Figure 6.

Endomembrane aggregation and intracellular accumulation of cell wall polysaccharides in mur3-3 plants. A, Endomembrane aggregation in mur3-3 plants is suppressed by knocking out XXT2 or XXT5. Col-0 (wild-type [WT]) and mutant plants were individually transformed with the SP-2SC-GFP (for signal peptide of pumpkin 2S albumin followed by a linker of GGG and the C-terminal 18-amino acid sequence of pumpkin 2S albumin) construct and grown with a 14-h-light (19°C) and 10-h-dark (15°C) cycle or a 14-h-light (28°C) and 10-h-dark (24°C) cycle. Images of epidermal cells of 14-d-old cotyledons expressing the endomembrane-targeted SP-2SC-GFP were obtained using an inverted laser scanning confocal microscope. Bar = 10 µm. B, Immunocytochemistry reveals intracellular aggregates (see arrows) containing XyG and pectin in mur3 hypocotyls. Top, Toluidine blue-stained cross sections. CCRC-M88 recognizes XyG, CCRC-M1 recognizes fucosylated XyG, and CCRC-M38 recognizes deesterified homogalacturonan. Bar = 50 µm.