Different exogenous sugars affect the hormone signal pathway and sugar metabolism in “Red Globe” (Vitis vinifera L.) plantlets grown in vitro as shown by transcriptomic analysis

Abstract

Exogenously applied 2% fructose is the most appropriate carbon source that enhances photosynthesis and growth of grape plantlets compared with the same concentrations of sucrose and glucose. The role of the sugars was regulated by the expression of key candidate genes related to hormones, key metabolic enzymes, and sugar metabolism of grape plantlets ( Vitis vinifera L.) grown in vitro. The addition of sugars including sucrose, glucose, and fructose is known to be very helpful for the development of grape (V. vinifera L.) plantlets in vitro. However, the mechanisms by which these sugars regulate plant development and sugar metabolism are poorly understood. In grape plantlets, sugar metabolism and hormone synthesis undergo special regulation. In the present study, transcriptomic analyses were performed on grape (V. vinifera L., cv. Red Globe) plantlets in an in vitro system, in which the plantlets were grown in 2% each of sucrose (S20), glucose (G20), and fructose (F20). The sugar metabolism and hormone synthesis of the plantlets were analyzed. In addition, 95.72-97.29% high-quality 125 bp reads were further analyzed out of which 52.65-60.80% were mapped to exonic regions, 13.13-28.38% to intronic regions, and 11.59-28.99% to intergenic regions. The F20, G20, and S20 displayed elevated sucrose synthase (SS) activities; relative chlorophyll contents; Rubisco activity; and IAA and zeatin (ZT) contents. We found F20 improved the growth and development of the plantlets better than G20 and S20. Sugar metabolism was a complex process, which depended on the balanced expression of key potential candidate genes related to hormones (TCP15, LOG3, IPT3, ETR1, HK2, HK3, CKX7, SPY, GH3s, MYBH, AGB1, MKK2, PP2C, PYL, ABF, SnRK, etc.), key metabolic enzymes (SUS, SPS, A/V-INV, and G6PDH), and sugar metabolism (BETAFRUCT4 and AMY). Moreover, sugar and starch metabolism controls the generation of plant hormone transduction pathway signaling molecules. Our dataset advances our knowledge of the genes involved in sugar metabolism and improves the understanding of complex regulatory networks involved in signal transduction in grape plantlets.

Regulatory roles of sugars in plant growth and development

“…Changes in sugar concentrations in plant tissues affect the expression of nuclear and plastid genes, although the latter generally react to sugars quite slowly [10,29,36]. Studies using DNA microarrays demonstrated both the stimulation and inhibition of several hundred different genes in response to exogenously administered glucose and sucrose, or sugar depletion, including regulation of transcription factors [20,22,29,46,69]. Glucose-regulated genes are involved in all the metabolic and growth processes, and in responses to stress factors [23].…”

Transcriptome Analysis Reveals Cotton (Gossypium hirsutum) Genes That Are Differentially Expressed in Cadmium Stress Tolerance

“…Many transcriptional factors expressed under Cd stress have been reported in previous studies, such as NAC, bHLH, WRKY, etc [35,36,37]. In this study, many unreported transcriptional factors were discovered, such as C3H, C2H2, Orphans, and MYB, etc, whereas C2H2 has been previously reported associated with osmotic stress in Arabidopsis thaliana [38].…”

Comparative Metabolomics Profiling Reveals Key Metabolites and Associated Pathways Regulating Tuber Dormancy in White Yam (<em>Dioscorea rotundata</em>)

“…The ratio of ABA quantity to GAs quantity in seeds or any other plant tissue that has capability of being dormant has been reported to be the determinant factor of the seed or tissue dormant status [7], and the effect of this factor (ABA/GAs ratio) surpasses the effect of any other factors and molecular processes that regulate dormancy in plant system. In maize, CYP01A26 was reported to exhibit ent-kaurene oxidase activity which led to increased accumulation bioactive GAs and consequently result in early seed dormancy break [128,129] Similarly, in rice, 13-hydroxylation pathway that involves the activity of 13-hydroxlases which were coded by CYP714b1 and CYP714B2 genes led to early seed germination [130]. We therefore infer that the activities of CYP1A2, CYP2C, CYP2J, CYP2EI, CYP3A4, found in linoleic acid metabolic pathway might have led to increase biosynthesis of GAs and activities of GAs in the tubers, led to dormancy break.…”