Physiological, Metabolic, and Transcriptomic Analyses Reveal Mechanisms of Proliferation and Somatic Embryogenesis of Litchi ( Litchi chinensis Sonn.) Embryogenic Callus Promoted by D-Arginine Treatment

• Published in: International journal of molecular sciences 2024-04, Vol.25 (7), p.3965
• Main Authors: Cao, Ludan, Wang, Guo, Ye, Xiuxu, Li, Fang, Wang, Shujun, Li, Huanling, Wang, Peng, Wang, Jiabao
• Format: Article
• Language: English
• Subjects: Analysis; Arginine; Cell differentiation; Cell Division; Cyclopentanes; Cytokinins; D-Arg; embryogenic callus; Embryonic Development; Embryos; Enzymes; Gene expression; Genes; Glucosides; Glycine; Hormones; Hydrogen Peroxide; Isoleucine - analogs & derivatives; litchi; Litchi - genetics; Metabolism; Metabolites; Oxidation; Oxylipins; Physiological aspects; Physiology; plant endogenous hormones; polyamine metabolism; Polyamines; Putrescine; Spermidine; Spermine; transcriptome analysis
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms25073965

D-arginine (D-Arg) can promote embryogenic callus (EC) proliferation and increase the rate of somatic embryo induction of litchi ( Sonn.), yet the mechanism underlying the processes is incompletely understood. To investigate the mechanism, physiological responses of polyamines (PAs) [putrescine (Put), spermidine (Spd), and spermine (Spm)] were investigated for D-Arg-treated litchi EC and enzyme activity related to polyamine metabolism, plant endogenous hormones, and polyamine- and embryogenic-related genes were explored. Results showed that the exogenous addition of D-Arg reduces the activity of diamine oxidase (DAO) and polyamine oxidase (PAO) in EC, reduces the production of H O , promotes EC proliferation, and increases the (Spd + Spm)/Put ratio to promote somatic embryo induction. Exogenous D-Arg application promoted somatic embryogenesis (SE) by increasing indole-3-acetyl glycine (IAA-Gly), kinetin-9-glucoside (K9G), and dihydrozeatin-7-glucoside (DHZ7G) levels and decreasing trans-zeatin riboside (tZR), N-[(-)-jasmonoyl]-(L)-valine (JA-Val), jasmonic acid (JA), and jasmonoyl-L-isoleucine (Ja-ILE) levels on 18 d, as well as promoting cell division and differentiation. The application of exogenous D-Arg regulated EC proliferation and somatic embryo induction by altering gene expression levels of the WRKY family, AP2/ERF family, C3H family, and C2H2 family. These results indicate that exogenous D-Arg could regulate the proliferation of EC and the SE induction of litchi by changing the biosynthesis of PAs through the alteration of gene expression pattern and endogenous hormone metabolism.