Gomez-Roldan Victoria, Fermas Soraya, Brewer Philip B, Puech-Pagès Virginie, Dun Elizabeth A, Pillot Jean-Paul, Letisse Fabien, Matusova Radoslava, Danoun Saida, Portais Jean-Charles, Bouwmeester Harro, Bécard Guillaume, Beveridge Christine A, Rameau Catherine, Rochange Soizic F
Université de Toulouse, UPS, CNRS, Surface Cellulaire et Signalisation chez les Végétaux, 24 chemin de Borde Rouge, F-31326 Castanet-Tolosan, France.
Nature. 2008 Sep 11;455(7210):189-94. doi: 10.1038/nature07271.
A carotenoid-derived hormonal signal that inhibits shoot branching in plants has long escaped identification. Strigolactones are compounds thought to be derived from carotenoids and are known to trigger the germination of parasitic plant seeds and stimulate symbiotic fungi. Here we present evidence that carotenoid cleavage dioxygenase 8 shoot branching mutants of pea are strigolactone deficient and that strigolactone application restores the wild-type branching phenotype to ccd8 mutants. Moreover, we show that other branching mutants previously characterized as lacking a response to the branching inhibition signal also lack strigolactone response, and are not deficient in strigolactones. These responses are conserved in Arabidopsis. In agreement with the expected properties of the hormonal signal, exogenous strigolactone can be transported in shoots and act at low concentrations. We suggest that endogenous strigolactones or related compounds inhibit shoot branching in plants. Furthermore, ccd8 mutants demonstrate the diverse effects of strigolactones in shoot branching, mycorrhizal symbiosis and parasitic weed interaction.
一种抑制植物侧枝生长的类胡萝卜素衍生激素信号长期以来一直未被识别。独脚金内酯是一类被认为源自类胡萝卜素的化合物，已知它能触发寄生植物种子的萌发并刺激共生真菌。在此，我们提供证据表明，豌豆类胡萝卜素裂解双加氧酶8侧枝生长突变体缺乏独脚金内酯，而施加独脚金内酯可使ccd8突变体恢复野生型侧枝生长表型。此外，我们表明，其他先前被鉴定为对侧枝生长抑制信号无响应的侧枝生长突变体也缺乏独脚金内酯响应，且并非独脚金内酯缺乏。这些响应在拟南芥中是保守的。与激素信号的预期特性一致，外源独脚金内酯可在茎中运输并在低浓度下起作用。我们认为，内源性独脚金内酯或相关化合物抑制植物的侧枝生长。此外，ccd8突变体证明了独脚金内酯在侧枝生长、菌根共生和寄生杂草相互作用中的多种作用。
