Morphohistological and biochemical features of the Guadua chacoensis (Bambusoideae; Poaceae) somatic embryogenesis

• Published in: Plant cell, tissue and organ culture tissue and organ culture, 2022-03, Vol.148 (3), p.479-499
• Main Authors: Giacomolli Polesi, Luiza, Pacheco de Freitas Fraga, Hugo, Goeten, Daniela, Panato Back, Franklin, de Medeiros Oliveira, Eliana, Steiner, Neusa, Guerra, Miguel Pedro
• Format: Article
• Language: English
• Subjects: Amino acids; Bamboo; Biochemical analysis; Biochemistry; Biomedical and Life Sciences; Callus; Carbohydrates; Embryonic growth stage; Etiolation; Explants; Friability; Life Sciences; Maltose; Mannose; Methionine; Multiplication; Original Article; Picloram; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Polyamines; Propagation; Shoots; Somatic embryogenesis; Spermidine
• ISSN: 0167-6857; 1573-5044
• DOI: 10.1007/s11240-021-02199-9

In this study, we focused on describing and characterizing the somatic embryogenesis (SE) process of Guadua chacoensis through morphohistological and biochemical analysis. For that, G. chacoensis in vitro shoots was used as explant in the induction experiments and we evaluated different Picloram concentrations (0–700 μM), explant pretreatments (constant dark/etiolation or light photoperiod), and explant position (basal, middle, and top region of the shoot). The use of 400 μM of Picloram and the basal region showed the best response for callus induction in dark- (87.5%) and light-pretreated explants (55%). During callus multiplication, we could identify the formation of embryogenic cultures (EC) and non-embryogenic cultures (NEC), which were morphologically characterized as compact and nodular, and friable and soft, respectively. As expected, only the EC were able to maturate when transferred to a Picloram-free culture medium. Biochemical characterization revealed a higher content of spermidine, arginine, methionine, maltose, and mannose in EC, highlighting their involvement with embryogenic competence in this species. In addition, we present a detailed description of the morphohistological events from callus formation until embryo maturation. Taking together, our study firstly reports a SE protocol for G. chacoensis and represents important progress for bamboo SE investigation . Our results shed light on the possibility of the SE application in bamboo species for mass propagation and in vitro conservation. Key message Induction of SE in Guadua chacoensis was strongly promoted by using etiolated explants from the basal region of shoots and Picloram, and their embryogenic competence was related to higher endogenous content of several polyamines, amino acids, and carbohydrates. Graphical abstract