Effects of Gibberellin and Abscisic Acid on Asexual Reproduction from Graptopetalum paraguayense Leaves

Abstract

Graptopetalum paraguayense E. Walther is an edible succulent plant that is native to Mexico. When leaves of G. paraguayense are detached from the mother plant, shoots and roots regenerate from the leaf base. To investigate the endogenous hormonal regulation of plant regeneration in G. paraguayense, we evaluated the effects of applying gibberellin (GA), abscisic acid (ABA), and phytohormone biosynthesis inhibitors to leaves detached from the mother plant. GA3 and paclobutrazol did not affect plant regeneration of G. paraguayense, whereas ABA treatment significantly suppressed plant regeneration. When leaves were treated with the ABA biosynthesis inhibitor fluridone at 10 μM, the frequency of shoot regeneration was more than twice that of the control on the 6th day after leaf detachment. In addition, when both fluridone and ABA were applied at the same time, the frequency of plant regeneration decreased to control levels or below. Endogenous ABA in leaves was approximately 1.3 ng gFW−1 just after leaf detachment, decreased to 0.3 ng gFW−1 by the 1st day after leaf detachment, and increased to 3.0 ng gFW−1 by the 9th day after leaf detachment. These findings indicate that ABA plays an important role in suppression of plant regeneration in G. paraguayense. Although plant regeneration during storage and transportation currently reduces the economic value of G. paraguayense, our findings may provide a method to delay unwanted plant formation at the leaf base.