Effects of Triazole Derivatives on Strigolactone Levels and Growth Retardation in Rice

Shinsaku Ito,Hiroki Hayase,Atsushi Hanada,Shinjiro Yamaguchi,Nobutaka Kitahata,Tadao Asami,Mikihisa Umehara,Yin-Won Lee

doi:10.1371/journal.pone.0021723

Shinsaku Ito, Hiroki Hayase + Show 6 more

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https://doi.org/10.1371/journal.pone.0021723

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Abstract

We previously discovered a lead compound for strigolactone (SL) biosynthesis inhibitors, TIS13 (2,2-dimethyl-7-phenoxy-4-(1H-1,2,4-triazol-1-yl)heptan-3-ol). Here, we carried out a structure-activity relationship study of TIS13 to discover more potent and specific SL biosynthesis inhibitor because TIS13 has a severe side effect at high concentrations, including retardation of the growth of rice seedlings. TIS108, a new TIS13 derivative, was found to be a more specific SL biosynthesis inhibitor than TIS13. Treatment of rice seedlings with TIS108 reduced SL levels in both roots and root exudates in a concentration-dependent manner and did not reduce plant height. In addition, root exudates of TIS108-treated rice seedlings stimulated Striga germination less than those of control plants. These results suggest that TIS108 has a potential to be applied in the control of root parasitic weeds germination.

Highlights

Strigolactones (SLs) are a group of terpenoid lactones that have been found in root exudates of various plant species and were first identified as seed germination stimulants of root parasitic weeds such as Orobanche and Striga [1]
Concluding remarks To develop more potent and specific SL biosynthesis inhibitors than TIS13, we carried out a structure-activity relationship study and found TIS108 as the most potent and specific SL biosynthesis inhibitor among the chemicals synthesized in our laboratory
As root parasitic weeds are responsible for large-scale crop devastation all over the world, TIS108 can be a new tool for controlling parasitic weeds by the application as root parasitic weed control agent

Summary

Introduction

Strigolactones (SLs) are a group of terpenoid lactones that have been found in root exudates of various plant species and were first identified as seed germination stimulants of root parasitic weeds such as Orobanche and Striga [1]. SLs induce hyphal branching in arbuscular mycorrhizal fungi that form symbiotic associations with the roots of more than 80% of land plants [2]. Two groups reported that SLs or their metabolites inhibit shoot branching [3,4]. Root parasitic weeds are considered as harmful plants in subSaharan Africa, the Middle East and Asia that parasitize the roots of host plants. It was reported that around 300 million people are affected by Striga in Africa with a loss of $US 7 to 10 billion [8]. Many approaches to control the parasitic weeds have been explored, useful solutions have not been discovered

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