RELATIONSHIPS BETWEEN CELL-WALL BETA-1,3-ENDOGLUCANASE ACTIVITY AND AUXIN-INDUCED ELONGATION IN MUNG BEAN HYPOCOTYL SEGMENTS

A beta-1,3-endoglucanase (mol. wt. 43,000 and pI around 7) was immunol ocalized in outer epidermal cell walls and pericycle walls in the elon gation zone of mung bean hypocotyls. Hypocotyl segments infiltrated wi th anti-beta-1,3-endoglucanase antibodies show a clear reduction in th eir auxin-induced elongation when the auxin treatment was maintained f or a long period (15 h). These results suggest that, even in dicotyled ons, rupture of some beta-1,3-glycosyl linkages might be associated wi th the cell-wall loosening, which is responsible for auxin-induced elo ngation, or that some beta-1,3-glucanases are indirectly involved in a uxin-induced elongation through their auxin-binding properties.