Figures & data
Fig. 1. Effect of IOEP on root growth in Arabidopsis seedlings.
Note: (A) IAA biosynthesis pathways and intermediates. (B) Synthesis of IOEP. a, diethyl phosphonoacetic acid, acetic anhydride in AcOH at 110 °C, 5 h, 37% yield; b, (CH3)3SiBr in MeCN at r.t., 40 h, 73% yield. Wild-type Arabidopsis thaliana (WT; ecotype Col-0) seeds were sterilized and grown for 10 d on half-strength MS agar medium containing 1% sucrose and 0.8% agar, pH 5.8 supplemented with 30 µm IOEP or 30 nm IAA. The seedlings were grown under continuous light at 22 °C. Scale bars: 1 cm (C), 2 mm (D). (E) WT seedlings were grown for 8 d on half-strength MS agar medium supplemented with 3 µm IOEP or 1 nm IAA under continuous light at 22 °C. Primary root length of the seedlings was analyzed with ImageJ software (NIH, MD). Data represent means ± SE (n = 13–15).
Fig. 2. Effect of IOEP on endogenous IAA Levels in Arabidopsis seedlings.
Note: WT seeds were sterilized and grown on half-strength MS agar medium for 6 d. The seedlings were transferred to half-strength MS liquid medium containing 1% sucrose, pH 5.8, cultured for 1 d, and then treated with IOEP for 3 h. Endogenous IAA levels were analyzed as previously described.Citation8) Data represent means ± SE (n = 3).
Fig. 3. qRT-PCR analysis of Aux/IAA1 and Aux/IAA19 gene expression in response to treatment with IOEP and IAA biosynthesis intermediates.
Note: WT seeds were sterilized and grown for 7 d in half-strength MS liquid medium. The seedlings were pretreated with 60 µm AOPP or 60 µm IOEP for 2 h and then treated with 10 µm IAA or its biosynthesis intermediate for 1 h. qRT-PCR analysis was done as described previously.Citation8) Data represent means ± SE (n = 3). Statistically significant differences relative to mock treatment are indicated by asterisks (student’s t-test, *p < 0.1).
