XM-47inhibits D14-SLR1 and D14-D53 interactions. Product of XM-47 hydrolysis, 2-methoxy-1-naphthaldehyde (2-MN), inhibits D14-SLR1 and D14-D53 interactions and restores the growth of rice tillering buds suppressed by strigolactone
Strigolactones (SLs) are carotenoid-derived plant secondary metabolites that play important roles in various aspects of plant growth and development as plant hormones, and in rhizosphere communications with symbiotic microbes and also root parasitic weeds. Therefore, sophisticated regulation of the biosynthesis, perception and functions of SLs is expected to promote symbiosis of beneficial microbes including arbuscular mycorrhizal (AM) fungi and also to retard parasitism by devastating root parasitic weeds. We have developed SL mimics with different skeletons, SL biosynthesis inhibitors acting at different biosynthetic steps, SL perception inhibitors that covalently bind to the SL receptor D14, and SL function inhibitors that bind to the serine residue at the catalytic site. In greenhouse pot tests, TIS108, an azole-type SL biosynthesis inhibitor effectively reduced numbers of attached root parasites Orobanche minor and Striga hermonthica without affecting their host plants; tomato and rice, respectively. AM colonization resulted in weak but distinctly enhanced plant resistance to pathogens. SL mimics can be used to promote AM symbiosis and to reduce the application rate of systemic-acquired resistance inducers which are generally phytotoxic to horticultural crops. (c) 2019 Society of Chemical Industry.
Title: Discovery and identification of 2-methoxy-1-naphthaldehyde as a novel strigolactone-signaling inhibitor Mashita O, Koishihara H, Fukui K, Nakamura H, Asami T Ref: J Pestic Sci, 41:71, 2016 : PubMed
Knowledge about strigolactone biosynthesis and signaling is increasing and the crystal structure of strigolactone receptor protein D14 has been resolved. Although a variety of strigolactone biosynthesis inhibitors and strigolactone agonists are known, no inhibitors of strigolactone signaling have been reported. Here, we conducted virtual screening in silico to identify chemical regulators that inhibit SL reception. We used LigandScout to analyze a pharmacophore model based on structural information about D14 protein and complex D14-D-OH (a hydrolysis product of strigolactone formed by D14). We identified a candidate compound, XM-47, and confirmed that it inhibits D14-SLR1 and D14-D53 interactions. A possible product of XM-47 hydrolysis, 2-methoxy-1-naphthaldehyde (2-MN), inhibits D14-SLR1 and D14-D53 interactions and restores the growth of rice tillering buds suppressed by strigolactone.
