Inhibition of shoot branching by new terpenoid plant hormones.
Shoot branching is a major determinant of plant architecture and is highly regulated by endogenous and environmental cues. Two classes of hormones, auxin and cytokinin, have long been known to have an important involvement in controlling shoot branching. Previous studies using a series of mutants with enhanced shoot branching suggested the existence of a third class of hormone(s) that is derived from carotenoids, but its chemical identity has been unknown. Here we show that levels of strigolactones, a group of terpenoid lactones, are significantly reduced in some of the branching mutants. Furthermore, application of strigolactones inhibits shoot branching in these mutants. Strigolactones were previously found in root exudates acting as communication chemicals with parasitic weeds and symbiotic arbuscular mycorrhizal fungi. Thus, we propose that strigolactones act as a new hormone class-or their biosynthetic precursors-in regulating above-ground plant architecture, and also have a function in underground communication with other neighbouring organisms.
Umehara
Mikihisa
M
RIKEN Plant Science Center, Tsurumi, Yokohama 230-0045, Japan.
Hanada
Atsushi
A
Yoshida
Satoko
S
Akiyama
Kohki
K
Arite
Tomotsugu
T
Takeda-Kamiya
Noriko
N
Magome
Hiroshi
H
Kamiya
Yuji
Y
Shirasu
Ken
K
Yoneyama
Koichi
K
Kyozuka
Junko
J
Yamaguchi
Shinjiro
S
D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D007783:Lactones / Q000032:analysis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D009154:Mutation; D012275:Oryza / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism / Q000469:parasitology; D010937:Plant Growth Regulators / Q000032:analysis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D018517:Plant Roots / Q000469:parasitology; D018520:Plant Shoots / Q000187:drug effects* / Q000254:growth & development*; D036226:Seedlings; D013729:Terpenes / Q000032:analysis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*
C507382:GR24 compound; D007783:Lactones; D010937:Plant Growth Regulators; D013729:Terpenes