SlCCD7 controls strigolactone biosynthesis, shoot branching and mycorrhiza-induced apocarotenoid formation in tomato.

J.T. Vogel, M.H. Walter, P. Giavalisco, A. Lytovchenko, W. Kohlen, T. Charnikhova, A.J. Simkin, C. Goulet, D. Strack, H.J. Bouwmeester, A.R. Fernie, H.J. Klee

Research output: Contribution to journalArticleAcademicpeer-review

214 Citations (Scopus)

Abstract

The regulation of shoot branching is an essential determinant of plant architecture, integrating multiple external and internal signals. One of the signaling pathways regulating branching involves the MAX (more axillary branches) genes. Two of the genes within this pathway, MAX3/CCD7 and MAX4/CCD8, encode carotenoid cleavage enzymes involved in generating a branch-inhibiting hormone, recently identified as strigolactone. Here, we report the cloning of SlCCD7 from tomato. As in other species, SlCCD7 encodes an enzyme capable of cleaving cyclic and acyclic carotenoids. However, the SlCCD7 protein has 30 additional amino acids of unknown function at its C terminus. Tomato plants expressing a SlCCD7 antisense construct display greatly increased branching. To reveal the underlying changes of this strong physiological phenotype, a metabolomic screen was conducted. With the exception of a reduction of stem amino acid content in the transgenic lines, no major changes were observed. In contrast, targeted analysis of the same plants revealed significantly decreased levels of strigolactone. There were no significant changes in root carotenoids, indicating that relatively little substrate is required to produce the bioactive strigolactones. The germination rate of Orobanche ramosa seeds was reduced by up to 90% on application of extract from the SlCCD7 antisense lines, compared with the wild type. Additionally, upon mycorrhizal colonization, C13 cyclohexenone and C14 mycorradicin apocarotenoid levels were greatly reduced in the roots of the antisense lines, implicating SlCCD7 in their biosynthesis. This work demonstrates the diverse roles of MAX3/CCD7 in strigolactone production, shoot branching, source–sink interactions and production of arbuscular mycorrhiza-induced apocarotenoids.
Original languageEnglish
Pages (from-to)300-311
JournalThe Plant Journal
Volume61
Issue number2
DOIs
Publication statusPublished - 2010

Keywords

  • carotenoid cleavage dioxygenase
  • root-derived signal
  • striga-lutea lour
  • germination stimulants
  • liquid-chromatography
  • plant architecture
  • yellow pigment
  • orobanche spp.
  • arabidopsis
  • genes

Fingerprint

Dive into the research topics of 'SlCCD7 controls strigolactone biosynthesis, shoot branching and mycorrhiza-induced apocarotenoid formation in tomato.'. Together they form a unique fingerprint.

Cite this