Endogenous quantification of abscisic acid and indole-3- acetic acid in somatic and zigotic embryos of Nothofagus alpina (Poepp. &| Endl.) Oerst.

Pricila Cartes Riquelme1*, Darcy Ríos Leal1, Kátia Sáez Carrillo2, Matilde Uribe Moraga1, Sofía Valenzuela Aguilar1, Stephen Joseph Bolus3, and Manuel Sánchez Olate1

Abscisic acid (ABA) and indole-3-acetic acid (IAA) participate in the propagation of plants by somatic embryogenesis, causing polar structural differentiation of the embryo. The goal of the assay was to compare endogenous levels of ABA and IAA between somatic embryos (SE) and zygotic embryos (ZE) of Nothofagus alpine (Poepp. & Endl.) Oerst. In this study, a somatic embryo maturation assay involving the addition of varying concentrations of exogenous ABA was performed on cotyledonary-stage of N. alpina. Furthermore, the endogenous levels of ABA and IAA were quantified in the immature ZE, the mature ZE, and the embryonic axis of a mature embryo of N. alpina. The current study utilized high performance liquid chromatography (HPLC) for quantification. The maturation treatments performed did not present significant differences in the endogenous ABA levels in SE. However, significant differences did exist in levels of ABA and IAA between SE submitted to the different maturation treatments and mature ZE of N. alpina. The application of exogenous ABA to the culture medium increased endogenous ABA levels, therefore, increasing the number of germinated somatic embryos. Thus, the plant conversion process was also successfully completed in somatic embryos of N. alpina.

Keywords: Somatic embryogenesis, maturation, germination, HPLC.
1Universidad de Concepción, Facultad Ciencias Forestales, Casilla 160-C, Concepción, Chile. *Corresponding author (pcartes.r@gmail.com).
2Universidad de Concepción, Facultad de Ciencias Físicas y Matemáticas, Av. Esteban Iturra s/n, Barrio Universitario, Concepción, Chile.
3Clemson University, Department of Biochemistry, 100 Jordan Hall Clemson, South Carolina 29634, USA.