Figure 4.

Epidermal phyB Non-Cell-Autonomously Inhibits Hypocotyl Negative Gravitropism in Response to Red Light.

(A) Inhibition of hypocotyl negative gravitropism by ML1pro-driven epidermal phyB. Seedlings from each line after growing on vertical plates for 4 d in continuous red light (Rc).

(B) Hypocotyl negative gravitropism was quantified by counting seedlings growing within 45° of vertical. Error bars indicate sd (n = 3, 80 seedlings each).

(C) Epidermal phyB induces degradation endodermal amyloplast starch granules. Four-day-old red-light-grown seedlings were stained with Lugol’s iodine to reveal the amyloplast starch granules (brown spots). Small inset images show amyloplast starch granules in the columellar cells of root tips.