Proteomic Analysis of S-Nitrosation Sites During Somatic Embryogenesis in Brazilian Pine, Araucaria angustifolia (Bertol.) Kuntze

Abstract

Cysteine S-nitrosation is a redox-based post-translational modification that mediates nitric oxide (NO) regulation of various aspects of plant growth, development and stress responses. Despite its importance, studies exploring protein signaling pathways that are regulated by S-nitrosation during somatic embryogenesis have not been performed. In the present study, endogenous cysteine S-nitrosation site and S-nitrosated proteins were identified by iodo-TMT labeling during somatic embryogenesis in Brazilian pine, an endangered native conifer of South America. In addition, endogenous –S-nitrosothiol (SNO) levels and S-nitrosoglutathione reductase (GSNOR) activity were determined in cell lines with contrasting embryogenic potential. Overall, we identified an array of proteins associated with a large variety of biological processes and molecular functions with some of them already described as important for somatic embryogenesis (Class IV chitinase, pyruvate dehydrogenase E1 and dehydroascorbate reductase). In total, our S-nitrosoproteome analyses identified 18 endogenously S-nitrosated proteins and 50 in vitro S-nitrosated proteins (after GSNO treatment) during cell culture proliferation and embryo development. Furthermore, SNO levels and GSNOR activity were increased during embryo formation. These findings expand our understanding of the Brazilian pine proteome and shed novel insights into the potential use of pharmacological manipulation of NO levels by using NO inhibitors and donors during somatic embryogenesis.

The Crucial Role of SlGSNOR in Regulating Postharvest Tomato Fruit Ripening

“…As NO is unstable in the plant, it usually exists in the form of S -nitrosoglutathione (GSNO) [ 11 ]. Alternatively, the GSNO level is always in equilibrium with the protein S -nitrosothiols (SNOs), which may affect protein S -nitrosylation reactions [ 12 ]. In addition, GSNO can be irreversibly degraded by S -nitrosoglutathione reductase (GSNOR) [ 13 , 14 ].…”

Glutathione Plays a Positive Role in the Proliferation of Pinus koraiensis Embryogenic Cells

“…Especially for long reproductive cycle pine species, somatic embryogenesis could contribute to rapid production of a large number of regenerated plants with stable characteristics, which has great applicative value [ 5 ]. Somatic embryogenesis is an effective model system to study morphological, physiological, molecular, and biochemical aspects of embryonic development of trees [ 6 , 7 , 8 ]. In the past decades, research on conifer somatic embryogenesis was mainly focused on the regulation technology and mechanism in the embryogenic callus (EC) induction stage and somatic embryo maturation stage [ 9 , 10 , 11 ].…”