Figure 1.

The overexpression of PDLP6 leads to growth defects, starch overaccumulation, and reduced long-distance phloem transportation. A) Three-week-old Arabidopsis plants were grown under a light intensity used for a standard Arabidopsis growth (110 µmol/m²/s). Images were taken using the same magnification. Scale bar = 1 cm. Four independent transgenic lines (1 to 4) were shown. HF-YFP and PDLP6-HF refer to Pro35S:HF-YFP and Pro35S:PDLP6-HF, respectively. B) Immunoblot analysis detects the expression of PDLP6-HF in 4 independent transgenic plants. An anti-Flag antibody was used to detect the expression of Flag fusion proteins. Rubisco serves as a loading control. Numbers on the side indicate molecular weights in kilodaltons (kDa). C) Starch accumulation of plants shown in A). Tissues were harvested at the end of the night and stained using Lugol's iodine solution. Images were taken using the same magnification. Scale bars = 1 cm. D) Starch staining of leaves from Col-0 and PDLP6-HF. Leaves are arranged according to their age. Scale bars = 1 cm. E) A CFDA loading assay determined long-distance phloem transport. CF signals were detected in root tips. PI was used as a root cell wall stain. Scale bars = 100 µm. F) CF fluorescent signal intensity in roots was quantified using Fiji. Each dot represents the relative signal intensity of CF from an individual root. The plot shows the mean with SEM. Col-0, n = 17; PDLP6-HF-2, n = 20; and PDLP6-HF-3, n = 22. Asterisks indicate statistically significant differences analyzed with a 2-tailed t-test (*P < 0.01).