Phenylpropanoids Are Connected to Cell Wall Fortification and Stress Tolerance in Avocado Somatic Embryogenesis

Abstract

Somatic embryogenesis (SE) is a valuable model for understanding the mechanism of plant embryogenesis and a tool for the mass production of plants. However, establishing SE in avocado has been complicated due to the very low efficiency of embryo induction and plant regeneration. To understand the molecular foundation of the SE induction and development in avocado, we compared embryogenic (EC) and non-embryogenic (NEC) cultures of two avocado varieties using proteomic and metabolomic approaches. Although Criollo and Hass EC exhibited similarities in the proteome and metabolome profile, in general, we observed a more active phenylpropanoid pathway in EC than NEC. This pathway is associated with the tolerance of stress responses, probably through the reinforcement of the cell wall and flavonoid production. We could corroborate that particular polyphenolics compounds, including p-coumaric acid and t-ferulic acid, stimulated the production of somatic embryos in avocado. Exogen phenolic compounds were associated with the modification of the content of endogenous polyphenolic and the induction of the production of the putative auxin-a, adenosine, cellulose and 1,26-hexacosanediol-diferulate. We suggest that in EC of avocado, there is an enhanced phenylpropanoid metabolism for the production of the building blocks of lignin and flavonoid compounds having a role in cell wall reinforcement for tolerating stress response. Data are available at ProteomeXchange with the identifier PXD019705.

Transcriptomes analysis reveals novel insight into the molecular mechanisms of somatic embryogenesis in Hevea brasiliensis

“…The most representative pathways were phytohormones signaling pathway, biosynthesis of phenylpropanoid, and sucrose and starch metabolism in CE vs. AE and MCE vs. WAE. The significant role of phenylpropanoid biosynthesis in plant SE development has been studied, this pathway is associated with the tolerance of stress responses, probably through the reinforcement of the cell wall [ 57 ]. The phenylpropanoid biosynthesis-related genes were significantly enriched in papaya embryogenic callus [ 25 ] and in strawberry embryogenic callus [ 19 ].…”

Transcriptomes analysis reveals novel insight into the molecular mechanisms of somatic embryogenesis in Hevea brasiliensis

“…The most representative pathways were phytohormones signaling pathway, biosynthesis of phenylpropanoid, and sucrose and starch metabolism in CE vs. AE and MCE vs. WAE. The signi cant role of phenylpropanoid biosynthesis in plant SE development has been studied, this pathway is associated with the tolerance of stress responses, probably through the reinforcement of the cell wall [57]. The phenylpropanoid biosynthesis-related genes were signi cantly enriched in papaya embryogenic callus [25] and in strawberry embryogenic callus [19].…”

Current Proteomic and Metabolomic Knowledge of Zygotic and Somatic Embryogenesis in Plants

“…The authors suggested that this pathway was linked to stress tolerance responses, probably through the reinforcement of the cell wall and production of flavonoids. Furthermore, p-coumaric acid and t-ferulic acid favored the formation of globular structures in EC [33]. An untargeted metabolomic study during SE in the medicinal plant Silybum marianum showed the overaccumulation of cinnamic acid, kaempferol, quercetin, myricetin, linolenic acid, and 5-enolpyruvylshikimate-3-phosphate in globular somatic embryos [34].…”

“…Altogether, proteomics studies highlight the essential role of ROS homeostasis and modulation of growth regulators during the acquisition of embryogenic potential. (4), vitamin E biosynthesis (5), microtubule-based process (6), protein refolding (7), biosynthetic process (8), unidimensional cell growth (9), seed coat development (10), photorespiration (11), pyrimidine nucleobase metabolism (13), photosynthesis ( 14), 'de novo' GDP-L-fucose biosynthetic process (15), 'de novo' pyrimidine nucleobase biosynthetic process (16), wax biosynthesis (17), cell wall pectin metabolism (18), response to other organism (19), amylopectin biosynthesis (20), starch biosynthesis (21), DNA replication (22), transcription by RNA polymerase I (23), chromosome segregation (24), carbohydrate metabolism (25), protein folding (26), ATP metabolic process (27), selenium compound metabolism (28), glycerol-3-phosphate metabolism (29), one-carbon metabolism (30), cellular amino acid biosynthesis (31), cell plate assembly (32), actin filament bundle assembly (33), positive regulation of RNA polymerase II transcription preinitiation complex assembly (34), protein targeting to chloroplast (35), calcium ion transmembrane transport (36), glycosyl compound metabolism (37), cortical microtubule organization (38), intra-Golgi vesicle-mediated transport (39), cell redox a homeostasis (40), amino sugar metabolism (41), dTDP-rhamnose biosynthesis (42), glycoside Catabolism (43), L-ascorbate biosynthesis ( 44), (R)-2-hydroxy-alpha-linolenate biosynthesis (45), mRNA splicing, via spliceosome (46), heterochromatin organization (47), heterochromatin organization (48). …”