Carbohydrate-mediated responses during zygotic and early somatic embryogenesis in the endangered conifer, Araucaria angustifolia

Abstract

Three zygotic developmental stages and two somatic Araucaria angustifolia cell lines with contrasting embryogenic potential were analyzed to identify the carbohydrate-mediated responses associated with embryo formation. Using a comparison between zygotic and somatic embryogenesis systems, the non-structural carbohydrate content, cell wall sugar composition and expression of genes involved in sugar sensing were analyzed, and a network analysis was used to identify coordinated features during embryogenesis. We observed that carbohydrate-mediated responses occur mainly during the early stages of zygotic embryo formation, and that during seed development there are coordinated changes that affect the development of the different structures (embryo and megagametophyte). Furthermore, sucrose and starch accumulation were associated with the responsiveness of the cell lines. This study sheds light on how carbohydrate metabolism is influenced during zygotic and somatic embryogenesis in the endangered conifer species, A. angustifolia.

Marcadores bioquímicos associados ao metabolismo de carboidratos durante a embriogênese zigótica e somática de >i<Araucaria angustifolia >/i<(Bertol.) Kuntze

“…Due to the molecular, biochemical, physiological and morphological similarities between zygotic and somatic embryogenesis, the latter has been used as a model of experimental system for plant development in the physiological, biochemical and molecular aspects (Navarro et al 2017, Elbl et al 2015a, Pullman and Bucalo 2014, Schlögl et al 2012a, 2012b, Steiner et al GENERAL INTRODUCTION 2012, Vieira et al 2012, Durzan et al 2012, Lara-Chavez et al 2012, Balbuena et al 2009, Steiner et al 2007, von Arnold et al 2002. Integrative approaches to zygotic and somatic embryogenesis are fundamental for understanding these processes, establishing efficient protocols, and mimicking the conditions necessary for correct embryogenic development (Navarro et al 2017, Elbl et al 2015a, Garcia-Mendiguren et al 2015.…”

“…In the past twenty five years, the Laboratory of Plant Cell Biology In this perspective, the research group has been using innovative methodologies that allow a deeper understanding of molecular aspects, including the study of high throughtput (RNAseq) and quantitative proteomics (GeLC-MS / MS) (dos Santos et al 2016, Elbl et al 2015a, 2015b, as well as on biochemical and physiological aspects (de Oliveira et al 2018, Navarro et al 2017, de Oliveira et al 2017, Jo et al 2014. Through the transcriptome, 112,772 unigenes were obtained from the de novo database assembly (Elbl et al 2015a).…”

“…The results described in chapter 1 and published at PloS one (Navarro et al 2017), elucidated through biochemical and molecular parameters, the regulation of carbohydrates metabolism variation during zygotic and somatic embryogenesis. In this study, it was verified that: a) the TOR/SnRK1 system apparently operates in the modulation of the embryogenic responses; b) the sugar sensing and signaling-mediated responses during somatic embryo development resemble to zygotic embryogenesis, which occur mainly during the early stages; c) the accumulation of sucrose and starch during somatic embryo development were important and this pattern can be associated with the responsiveness for A. angustifolia.…”

“…As the embryos advance their development (complete formation of cotyledons), concentrations of AIA and gibberellic acid (GA) tend to decrease and ABA concentration increases, characterizing in this stage the maturation phase of the seed, Astarita et al 2003a, Astarita et al 2003b). The polyamines (PAs) profile is also altered with a high concentrations of putrescine (Put) and spermidine (Spd) in the early stages of development(de Oliveira et al 2017, Astarita et al 2003b, with an increase in spermine (Spm) of the cotyledons and development of the mature seeds(de Oliveira et al 2017, Astarita et al 2003b). The existence of stage-specific proteins, that could be used as biochemical markers, were identified.…”

“…2014. Many efforts are being made to identify biochemical and molecular markers for an early selection of suitable and competent genotypes for the formation and evolution of viable somatic embryos(Navarro et al 2017, dos Santos et al 2016, Elbl et al 2015a, Jo et al 2014). However, the main reason for limited production of A. angustifolia somatic embryos is the insufficient knowledge of the underlying regulatory process, especially in maturation phase during embryogenesis process (dosSantos et al 2016, Elbl et al 2015, Jo et al 2014).…”