Relationships of Selected Endogenous Factors Associated with Direct Somatic Embryogenesis of Coffee (Coffea arabica L.)

D K Isutsa,C M Mweu,A B Nyende,R N Mayoli

doi:10.24297/jaa.v8i1.7378

Abstract

Coffee is one of the most important cash crops produced in the world with great economic returns to growers and national gross domestic product. Somatic embryogenesis is a morphogenetic processes leading to plantlet regeneration and these processes are coupled with changes in the levels of primary metabolites. The present experiment established relationships of endogenous substances with direct somatic embryogenesis of coffee ‘Ruiru 11’. Laboratory experiments were set up at Coffee Research Institute, Ruiru-Kenya between 2014 and 2017. The set up was in a completely randomised design, replicated three times and repeated once. Third leaf pair explants were excised from 8-month-old greenhouse-grown mother plants and cultured in half strength Murashige and Skoog basal salts augmented with Thidiazuron. Once embryos had developed, the cultures were analysed for endogenous substances using HPLC and GCMS. Sucrose, phenolics, alkaloids, amino acids, fatty acids and their derivatives correlated positively, whereas fructose and glucose correlated negatively with the other biochemical components. Endogenous sucrose, chlorogenic acid, caffeine amino acid, fatty acids and their derivatives are potential biomarkers for coffee somatic embryogenesis, whereas endogenous fructose and glucose are inhibitors of the same. Further studies regarding the status of the biochemical components, especially in particular stages of embryo development should be conducted to establish treatments that can improve coffee direct somatic embryo development.

Highlights

Embryogenesis is a spatio-temporally organized developmental process that is central to the life cycles of diverse plant species (Navarro et al, 2017)
This paper presents relationships of glucose, fructose, sucrose, chlorogenic acid, caffeine, phyto-components and amino acids with direct somatic embryogenesis of coffee
To narrow down which of the endogenous biochemical components present during somatic embryogenesis of Ruiru 11 could be utilized as biochemical markers for somatic embryogenesis, they were analysed to identify a core set that were consistently detected in embryogenic and non-embryogenic cultures

Summary

Introduction

Embryogenesis is a spatio-temporally organized developmental process that is central to the life cycles of diverse plant species (Navarro et al, 2017). Growth of embryogenic cultures is usually associated with changes in synthesis and mobilization of proteins, carbohydrates and lipids. The levels of these substances vary at different stages of cell culture (Lulsdorf et al, 1992), where they act in signal transduction pathway or supply substrates and energy required for cell growth and morphogenesis (Nomura and Komamine, 1995). Somatic embryogenesis could be a response to stress (Dudits et al, 1995) and is associated with adaptation mechanisms, such as cell reprogramming and modification in physiological and metabolic pathways (Pasternak et al, 2002). This paper presents relationships of glucose, fructose, sucrose, chlorogenic acid, caffeine, phyto-components and amino acids with direct somatic embryogenesis of coffee

Methods

Discussion

Conclusion