Figure 2.

Heat stress inhibits phloem unloading in the root tips. (A) Comparison of the phloem unloading in the root of pSUC2::GFP-expressing 5-day-old seedlings at 48 h after being transferred to 22 °C and 30 °C. Scale bars = 100 μm. (B) Quantification of fluorescence intensity in an area of 50 × 40 µm² (ROI1, 50 µm away from quiescent center (QC) in the central root meristem). (C) Quantification of fluorescence intensity in an area of 50 × 40 µm² (ROI2, 300 µm away from QC in the stele). (D) Quantification the unloading capability from the phloem into the meristem by the ratio of GFP fluorescence intensity of an ROI1 relative to an ROI2. In the box plots (B–D), the boxes indicate the first and third quartiles, and the whiskers indicate the minimum and maximum values. The black lines within the boxes indicate the median values. ** p < 0.01 (two-tailed, two-sample t-test).