Effect of TIBA, fluridone and salicylic acid on somatic embryogenesis and endogenous hormone and sugar contents in the tree fern Cyathea delgadii Sternb.

Abstract

Somatic embryogenesis (SE) in the tree fern Cyathea delgadii was first described in 2015 and since then has been used to exploration of this phenomenon in cryptogamic plants. To deepen the knowledge about the hormonal control of SE, stipe explants were cultured on media supplemented with hormone biosynthesis and transport inhibitors (HBTIs). In the presence of 30 µM 2,3,5-triiodobenzoic acid (TIBA), or 40 µM fluridone or 125 µM salicylic acid (SA), somatic embryo production was totally inhibited. The quantitative analysis of the changes in endogenous hormone and sugar contents was conducted every 2 days within 10-day-long initial culture. The results showed that the concentrations of endogenous indole-3-acetic acid (IAA), abscisic acid (ABA), cytokinins (CKs) and soluble sugars were strongly modified either by TIBA and fluridone. Under their influence, the contents of cytokinins such as c-Z, c-ZR, t-Z, t-ZR, KinR were reduced to barely detectable levels. Treatment with SA results in the changes in endogenous IAA and sugar contents. It also modifies the IAA/CKs ratio; however, excluding the first 2 days of culture, the concentrations of ABA and cytokinins were kept on the control level. All HBTIs significantly increased the kinetin (Kin) content. Our work sheds new light on the relationships between the biosynthetic inhibitors and phytohormones and sugars in the process of early SE. It can be helpful to study the role of hormones in acquisition of embryogenic competence.

Explant type and stress treatment determine the uni- and multicellular origin of somatic embryos in the tree fern Cyathea delgadii Sternb.

“…The basis for the induction of SE in C. delgadii is an appropriate hormonal balance in explant cells established by etiolation of donor plantlets (Grzyb et al 2017). We also improved the current understanding of physiological and molecular processes involved in the induction and expression of early SE in this species (Grzyb et al 2018;Domżalska et al 2017). Our previous achievements have been summarised in the latest review article (Mikuła et al 2018).…”

“…Although SE has been successfully achieved in numerous species of seed plants, only a few published reports describe this phenomenon in monilophytes, and all these studies were performed on the tree fern Cyathea delgadii Sternb. (Mikuła et al 2015a, b;Domżalska et al 2017;Grzyb et al 2017Grzyb et al , 2018. These investigations demonstrated that somatic embryos of C. delgadii are formed directly from single epidermal cells.…”

“…These investigations demonstrated that somatic embryos of C. delgadii are formed directly from single epidermal cells. Embryogenic cultures of ferns, that represent the closest living relatives of spermatophytes (Pryer et al 2001), promise to be useful in the study of some fundamental problems relating to somatic embryo initiation and development (Domżalska et al 2017;Grzyb et al 2017Grzyb et al , 2018. However, a better understanding of factors that control the somatic embryo origin and improve the efficiency of SE in ferns is still required.…”

Signaling Overview of Plant Somatic Embryogenesis

“…Understanding the physiological and molecular mechanisms by which the induction (direct or indirect) of SE occurs is a crucial step for its manipulation (Grzyb et al, 2018). Several factors can induce SE.…”

Protective mechanisms of melatonin against selenium toxicity in Brassica napus: insights into physiological traits, thiol biosynthesis and antioxidant machinery

“…Under stress conditions, MT promotes plant growth, delays senescence, and modulates photoperiod responses and root architecture [18]. MT may also protect plants against abiotic stressors such as heat [19], cold [20], salt [21], drought [22] and heavy metals [23]. MT augments plant stress tolerance by inducing the enzymatic detoxification of free radicals and reactive oxygen species (ROS) [24] and by scavenging excess ROS [23–25].…”