Biochemical events during somatic embryogenesis in Coffea arabica L.

Abstract

Several biochemical components associated with different stages of somatic embryogenesis in coffee ( L.) are investigated using foliar explants. Soluble sugar, starch, free amino acids and total proteins were extracted and quantified at different stages of somatic embryogenesis, such as foliar segments (initial explants), primary calluses, embryogenic calluses, globular embryos, torpedoes, cotyledonary embryos and mature fruit zygotic embryos. Total soluble sugar levels increased sixfold at the initial stages of somatic embryogenesis induction. During this period, total soluble sugar in the cultures contained approximately 99.3% glucose and fructose. At 67.4 μg/mg MS, no significant changes were observed in total sugar content during the embryo's somatic maturation and regeneration. During this stage, total soluble sugar was composed of 60% sucrose. After primary callus formation, starch contents increased gradually until the culture's conclusion. Total free amino acids, particularly arginine, lysine, methionine, asparagine, glutamine and histidine, revealed a higher synthesis until the formation of the primary callus, after which they remain statistically constant up to the end of the process. During the induction of calluses, a gradual increase of total proteins occurred, which, in the differentiating and maturing of somatic embryos, did not differ statistically till the formation of a cotyledonary embryo, when rates decreased 21.8%.

Somatic embryogenesis and plant regeneration in Piper aduncum L

“…As for the differences in the content of total soluble sugars in embryogenic calli compared to non-embryogenic calli, they have also been reported in Garcinia mangstana (Maadon et al 2016) and Coffea arabica (Bartos et al 2018). More recently, Aguilar-Hernández and Loyola-Vargas (2018) emphasized the variety of proteins involved in glycolysis (conversion of carbohydrates into ATP) identified in embryogenic calli by the survey of proteomic data involved in the process of somatic embryogenesis of different species.…”

MADURACIÓN Y GERMINACIÓN DE EMBRIONES SOMÁTICOS DE Coffea arabica CV. COLOMBIA

“…Se sabe que cuando se incluyen concentraciones altas de sacarosa en los medios de cultivo, ésta entra en los tejidos de los embriones y es hidrolizada por la enzima invertasa-apoplástica, promoviendo la deposición de glucosa, fructosa y almidón en el embrión (Iraqi et al, 2005). Lo anterior hace que la presión osmótica del embrión aumente induciendo la expresión de los genes que codifican a la glutamina-sintetasa y glutamato-sintasa, involucradas en el metabolismo del nitrógeno y la deposición de proteínas de almacenamiento como globulinas, prolaminas y glutelinas, requeridas para que el embrión madure y germine (Bartos et al, 2018;Cangahuala-Inocente et al, 2009;Iraqi y Tremblay, 2001;Kubeš et al, 2014;Montalbán et al, 2010;Shewry y Halford, 2002;Stasolla et al, 2003).…”

“…Quiroz-Figueroa et al (2002) mencionaron que los embriones globulares presentan alta actividad mitótica que permite el crecimiento y desarrollo embrionario, mientras que en embriones torpedo y cotiledonares existen células con un grado de diferenciación mayor. De la misma manera, se ha observado que los niveles de proteínas, carbohidratos y de reguladores de crecimiento endógenos de los embriones en estado globular y torpedo cultivados bajo las mismas condiciones son diferentes, lo cual puede ocasionar una respuesta diferencial a las condiciones de cultivo (Bartos et al 2018). El hecho de que en la presente investigación mayor número de embriones globulares que de embriones torpedo temprano haya alcanzado la madurez indica que es mejor inducir la maduración, desde la etapa globular, reduciendo con ello tiempo, insumos y mano de obra necesarios.…”

Physical state of the culture medium triggers shift in morphogenetic pattern from shoot bud formation to somatic embryo in Solanum khasianum

“…It may be hypothesized that the shift in morphogenetic pattern towards somatic embryogenesis in liquid culture medium in S. khasianum might be because of easy accessibility of soluble nutrients and PGRs. There are several reports from different plants where liquid medium proved better for induction of somatic embryogenesis (Bartos et al 2018;Ibraheem et al 2013;Castillo et al 2000). Developing embryos passes from different intermediate stages and transition of each stage required several physiological and metabolic changes governed by the differential regulation of a set of genes.…”