Transcriptome profiling reveals candidate flavonol-related genes of Tetrastigma hemsleyanum under cold stress

Abstract

Background Tetrastigma hemsleyanum Diels et Gilg is a valuable medicinal herb, whose main bioactive constituents are flavonoids. Chilling sensitivity is the dominant environmental factor limiting growth and development of the plants. But the mechanisms of cold sensitivity in this plant are still unclear. Also, not enough information on genes involved in flavonoid biosynthesis in T. hemsleyanum is available to understand the mechanisms of its physiological and pharmaceutical effects. Results The electrolyte leakage, POD activity, soluble protein, and MDA content showed a linear sustained increase under cold stress. The critical period of cold damage in T. hemsleyanum was from 12 h to 48 h. Expression profiles revealed 18,104 differentially expressed genes (DEGs) among these critical time points. Most of the cold regulated DEGs were early-response genes. A total of 114 unigenes were assigned to the flavonoid biosynthetic pathway. Fourteen genes most likely to encode flavonoid biosynthetic enzymes were identified. Flavonols of T. hemsleyanum might play a crucial role in combating cold stress. Genes encoding P AL, 4CL , CHS, ANR, FLS , and LAR were significantly up-regulated by cold stress, which could result in a significant increase in crucial flavonols (catechin, epicatechin, rutin, and quercetin) in T. hemsleyanum. Conclusions Overall, our results show that the expression of genes related to flavonol biosynthesis as well as flavonol content increased in T. hemsleyanum under cold stress. These findings provide valuable information regarding the transcriptome changes in response to cold stress and give a clue for identifying candidate genes as promising targets that could be used for improving cold tolerance via molecular breeding. The study also provides candidate genes involved in flavonoid biosynthesis and may be useful for clarifying the biosynthetic pathway of flavonoids in T. hemsleyanum . Electronic supplementary material The online version of this article (10.1186/s12864-019-6045-y) contains supplementary material, which is available to authorized users.

Transcriptomic Analysis Reveals the Mechanism of Picea crassifolia Survival for Alpine Treeline Condition

“…Our study showed that half of these genes were upregulated, indicating their roles in the resistance to cold stress and UV stress at higher elevations. Meanwhile, the increase of elevations also significantly promoted the transcript of anthocyanin downstream pathway genes, including 3 DFRs (dihydroflavonol-4-reductase), 1 UFGT (anthocyanidin 3-O-glucosyltransferas), and 1 ANR (anthocyanidin reductase), and these would contribute to the resistance of trees to UV or other stresses [57]. Therefore, the present study results indicated that flavonoids might play an important role in the survival of P. crassifoliain in the alpine environment.…”

“…Flavonoids are a large class of plant secondary metabolites that exert diverse biological and pharmacological effects, including the protection of plants against abiotic stresses [57]. With respect to enzymatic coding genes involved in the flavonoid or anthocyanin biosynthetic pathway, in this study, 12 of the 29 DEGs were upregulated at different elevations.…”

“…With respect to enzymatic coding genes involved in the flavonoid or anthocyanin biosynthetic pathway, in this study, 12 of the 29 DEGs were upregulated at different elevations. For example, F3Hs and F3 5 Hs, encoding flavanone 3-hydroxylases and flavonoid 3 ,5 -hydroxylase, respectively, are involved in an early step in flavonoid metabolism leading to the formation of dihydroflavonols from flavanones [57,58]. In grape berries, UV-B increases the expression of these two genes, resulting in increased flavonol and anthocyanin content [59].…”

Co-regulation role of endogenous hormones and transcriptomics profiling under cold stress in Tetrastigma hemsleyanum

“…In previous research, we measured the phenotypes and some physiological and biochemical indexes, such as the electrolyte leakage, POD activity, soluble protein, and MDA content [13]. Our results showed that the 0 °C exposure was the optimum treatment temperature.…”

Co-regulation role of endogenous hormones and transcriptomics profiling under cold stress in Tetrastigma hemsleyanum

“…Healthy sterile test-tube plantlets of T. hemsleyanum were obtained and cultured as the same as our previous report [57]. Based on our preliminary work results of physiological parameters determination, the temperature and sampling time of cold stress treatment were optimized [13]. For both the control and cold stress tests, these seedlings were cultured in the same conditions except the different temperatures at 25 °C or 0 °C.…”