Transcriptomic and physiological analysis identifies a gene network module highly associated with brassinosteroid regulation in hybrid sweetgum tissues differing in the capability of somatic embryogenesis

Abstract

Somatic embryogenesis is a preferred method for large-scale production of forest trees due to its high propagation efficiency. In this study, hybrid sweetgum leaves with phase changes from mature to embryogenic state were selected as experimental material to study somatic embryo initiation. Embryogenicity ranged from high to low, i.e. from 45%, 25%, and 12.5% to 0, with the samples of embryogenic callus (EC), whiten leaf edge (WLI), whiten leaf (WLII), and green leaf (GL) respectively. High correlations existed between embryogenicity and endogenous brassinosteroids (BRs) (r = 0.95, p < 0.05). Similarly, concentrations of endogenous BRs of the sample set correlated positively (r = 0.93, 0.99, 0.87, 0.99, 0.96 respectively, P < 0.05) to expression of somatic embryo (SE)-related genes, i.e. BBM, LEC2, ABI3, PLT2, and WOX2. Hierarchical cluster and weighted gene coexpression network analysis identified modules of coexpressed genes and network in 4820 differentially expressed genes (DEGs) from All-BR-Regulated Genes (ABRG). Moreover, exogenously-supplemented epiBR, together with 2,4-D and 6-BA, increased embryogenicity of GL-sourced callus, and expression of SE- and auxin-related genes, while brassinazole (BRZ), a BR biosynthesis inhibitor, reduced embryogenicity. Evidences obtained in this study revealed that BRs involved in phase change of leaf explants and may function in regulating gene expression and enhancing auxin effects. This study successfully established protocols for inducing somatic embryogenesis from leaf explants in hybrid sweetgum, which could facilitate the propagation process greatly, and provide theoretical basis for manipulating SE competence of explants in ornamental woody plants.

Establishment of in vitro regeneration system and molecular analysis of early development of somatic callus in Capsicum chinense and Capsicum baccatum

“…Plant biotechnology, including tissue culture and genetic engineering, is gradually becoming an important breeding method to promote the improvement of pepper breeding. It is well known that several genes are involved in explant regeneration, including WOX , BBM , LEC , and WUS ( Zhao et al., 2022 ). Our results indicated that phytohormones play an important role in callus formation by regulating the expression of regeneration-related genes.…”

“…Roles of WOX gene in the regeneration of pepper WOX family genes are important in a variety of processes, ranging from callus formation to organ development (Kim et al, 2018;Wang C. et al, 2021;Willoughby and Nimchuk, 2021). It was reported that WOX2 and WOX8/9 were involved in differentiation and somatic embryogenesis (Palovaara et al, 2010;Zhao et al, 2022). Based on the activity of WIND1, WOX13 was rapidly induced, which is a key regulator of callus formation (Ikeuchi et al, 2021).…”

Comprehensive Genetic Analysis of Tuberculosis and Identification of Candidate Biomarkers

“…With the development of bioinformatics technology, more and more new techniques are applied to analyze expression profile data. Differential gene analysis is the most classical analysis method, which plays an important role in this field of biomarkers by a series of statistical algorithms to find differential genes between different subgroups ( Liu et al, 2022 ; Zhao et al, 2022 ). WGCNA (weighted gene co-expression network analysis) is a topological network that can establish the linkage between gene modules and clinical traits, and the genes classified into the same module are all linked to selected clinical traits, which can then be used for subsequent analysis and experiments ( Nguyen et al, 2021 ; Ye et al, 2021 ).…”

Proper doses of brassinolide enhance somatic embryogenesis in different competent Korean pine cell lines during embryogenic callus differentiation

“…Brassinolide (BL) is the first discovered form of brassinosteroids (BRs) with the most bioactive properties and BRs play a crucial role in various aspects of plant growth and development, including cell growth and division, vascular bundle differentiation, cell redifferentiation, and growth under stress conditions ( Kim et al., 2009 ; Wei and Li, 2016 ; Bajguz et al., 2020 ; Kour et al., 2021 ; Singh et al., 2021 ; Manghwar et al., 2022 ). The regeneration and multiplication rate of in vitro cultured material could be improved by the addition of BRs to the medium for callus induction, somatic embryogenesis and embryogenic callus formation ( Singh et al., 2021 ); 4 types of hybrid sweetgum ( Liquidambar styraciflua × L. formosana ) with different embryogenic ties should be highly correlated with endogenous BRs; and BR concentrations of the samples should be positively correlated with the expression of genes associated with somatic embryos ( Zhao et al., 2022 ). In general, the general aspects of BRs have been studied in relative detail ( Singh et al., 2021 ; Chen et al., 2022 ), but Somatic embryogenesis (SE) involves the use of BRs, including their application effects and physiological and genetic mechanisms ( Kim and Moon, 2014 ; Chone et al., 2018 ; Zhao et al., 2022 ).…”

“…The regeneration and multiplication rate of in vitro cultured material could be improved by the addition of BRs to the medium for callus induction, somatic embryogenesis and embryogenic callus formation ( Singh et al., 2021 ); 4 types of hybrid sweetgum ( Liquidambar styraciflua × L. formosana ) with different embryogenic ties should be highly correlated with endogenous BRs; and BR concentrations of the samples should be positively correlated with the expression of genes associated with somatic embryos ( Zhao et al., 2022 ). In general, the general aspects of BRs have been studied in relative detail ( Singh et al., 2021 ; Chen et al., 2022 ), but Somatic embryogenesis (SE) involves the use of BRs, including their application effects and physiological and genetic mechanisms ( Kim and Moon, 2014 ; Chone et al., 2018 ; Zhao et al., 2022 ). Research has shown that BRs can regulate cell elongation by altering cell walls.…”