Potato CONSTANS is involved in photoperiodic tuberization in a graft-transmissible manner

Plant J. 2012 May;70(4):678-90. doi: 10.1111/j.1365-313X.2012.04909.x. Epub 2012 Mar 5.


CONSTANS (CO) is involved in the photoperiodic control of plant developmental processes, including flowering in several species and seasonal growth cessation and bud set in trees. It has been proposed that CO could also affect the day-length regulation of tuber induction in Solanum tuberosum (potato), a plant of great agricultural relevance. To address this question, we examined the role of CO in potato. A potato CO-like gene, StCO, was identified and found to be highly similar to a previously reported potato gene of unknown function. Potato plants overexpressing StCO tuberized later than wild-type plants under a weakly inductive photoperiod. StCO silencing promoted tuberization under both repressive and weakly inductive photoperiods, but did not have any effect under strongly inductive short days, demonstrating that StCO represses tuberization in a photoperiod-dependent manner. The effect of StCO on tuber induction was transmitted through grafts. In addition, StCO affected the mRNA levels of StBEL5 - a tuberization promoter, the mRNA of which moves long distances in potato plants - and StFT/StSP6A, a protein highly similar to FLOWERING LOCUS T (FT), which is a key component of systemic flowering signals in other species. We also found that StFT/StSP6A transcript levels correlate with the induction of tuber formation in wild-type plants. These results show that StCO plays an important role in photoperiodic tuberization and, together with the recent demonstration that StFT/StSP6A promotes tuberization, indicate that the CO/FT module participates in controlling this process. Moreover, they support the notion that StCO is involved in the expression of long-distance regulatory signals in potato, as CO does in other species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Circadian Rhythm
  • Cloning, Molecular
  • DNA, Complementary / chemistry
  • DNA, Complementary / genetics
  • Flowers / genetics
  • Flowers / growth & development
  • Gene Expression Regulation, Developmental / radiation effects
  • Gene Expression Regulation, Plant / radiation effects
  • Molecular Sequence Data
  • Photoperiod*
  • Phylogeny
  • Plant Proteins / classification
  • Plant Proteins / genetics*
  • Plant Tubers / genetics*
  • Plant Tubers / growth & development
  • Plant Tubers / physiology
  • Plants, Genetically Modified
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Solanum tuberosum / genetics*
  • Solanum tuberosum / growth & development
  • Solanum tuberosum / physiology
  • Time Factors


  • DNA, Complementary
  • Plant Proteins

Associated data

  • GENBANK/AM888389