Effects of strigolactone-biosynthesis inhibitor TIS108 onArabidopsis

Abstract

Strigolactones (SLs) are terpenoid lactones produced in many plant species and have various functions: germination stimulants of root parasitic weeds, root-derived signals that induce hyphal branching in arbuscular mycorrhizal fungi, and a plant hormone that inhibits shoot branching and regulates root morphology. [1][2][3][4] In the past, several branching mutants have been identified as SL biosynthesis and signaling mutants. To date, it is known that the biosynthesis of SLs is controlled by one b-carotene isomerase (D27), two carotenoid cleavage dioxygenases, CCD7 (MAX3, RMS5 D17/ HTD1, DAD3) and CCD8 (MAX4, RMS1, D10, DAD1) and one cytochrome P450 monooxygenase (MAX1). [5][6][7] More recently, Alder et al. reported that three enzymes, D27, CCD7 and CCD8, produce an SL-like chemical named carlactone from b-carotene in vitro and proposed a SL-biosynthesis pathway. 7 However, the enzymatic function of MAX1 has not been uncovered.As described above, at least one step of SL biosynthesis is thought to be mediated by one cytochrome P450 enzyme, 8 and therefore P450 inhibitors may inhibit SL biosynthesis in Arabidopsis. Previously, we chose triazole derivatives as these have been shown to act as efficient inhibitors of P450 monooxygenase and reported two SL-biosynthesis inhibitors, 2,2-dimethyl-7-phenoxy-4-(1H-1,2,4-triazol-1-yl)heptan-3-ol (TIS13) 9 and 6-phenoxy-1-phenyl-2-(1H-1,2,4-triazol-1-yl) hexan-1-one (TIS108) 10 ( Fig. 1A). Although TIS13 inhibits the production of epi-5DS, which is a major SL, in rice, TIS13-treated plants show a severe dwarf phenotype which does not recover following the application of SL; this suggests the possibility that TIS13 inhibits the biosynthesis of other plant hormones such as gibberellin (GA) and/or brassinosteroid (BR). 9 To develop specific SL-biosynthesis inhibitors, a structure-activity relationship study on TIS13 derivatives tiS108 is a triazole-type strigolactone (SL)-biosynthesis inhibitor that reduces the level of 2'-epi-5-deoxystrigol (epi-5DS) in rice. here we report the effects of tiS108 on Arabidopsis. treatment of tiS108 increased the number of branches and repressed root hair elongation as was observed in SL-deficient mutants, and co-application of Gr24, a synthetic SL analog, recovered the tiS108-induced phenotype to that of wild-type. in addition, MaX3 and MaX4 genes in the SL-biosynthesis pathway were upregulated in tiS108-treated Arabidopsis, probably due to feedback regulation caused by SL deficiency. these results indicate that tiS108 is an effective tool for regulating SL production in Arabidopsis. Keywords: plant hormone, strigolactone, plant growth regulator, biosynthesis inhibitor, Arabidopsis was performed by estimating the level of epi-5DS and growth retardation in rice, which led to the identification of a specific SL-biosynthesis inhibitor, TIS108 10 ( Fig. 1). However, it is unclear whether TIS108 inhibits the production of SLs in Arabidopsis. In this study, to identify the effect of TIS108 on SL function in Arabidopsis, we examined the morphological...

Transcriptome analysis of Phelipanche aegyptiaca seed germination mechanisms stimulated by fluridone, TIS108, and GR24

“…Researchers previously reported that TIS108, a triazole-type SL-biosynthesis inhibitor, reduced SL concentrations in Arabidopsis and rice [ 17 , 53 ]. Those authors suggested that the germination of root parasitic weeds could be reduced by treating the host plants with TIS108.…”

Strigolactones are common regulators in induction of stomatal closure in planta

“…TIS108 was reported as a novel SL-biosynthetic inhibitor which could reduce the level of SLs in various plant species. [24][25][26] TIS108-treated Arabidopsis and rice exhibited SL-deficient phenotypes such as more branches and root hair inhibition. 25,26 We next investigated the effect of TIS108 on stomatal closure.…”

“…[24][25][26] TIS108-treated Arabidopsis and rice exhibited SL-deficient phenotypes such as more branches and root hair inhibition. 25,26 We next investigated the effect of TIS108 on stomatal closure. Unexpectedly, the exogenous application of TIS108 at different concentrations exerted no effect on stomatal apertures ( Fig.…”

“…It was reported that TIS108 specifically reduced the level of 2'-epi-5-deoxystrigol (epi-5DS). [24][25][26] However, it was suggested that unknown molecules in guard cells such as SL-like compound(s) or SL intermediates, rather than epi-5DS, were implicated in the stomatal movement. 22,27 Therefore it is possible that TIS108 could not inhibit the biosynthesis of those molecules in guard cells.…”

Chemical regulators of plant hormones and their applications in basic research and agriculture*

“…To date, chemical inhibition of endogenous SL by targeting these biosynthesis enzymes has been useful for investigating SL biosynthesis and extending our knowledge of the biological roles of SLs in plants [356]. Several chemicals have been reported to inhibit SL biosynthesis, including abamine (60, Figure 4(A)) targeting CCD [357], TIS13 (186, Figure 9(A)) and its derivative TIS108 (187, Figure 9(A)), which might target P450 [358][359][360], and tebuconazole (188, Figure 9(A)) targeting P450 [361], although not all of these are specific inhibitors of SL biosynthesis. Sergeant et al [362] developed a series of new inhibitors of CCD based on abamine and found that several of these could inhibit CCDs and promotion of branching, suggesting that these chemicals could be SL biosynthesis inhibitors.…”