Synthesis and accumulation of free amino acids during somatic and zygotic embryogenesis of Acca sellowiana (O. Berg.) Burret

Abstract

Somatic embryogenesis (SE) is an analogous process to zygotic embryogenesis (ZE); both complex processes are influenced by a significant number of genetic and environmental factors. Amino acids are considered important regulators of morphogenesis in several plant species, therefore the aim of this study was to determine the role of amino acids in embryo ontogeny in Acca sellowiana. Endogenous levels of amino acids were quantified at different stages of development during both direct and indirect somatic embryogenesis (DSE and ISE) and during ZE. During ZE, there was an increase in total amino acids between 18 and 27 days after pollination. During ISE and DSE, the highest contents were detected from 3 to 15 days after inoculation, coinciding with the induction of somatic embryos. In ZE, glutamine and asparagine appeared to be fundamental to the process of induction of zygotic embryos. On the other hand, the induction of somatic embryos that appeared require glutamine, gamma-aminobutyric acid (GABA) and glutamic acid. The results suggest the involvement of amino acids in the ontogenesis of zygotic and somatic embryogenesis directly and indirectly in A. sellowiana, indicating requirements for specific amino acids for each event of development.

Keywords: Acca sellowiana, somatic embryogenesis, zygotic embryogenesis, glutamine, asparagine, amino acids

African Journal of Biotechnology Vol. 12(22), pp. 3455-3465