under long days (LDs). In potato, short days (SDs) promote tuber induction, and wild subspecies like Solanum tuberosum ssp andigena (wild type line 7540) are strictly dependent on SDs to tuberize. StSP6A transcription is induced in leaves and stolons at early stages upon transfer to SD inductive conditions, priotr to visible solon swelling. Transgenic andigena lines over-expressing the StSP6A gene under the control of the 35S promoter are able to tuberize under LD non-inductive conditions, whereas silencing of this gene by means of an specific RNAi construct are strongly delayed in tuber induction in SD inductive conditions. This data indicate that StSP6A plays a central role in the control of tuber induction.
Project description:Recent advances have defined some of the components of photoperiodic signalling that lead to tuberisation in potato including orthologues of FLOWERING LOCUS T (StSP6A) and CYCLING DOF FACTOR (StCDF1). The aim of the current study is to investigate the molecular basis of permissive tuber initiation under long days in Solanum tuberosum Neo-Tuberosum by comparative analysis with an obligate short day Solanum tuberosum ssp. Andigena accession. We show that the Neo-Tuberosum accession, but not the Andigena, contains alleles that encode StCDF1 proteins modified in the C-terminal region, likely to evade long day inhibition of StSP6A expression. We also identify an allele of StSP6A from the Neo-Tuberosum accession, absent in the Andigena, which is expressed under long days. Other leaf transcripts and metabolites that show different abundances in tuberising and non-tuberising samples were identified adding detail to tuberisation-associated processes. Overall, the data presented in this study highlight the subtle interplay between components of the clock-CONSTANS-StSP6A axis which collectively may interact to fine-tune the timing of tuberisation.
Project description:Summary StSP6A is a protein with sequence homology to the Arabidopsis FLOWERING LOCUS T (FT). FT is a main component of the long range flowering promoting signal or florigen that induces photoperiodic flowering under long days (LDs). In potato, short days (SDs) promote tuber induction, and wild subspecies like Solanum tuberosum ssp andigena (wild type line 7540) are strictly dependent on SDs to tuberize. StSP6A transcription is induced in leaves and stolons at early stages upon transfer to SD inductive conditions, priotr to visible solon swelling. Transgenic andigena lines over-expressing the StSP6A gene under the control of the 35S promoter are able to tuberize under LD non-inductive conditions, whereas silencing of this gene by means of an specific RNAi construct are strongly delayed in tuber induction in SD inductive conditions. This data indicate that StSP6A plays a central role in the control of tuber induction. For each sample of the two comparisons (35S-StSP6A versus Wild Type and StSP6A-RNAi versus Wild Type) two biological replicates were prepared. In the case of 35S-StSP6A and StSP6A-RNAi each replicate was composed by a pool of several transgenic lines.