Effects of IAA on the Elongation and Cell Wall Glycosidase Activities in Excised Rape (Brassica napus L. cv. Yongdang) Hypocotyl Segments

유채 하배축 분절의 신장과 세포벽 분해효소의 활성에 미치는 IAA의 효과

Effects of IAA on the elongation and cell wall hlysocidase activities were investigated in excised rape (Brassica napus L. cv. Yongdang) hypocotyl segments. IAA promoted the elongation of rape hypocotyl segments. In rape hypocotyls, the first 10-mm segments from the hook exhibited maximal elongation and the capacity of elongation was gradually decreased with increasing distance of each 10-mm from the hook. A good correlation has been obtained between the magnitude of endogenous growth and the activities of $\alpha$, $\beta$-glucosidase and $\alpha$, $\beta$-galactosidase. However, exogenous application of IAA did not seem to enhance the tissue with IAA resulted in acidification of the incubation medium. From these data, we can conclude that IAA seems to enhance elongation of the tissue segments, at least in part, by releasing hydrogen ion into cell wall, some of which may participate in the cell wall extension process, but does not seem to trigger the activation of $\alpha$, $\beta$-glucosidase and $\alpha$, $\beta$-galactosidase.