title: Light is a positive regulator of strigolactone levels in tomato roots.
abstract: Strigolactones (SLs) or closely related molecules were recently identified as phytohormones, acting as long-distance branching factors that suppress growth of pre-formed axillary buds in the shoot. The SL signaling pathways and light appear to be connected, as SLs were shown to induce light-regulated pathways and to mimic light-adapted plant growth. However, it is not yet clear how light affects SL levels. Here, we examined the effect of different light intensities on SL levels in tomato roots. The results show that light intensity, above a certain threshold, is a positive regulator of SL levels and of Sl-CCD7 transcription; Sl-CCD7 is involved in SLs biosynthesis in tomato. Moreover, SL accumulation in plant roots is shown to be a time-dependent process. At least some of the similar effects of light and SLs on plant responses might result from a positive effect of light on SL levels.
authors.affiliation: Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, PO Box 6, Bet Dagan 50250, Israel.
authors.forename: Hinanit
authors.initials: H
authors.lastname: Koltai
authors.forename: Maja
authors.initials: M
authors.lastname: Cohen
authors.forename: Ori
authors.initials: O
authors.lastname: Chesin
authors.forename: Einav
authors.initials: E
authors.lastname: Mayzlish-Gati
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bécard
authors.forename: Virginie
authors.initials: V
authors.lastname: Puech
authors.forename: Bruria
authors.initials: B
authors.lastname: Ben Dor
authors.forename: Natalie
authors.initials: N
authors.lastname: Resnick
authors.forename: Smadar
authors.initials: S
authors.lastname: Wininger
authors.forename: Yoram
authors.initials: Y
authors.lastname: Kapulnik
mesh_terms: D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D007783:Lactones / Q000378:metabolism / Q000528:radiation effects*; D008027:Light; D018551:Solanum lycopersicum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D010937:Plant Growth Regulators / Q000378:metabolism / Q000528:radiation effects; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000528:radiation effects; D015398:Signal Transduction / Q000528:radiation effects; D013997:Time Factors
chemical_list: D007783:Lactones; D010937:Plant Growth Regulators; D010940:Plant Proteins