Fig. 1. Dot-blot screening for XET activity in total extracts from diverse plant organs. (a) XET assays in 96-well format, on paper impregnated with 0.3% xyloglucan + 5 μM XGO–SR; (b) control assays on paper impregnated with XGO–SR alone. Rows A–D and E–H show results with low- and high-salt extracts, respectively, from the plant organs listed on the right. The enzyme solutions (4 μl) were incubated on the papers for 13 h at 22 °C. (c) XET assays on paper impregnated with 0.3% xyloglucan + 5 μM XGO–SR. The enzyme extracts (low-salt buffer) were from parsley (P) or asparagus (A), and either undiluted (row '1') or 2–8-fold diluted (rows '/2' to '/8'); 4 μl was applied to the paper and incubated at 22 °C for 0.5, 1, 2, 4, 6 or 12 h, as indicated.