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

Abstract

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 alpina (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.