CO2 enrichment and supporting material impact the primary metabolism and 20-hydroxyecdysone levels in Brazilian ginseng grown under photoautotrophy

• Published in: Plant cell, tissue and organ culture tissue and organ culture, 2019-10, Vol.139 (1), p.77-89
• Main Authors: Ferreira, Perácio Rafael Bueno, da Cruz, Ana Claudia Ferreira, Batista, Diego Silva, Nery, Lays Araújo, Andrade, Itainá Gonçalves, Rocha, Diego Ismael, Felipe, Sérgio Heitor Sousa, Koehler, Andréa Dias, Nunes-Nesi, Adriano, Otoni, Wagner Campos
• Format: Article
• Language: English
• Subjects: Amines; Amino acids; Aromatic compounds; Biomedical and Life Sciences; Carbon dioxide; Enrichment; Gas exchange; Ginseng; Hydroxyproline; Inositol; Intermediates; Life Sciences; Metabolic response; Metabolism; Metabolites; Original Article; Photoautotrophy; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant propagation; Plant Sciences; Plants (botany); Polyamines; Porosity; Propagation; Sugar; Tricarboxylic acid cycle; Ventilation
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-019-01664-w

In vitro photoautotrophic propagation system has been successfully established for Pfaffia glomerata, a medicinal species that produces the phytoecdysteroid 20-hydroxyecdysone (20E) under forced ventilation and CO 2 enrichment. For that, an adequate supporting material with high porosity in place of agar is required. In this study, we investigated metabolic and morpho-anatomical alterations of two accessions (Ac) of P. glomerata (Ac 22 and Ac 43) under photoautotrophy conditions, using two supporting materials (agar and Florialite ® ) and two CO 2 concentrations (360 and 1000 µL CO 2 L −1 ). High CO 2 concentration and the use of Florialite ® as supporting material enhanced the production of 20E, and influenced on the levels of amino acids, sugars, tricarboxylic acid cycle intermediates, stress related metabolites (aromatic amines and shikimate), and osmotic adjustment-related compounds (hydroxyproline, aspartate and myo-inositol). Interestingly, Ac 22 displayed less tolerance to stress caused by low photoautotrophy compared to Ac 43, as indicated by the higher total polyamines in Ac 22. Moreover, the accessions showed different metabolic responses under photoautotrophy. These findings provide a better understanding of how the supporting material and CO 2 enrichment influence in vitro metabolism under photoautotrophic system in P. glomerata , wherein higher levels of gas exchange, enabled by use of Florialite ® and CO 2 enrichment, increased total sugars as well as the levels of 20E in the plants. This information will be fundamental to optimize the in vitro culture systems of P. glomerata for the production of 20E. Key message Photoautotrophic propagation has the unique advantage of combining biological and environmental perspectives, resulting in morpho-physiologically well-adjusted plants grown in vitro or ex vitro. Our results revealed that the combined use of CO 2 enrichment (1000 μL CO 2 L −1 ) and supporting material (Florialite ® ) had great influence in the in vitro performance of P. glomerata and increased 20-hydroxyecdysone content. This combination also led to increased levels of amino acids, sugars, TCA cycle intermediates, and stress-related metabolites such as aromatic amines and shikimate, and osmotic adjustment-related compounds (hydroxyproline, aspartate, and myo-inositol).