Does abscisic acid affect strigolactone biosynthesis

• Published in: The New phytologist 2010-07, Vol.187 (2), p.343-354
• Main Authors: López-Ráez, Juan A, Kohlen, Wouter, Charnikhova, Tatsiana, Mulder, Patrick, Undas, Anna K, Sergeant, Martin J, Verstappen, Francel, Bugg, Timothy D.H, Thompson, Andrew J, Ruyter-Spira, Carolien, Bouwmeester, Harro
• Format: Article
• Language: English
• Subjects: Abscisic acid; abscisic acid (ABA); Abscisic Acid - biosynthesis; Abscisic Acid - metabolism; Arbuscular mycorrhizas; Biosynthesis; Biosynthetic Pathways - drug effects; Carotenoids; Carotenoids - metabolism; Chromatography, Liquid; Cleavage; Deficient mutant; Dioxygenase; Enzyme Inhibitors - pharmacology; Enzymes; Exudation; Fungi; Gene expression; Gene expression regulation; Gene Expression Regulation, Plant - drug effects; Genes; Genes, Plant - genetics; Germination; Germination - drug effects; hormone regulation; Hormones; Inhibitors; Lactones - metabolism; Lycopersicon esculentum; Lycopersicon esculentum - drug effects; Lycopersicon esculentum - genetics; Lycopersicon esculentum - metabolism; Mass Spectrometry; mutants; Mutation - genetics; Orobanche - drug effects; Orobanche - growth & development; Orobanche - metabolism; Parasitic plants; Phosphates - deficiency; Phosphates - metabolism; Phytohormones; Plant Exudates - metabolism; Plant growth substances; Plant hormones; Plant roots; Plant Roots - drug effects; Plant Roots - metabolism; Plant Shoots - metabolism; Plants; Reverse Transcriptase Polymerase Chain Reaction; Rhizosphere; Root exudates; Seeds; Starvation; strigolactones; tomato; Tomatoes
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2010.03291.x

Strigolactones are considered a novel class of plant hormones that, in addition to their endogenous signalling function, are exuded into the rhizosphere acting as a signal to stimulate hyphal branching of arbuscular mycorrhizal (AM) fungi and germination of root parasitic plant seeds. Considering the importance of the strigolactones and their biosynthetic origin (from carotenoids), we investigated the relationship with the plant hormone abscisic acid (ABA). Strigolactone production and ABA content in the presence of specific inhibitors of oxidative carotenoid cleavage enzymes and in several tomato ABA-deficient mutants were analysed by LC-MS/MS. In addition, the expression of two genes involved in strigolactone biosynthesis was studied. The carotenoid cleavage dioxygenase (CCD) inhibitor D2 reduced strigolactone but not ABA content of roots. However, in abamineSG-treated plants, an inhibitor of 9-cis-epoxycarotenoid dioxygenase (NCED), and the ABA mutants notabilis, sitiens and flacca, ABA and strigolactones were greatly reduced. The reduction in strigolactone production correlated with the downregulation of LeCCD7 and LeCCD8 genes in all three mutants. The results show a correlation between ABA levels and strigolactone production, and suggest a role for ABA in the regulation of strigolactone biosynthesis.