Antagonistic Effect of Sucrose Availability and Auxin on Rosa Axillary Bud Metabolism and Signaling, Based on the Transcriptomics and Metabolomics Analysis

Abstract

Shoot branching is crucial for successful plant development and plant response to environmental factors. Extensive investigations have revealed the involvement of an intricate regulatory network including hormones and sugars. Recent studies have demonstrated that two major systemic regulators—auxin and sugar—antagonistically regulate plant branching. However, little is known regarding the molecular mechanisms involved in this crosstalk. We carried out two complementary untargeted approaches—RNA-seq and metabolomics—on explant stem buds fed with different concentrations of auxin and sucrose resulting in dormant and non-dormant buds. Buds responded to the combined effect of auxin and sugar by massive reprogramming of the transcriptome and metabolome. The antagonistic effect of sucrose and auxin targeted several important physiological processes, including sink strength, the amino acid metabolism, the sulfate metabolism, ribosome biogenesis, the nucleic acid metabolism, and phytohormone signaling. Further experiments revealed a role of the TOR-kinase signaling pathway in bud outgrowth through at least downregulation of Rosa hybrida BRANCHED1 (RhBRC1). These new findings represent a cornerstone to further investigate the diverse molecular mechanisms that drive the integration of endogenous factors during shoot branching.

Glucose-6-Phosphate Dehydrogenases: The Hidden Players of Plant Physiology

“…Shoot branching is crucial for plant development and yield and is greatly dependent on the ability of axillary buds to grow out along the stem [82][83][84]. Bud outgrowth is very finely regulated by multiple endogenous (e.g., hormones, sugar) and exogenous (e.g., light, water stress) cues [85][86][87][88][89][90][91][92]. In this intricate regulation, sugars behave as signaling entities that promote bud outgrowth through several sugar signaling pathways corresponding to the trehalose 6P-, hexokinase-, glycolysis/tricarboxylic acid (TCA)-, and OPPP-dependent signaling pathways [83,93,94].…”

“…The authors of [94] first evidenced the role of the OPPP in sugar branching by demonstrating that the promotive effect of sucrose on bud outgrowth is repressed by 6-AN-an inhibitor of G6PDH-in Rosa sp. Molecular experiments conducted on in vitrocultured vegetative buds and on stably transformed Rosa calluses revealed that the OPPPdependent signaling pathway is involved in both sugar-mediated transcriptional (promoter level) and posttranscriptional (3 untranslated region) downregulation of Teosinte Branched 1/Branched1 (TB1/BRC1) [91,94,97]. BRC1 is the main inhibitor of shoot branching [98].…”

Uncovering the complex regulatory network of spring bud sprouting in tea plants: insights from metabolic, hormonal, and oxidative stress pathways

“…Glucose has been shown to repress the expression of CKX in Arabidopsis, leading to increased CKs accumulation, which promotes cell division and growth (Choudhary et al, 2022). Sucrose, on the other hand, impacts multiple metabolic pathways in axillary buds, including glycolysis, the TCA cycle, OPPP, and amino acid metabolism (Wang et al, 2022). High concentrations of sucrose have been shown to counteract the inhibitory effects of auxin on axillary buds and stimulate their growth while promoting bud dormancy by rapid transport from the apical meristem (Barbier et al, 2015).…”

Application of slow-controlled release fertilizer coordinates the carbon flow in carbon-nitrogen metabolism to effect rice quality

“…The changes in nitrogen and carbon supply can alter numerous central metabolites involved in carbon and nitrogen metabolism in parallel (Gao et al, 2020). To support the synthesis of amino acids and ensure adequate growth in rice grain, an appropriate nitrogen content is needed to drive the production of carbon skeletons and provide enough amino acids (Gutiérrez et al, 2007; Wang et al, 2022a).…”