Fig. 2: SRF3 regulates early root growth response and undergoes degradation upon low iron levels.
a Maximum intensity projection of confocal images of root tips of 5 day old seedlings expressing pSRF3::mCITRINE-NLS-mCITRINE and pSRF3::SRF3-mCITRINE in Col-0. This pattern has been observed at least hundreds of times. Scale bars, 100 μm. b Graph showing time-lapse analysis for 12 h of the root length of WT and srf3-3 under sufficient (+Fe) and low (–Fe) iron media [error bars indicate standard error of the mean (SEM); Asterix: first timepoint with significant difference between WT in +Fe and –Fe conditions according to a mixed effect model (p < 0.05)] and the related quantification including the srf3-2 mutant [ANOVA with post hoc Tukey test; Letters: statistical differences (p < 0.05)]. c Confocal images of root epidermal cells in the elongation zone of 5 day old seedlings expressing p35s::eGFP-Lti6b/col-0, pUBQ10::SRF3WT-mCITRINE/col-0, pUBQ10::SRF3ΔExtraC-mCITRINE/col-0, pUBQ10::SRF3KD-mCITRINE/col-0 under iron sufficient (+Fe, 2 h) and low iron levels (–FeFZ 100 μM, 2 h) and the related quantification [two-ways student test (p < 0.05), n.s.: non-significant]. Scale bars 10 μm. Note that the pictures have been pseudo-colored in green fire blue to emphasize changes in fluorescence intensity. d Graph representing the fluorescence intensity in the root tip of the indicated protein fusions under sufficient (+Fe) and low (–Fe) iron media [error bars indicate SEM; Asterix: first timepoint with significant difference between +Fe and –Fe for pUBQ10::SRF3-mCITRINE according to a mixed effect model (p < 0.05)]. e Graph showing time-lapse analysis for 12 h of the root length of WT and SRF3WT-OX under sufficient (+Fe) and low (–Fe) iron media [error bars indicate SEM] and related quantification including SRF3ΔExtraC and SRF3KD [ANOVA with post hoc Fisher test; Letters: statistical differences (p < 0.05)].
