Identification of the Eutrema salsugineum EsMYB90 gene important for anthocyanin biosynthesis

Abstract

Background: Anthocyanins contribute to coloration and antioxidation effects in different plant tissues. MYB transcription factors have been demonstrated to be a key regulator for anthocyanin synthesis in many plants. However, little information was available about the MYB genes in the halophyte species Eutrema salsugineum. Result: Here we report the identification of an important anthocyanin biosynthesis regulator EsMYB90 from Eutrema salsugineum, which is a halophyte tolerant to multiple abiotic stresses. Our phylogenetic and localization analyses supported that EsMYB90 is an R2R3 type of MYB transcription factor. Ectopic expression of EsMYB90 in tobacco and Arabidopsis enhanced pigmentation and anthocyanin accumulation in various organs. The transcriptome analysis revealed that 42 genes upregulated by EsMYB90 in 35S:EsMYB90 tobacco transgenic plants are required for anthocyanin biosynthesis. Moreover, our qRT-PCR results showed that EsMYB90 promoted expression of early (PAL, CHS, and CHI) and late (DFR, ANS, and UFGT) anthocyanin biosynthesis genes in stems, leaves, and flowers of 35S:EsMYB90 tobacco transgenic plants. Conclusions: Our results indicated that EsMYB90 is a MYB transcription factor, which regulates anthocyanin biosynthesis genes to control anthocyanin biosynthesis. Our work provides a new tool to enhance anthocyanin production in various plants.

The BBX gene family in Moso bamboo (Phyllostachys edulis): identification, characterization and expression profiles

“…The phenylpropanoid/flavonoid biosynthesis pathway is an important metabolic pathway in plants. For example, plant defense responses are associated with activation of the general phenylpropanoid pathway and anthocyanins are the end product of a branch of the phenylpropanoid/flavonoid biosynthesis pathway [ 74 , 75 ]. It has been shown that BBX proteins not only play an essential role in regulating photomorphogenesis [ 76 ], but also light-induced anthocyanin synthesis.…”

Integrated Metabolomic and Transcriptomic Analysis Reveals the Flavonoid Regulatory Network by Eutrema EsMYB90

“…The increased anthocyanin content in leaves, stems, flowers and fruit pods of EsMYB90 transgenic tobacco plants was caused by significantly up-regulated expression of anthocyanin biosynthesis genes in the previous study [37]. In order to clarify in depth Except for the above flavonoid metabolites, the contents of caffeic acid in hydroxycinnamoyl derivatives, 3-O-p-coumaroyl shikimic acid O-hexoside as well as chlorogenic acid methyl ester in quinate derivatives, esculetin (6,7-dihydroxycoumarin) and esculetin O-quinacyl esculetin O-quinic acid in coumarin also strongly increased (Figure 2A and Supplementary Table S3).…”

“…The increased anthocyanin content in leaves, stems, flowers and fruit pods of Es-MYB90 transgenic tobacco plants was caused by significantly up-regulated expression of anthocyanin biosynthesis genes in the previous study [37]. In order to clarify in depth the specific roles of EsMYB90 in flavonoid pathways and unravel the regulatory mechanisms in place, we have performed the combined analysis of significantly differential metabolites and markedly differential expression genes (DEGs).…”

“…In our previous study, we demonstrated that ectopic expression of Eutrema EsMYB90 (p35S:EsMYB90) in tobacco led to purplish red at varying degrees in leaves, stem, flowers and fruit pods and was accompanied with a strongly elevated anthocyanin level [37]. To further understand and define the regulating effect of the EsMYB90 gene on different pigments and flavonoid compounds, the contents of anthocyanin, chlorophyll, proanthocyanin (PA) and total flavonoid were checked in EsMYB90 transgenic tobacco and wild type plants.…”

“…In Arabidopsis, AtMYB75, AtMYB90, AtMYB113 and AtMYB114 mainly regulate the expression of late biosynthesis genes (LBGs) [5,32]. However, Eutrema EsMYB90 is not only involved in regulating the expression of LBGs (DFR, ANS/LDOX and UFGT) but also in promoting the expression of anthocyanin early biosynthesis genes (EBGs) such as PAL, CHS, CHI and F3H in 35S:EsMYB90 tobacco transgenic plants [37]. Additionally, Arabidopsis AtMYB75, AtMYB90, AtMYB113 and AtMYB114 function redundantly in participating in the MYB-bHLH-WD40 (MBW) complex to regulate anthocyanin and proanthocyanidin (PA) biosynthesis, and at least four MBW complexes assembled with various MYBs were involved in PA accumulation of the innermost cell layer in an Arabidopsis seed coat [2,52].…”