Figure 4.

Effect of UV-B on GLP1 and GLP1-GFP protein levels as well as location. Protein gel blot, with OsGLP1-His antisera, of total protein extracts from the leaves of WT (A) grown to 4-leaf stage under 600 µmol m⁻² s⁻¹ white light in a growth chamber deficient in UV-B, and GLP1-GFPOE seedlings grown in the dark on Murashige and Skoog (MS) medium for 7 d (B) before they were exposed to 600 µmol m⁻² s⁻¹ white light supplemented with or without 50–80 µW cm⁻² UV-B for different times (hours). Confocal images of GFP fluorescence in leaf sheath of transgenic plants expressing GLP1-GFP from the Ubi promoter grown in the dark on MS medium for 7 d before they were exposed to white light and white light supplemented 50–80 µW cm⁻² UV-B for 2 h (C and E, respectively); confocal images of GFP fluorescence in leaf sheath from GLP1-GFPOE seedlings exposed to white light for 2 h, treated with 30% sucrose about 5 min (D). Bars = 25 µm. Stars denote fluorescence in the cell, short arrows and long arrows denote fluorescence in the plasma membrane and apoplast, respectively.