Anthocyanin Degrading and Chlorophyll Accumulation Lead to the Formation of Bicolor Leaf in Ornamental Kale

Ornamental kale is a popular decorative plant. We identified a peculiar bicolor leaf double haploid line, with green margins and red centers. The development of bicolor leaves can be divided into three stages: S1, S2, and S3. To probe the reason for bicolor formation, we analyzed the anthocyanin and chlorophyll contents, detected the changes in indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellin 3 (GA3), sugar, and starch contents, and identified the differentially expressed genes (DEGs) using RNA-seq. Results showed that the bicolor leaf phenotype is gradually formed with anthocyanin degrading and chlorophyll accumulation. Anthocyanin content is lower in the green margin (S3_S) than in the red center (S3_C) part at S3. IAA content was positively correlated with anthocyanin content during the bicolor leaf development. During anthocyanin degrading from S1 to S2, cinnamate-4-hydroxylase (C4H) and transport inhibitor response 1 (TIR1) were downregulated, while lateral organ boundaries domain 39 (LBD39) was upregulated. Two peroxidases, two β-glucosidases (BGLU), LBD39, LBD37, detoxifying efflux carrier 35 (DTX35), three no apical meristem (NAC) transcription factors (TFs), and 15 WRKY DNA-binding protein (WRKY) TFs were downregulated in S3_S vs. S3_C. The bicolor phenotype was mainly linked to anthocyanin degrading and chlorophyll accumulation, and that anthocyanin degrading resulted from reduced anthocyanin biosynthesis and increased anthocyanin degradation.

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Transcriptome analyses reveal anthocyanin biosynthesis in eggplants

10.7287/peerj.preprints.27289 ◽

2018 ◽

Author(s):

Xi Ou Xiao ◽

Wen qiu Lin ◽

Ke Li ◽

Xue Feng Feng ◽

Hui Jin ◽

...

Keyword(s):

Anthocyanin Biosynthesis ◽

Negative Regulation ◽

Anthocyanin Content ◽

Biosynthesis Pathway ◽

Rna Seq ◽

Wild Type ◽

Rt Pcr ◽

Total Anthocyanin ◽

Total Anthocyanin Content ◽

Cumulative Knowledge

We obtained a white-peel eggplant (L6-5) by EMS mutation in our previous study, whose total anthocyanin content was significantly decreased as compared with that of wild-type (WT). To analyse the anthocyanin biosynthesis mechanism in eggplants, we analysed the eggplant peel by RNA-seq in this study. The transcript results revealed upregulation of 465 genes and downregulation of 525 genes in L6-5 as compared with the WT eggplant. A total of 11 anthocyanin biosynthesis structure genes were significantly downregulated in L6-5 as compared with that in WT. Meanwhile, on the basis of the RT-PCR results of four natural eggplant cultivars, the expression pattern of 11 anthocyanin biosynthesis structure genes was consistent with the anthocyanin content. Thus, we speculated the anthocyanin biosynthesis pathway in eggplant peel. The transcript and RT-PCR results suggested positive regulation of MYB1, MYB108 and TTG8 and negative regulation of bHLH36 in anthocyanin biosynthesis. This study enhanced our cumulative knowledge about anthocyanin biosynthesis in eggplant peels.

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Simultaneous changes in anthocyanin, chlorophyll, and carotenoid contents produce green variegation in pink–leaved ornamental kale

BMC Genomics ◽

10.1186/s12864-021-07785-x ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Yang Liu ◽

Xin Feng ◽

Yuting Zhang ◽

Fuhui Zhou ◽

Pengfang Zhu

Keyword(s):

Molecular Mechanisms ◽

Color Change ◽

Anthocyanin Biosynthesis ◽

Carotenoid Biosynthesis ◽

Anthocyanin Content ◽

Leaf Color ◽

Chlorophyll Metabolism ◽

Leaf Coloration ◽

New Varieties ◽

Ornamental Kale

Abstract Background Anthocyanin, chlorophyll, and carotenoid pigments are widely distributed in plants, producing various colors. Ornamental kale (Brassica oleracea var. acephala DC) which has colorful inner leaves is an ideal plant to explore how these three pigments contribute to leaf color. The molecular mechanisms of the coloration in ornamental kale could provide reference for exploring the mechanisms of pigmentation in other plants. Results In this study, we sequenced the transcriptome and determined the pigment contents of an unusual cultivar of ornamental kale with three different types of leaf coloration: pink (C3), light pink (C2), and variegated pink–green (C1). A total of 23,965 differentially expressed genes were detected in pairwise comparisons among the three types of leaves. The results indicate that Bo9g058630 coding dihydroflavonol 4–reductase (DFR) and Bo3g019080 coding shikimate O–hydroxycinnamoyltransferase (HCT) acted in anthocyanin biosynthesis in pink leaves. Bo1g053420 coding pheophorbidase (PPD) and Bo3g012430 coding 15–cis–phytoene synthase (crtB) were identified as candidate genes for chlorophyll metabolism and carotenoid biosynthesis, respectively. The transcription factors TT8, MYBL2, GATA21, GLK2, and RR1 might participate in triggering the leaf color change in ornamental kale. Anthocyanin content was highest in C3 and lowest in C1. Chlorophyll and carotenoid contents were lowest in C2 and highest in C1. Conclusions Based on these findings, we suspected that the decrease in anthocyanin biosynthesis and the increase in chlorophyll and carotenoid biosynthesis might be the reason for the leaf changing from pink to variegate pink–green in this unusual cultivar. Our research provides insight into the molecular mechanisms of leaf coloration in ornamental kale, contributing to a theoretical foundation for breeding new varieties.

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PbLAC4-like, activated by PbMYB26, related to the degradation of anthocyanin during color fading in pear

BMC Plant Biology ◽

10.1186/s12870-021-03220-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Guangping Zhao ◽

Fangxin Xiang ◽

Shichao Zhang ◽

Junxing Song ◽

Xieyu Li ◽

...

Keyword(s):

Anthocyanin Biosynthesis ◽

Degradation Mechanism ◽

Vital Role ◽

Luciferase Assay ◽

Anthocyanin Content ◽

Enzyme Activity Assay ◽

Red Color ◽

Color Fading ◽

Degradation Ability ◽

Anthocyanin Degradation

Abstract Background Decrease in anthocyanin content results in the loss of red color in leaves, petals and receptacles during development. The content of anthocyanin was affected by the biosynthesis and degradation of anthocyanin. Compared with the known detailed mechanism of anthocyanin biosynthesis, the degradation mechanism is not fully investigated. It is vital to study the degradation mechanism of anthocyanin in pear for promoting the accumulation of anthocyanin and inhibiting the red fading in pear. Results Here, we reported that laccase encoded by PbLAC4-like was associated with anthocyanin degradation in pear. The expression pattern of PbLAC4-like was negatively correlated with the content of anthocyanin during the color fading process of pear leaves, petals and receptacles. Phylogenetic analysis and sequence alignment revealed that PbLAC4-like played a vital role in anthocyanin degradation. Thus, the degradation of anthocyanin induced by PbLAC4-like was further verified by transient assays and prokaryotic expression. More than 80% of anthocyanin compounds were degraded by transiently over-expressed PbLAC4-like in pear fruitlet peel. The activity of crude enzyme to degrade anthocyanin in leaves at different stages was basically consistent with the expression of PbLAC4-like. The anthocyanin degradation ability of prokaryotic induced PbLAC4-like protein was also verified by enzyme activity assay. Besides, we also identified PbMYB26 as a positive regulator of PbLAC4-like. Yeast one-hybrid and dual luciferase assay results showed that PbMYB26 activated PbLAC4-like expression by directly binding to the PbLAC4-like promoter. Conclusions Taken together, the PbLAC4-like activated by PbMYB26, was involved in the degradation of anthocyanin, resulting in the redness fading in different pear tissues.

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Transcriptional analysis reveals key insights into seasonal induced anthocyanin degradation and leaf color transition in purple tea (Camellia sinensis (L.) O. Kuntze)

Scientific Reports ◽

10.1038/s41598-020-80437-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tony Kipkoech Maritim ◽

Mamta Masand ◽

Romit Seth ◽

Ram Kumar Sharma

Keyword(s):

Anthocyanin Biosynthesis ◽

Transcriptome Assembly ◽

Lac Repressor ◽

Transcriptional Analysis ◽

Anthocyanin Content ◽

Leaf Color ◽

Total Anthocyanin ◽

Color Transition ◽

Production Period ◽

Anthocyanin Degradation

AbstractPurple-tea, an anthocyanin rich cultivar has recently gained popularity due to its health benefits and captivating leaf appearance. However, the sustainability of purple pigmentation and anthocyanin content during production period is hampered by seasonal variation. To understand seasonal dependent anthocyanin pigmentation in purple tea, global transcriptional and anthocyanin profiling was carried out in tea shoots with two leaves and a bud harvested during in early (reddish purple: S1_RP), main (dark gray purple: S2_GP) and backend flush (moderately olive green: S3_G) seasons. Of the three seasons, maximum accumulation of total anthocyanin content was recorded in S2_GP, while least amount was recorded during S3_G. Reference based transcriptome assembly of 412 million quality reads resulted into 71,349 non-redundant transcripts with 6081 significant differentially expressed genes. Interestingly, key DEGs involved in anthocyanin biosynthesis [PAL, 4CL, F3H, DFR and UGT/UFGT], vacuolar trafficking [ABC, MATE and GST] transcriptional regulation [MYB, NAC, bHLH, WRKY and HMG] and Abscisic acid signaling pathway [PYL and PP2C] were significantly upregulated in S2_GP. Conversely, DEGs associated with anthocyanin degradation [Prx and lac], repressor TFs and key components of auxin and ethylene signaling pathways [ARF, AUX/IAA/SAUR, ETR, ERF, EBF1/2] exhibited significant upregulation in S3_G, correlating positively with reduced anthocyanin content and purple coloration. The present study for the first-time elucidated genome-wide transcriptional insights and hypothesized the involvement of anthocyanin biosynthesis activators/repressor and anthocyanin degrading genes via peroxidases and laccases during seasonal induced leaf color transition in purple tea. Futuristically, key candidate gene(s) identified here can be used for genetic engineering and molecular breeding of seasonal independent anthocyanin-rich tea cultivars.

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Anthocyanin Production and Enzymatic Degradation during the Development of Dark Purple and Lilac Paprika Fruit

Journal of the American Society for Horticultural Science ◽

10.21273/jashs04727-19 ◽

2019 ◽

Vol 144 (5) ◽

pp. 329-338

Author(s):

Yuji Yamada ◽

Masayoshi Nakayama ◽

Hiromitsu Shibata ◽

Sanae Kishimoto ◽

Takashi Ikeda

Keyword(s):

High Performance ◽

Color Change ◽

Anthocyanin Biosynthesis ◽

Green Pigment ◽

Chlorophyll Contents ◽

Degradation Activity ◽

Purple Coloration ◽

Anthocyanin Production ◽

Hplc Analyses ◽

Anthocyanin Degradation

During development, the fruit of some paprika (Capsicum annuum L.) cultivars shows a change in color from green to dark purple (e.g., ‘Mavras’) or lilac (e.g., ‘Tequila’). However, this purple coloration is rare among paprika cultivars and disappears in ripened fruit, which are red. Therefore, we investigated the mechanism causing this color change in the cultivars Mavras and Tequila to better understand how purple ripened fruit could be generated. High-performance liquid chromatography (HPLC) analyses of the anthocyanin contents of the fruit indicated that anthocyanin was undetectable in green fruit, accumulated in dark purple or lilac ones, and then decreased again in red ones in both cultivars. Furthermore, expressions of most of the analyzed anthocyanin biosynthesis–related genes and genes for their transcription factors increased in dark purple or lilac fruit and decreased in red ones, i.e., it was synchronized with the changes in anthocyanin contents. Furthermore, anthocyanin degradation activity as a result of peroxidases was detected at all stages but increased when the lilac or dark purple color started to fade. Thus, the development of purple coloration is caused by increased anthocyanin biosynthesis, whereas the fading of this coloration is a result of both a decrease in anthocyanin biosynthesis and an increase in anthocyanin degradation. At the ripening stage, the green pigment (chlorophyll) contents decreased, whereas the red pigment (carotenoid, particularly capsanthin) contents increased. However, these timings did not completely coincide with the timing of anthocyanin degradation, suggesting that the content of each pigment is individually regulated, and so purple, green, and red coloration could be freely expressed in mature paprika fruit.

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Transcriptome analyses reveal anthocyanin biosynthesis in eggplants

10.7287/peerj.preprints.27289v1 ◽

2018 ◽

Author(s):

Xi Ou Xiao ◽

Wen qiu Lin ◽

Ke Li ◽

Xue Feng Feng ◽

Hui Jin ◽

...

Keyword(s):

Anthocyanin Biosynthesis ◽

Negative Regulation ◽

Anthocyanin Content ◽

Biosynthesis Pathway ◽

Rna Seq ◽

Wild Type ◽

Rt Pcr ◽

Total Anthocyanin ◽

Total Anthocyanin Content ◽

Cumulative Knowledge

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Identification of R2R3-MYB gene family reveal candidate genes for anthocyanin biosynthesis in Lonicera caerulea fruit based on RNA-seq data

Journal of Berry Research ◽

10.3233/jbr-210008 ◽

2021 ◽

pp. 1-19

Author(s):

Huixin Gang ◽

Qian Zhang ◽

Jing Chen ◽

Dong Qin ◽

Junwei Huo

Keyword(s):

Candidate Genes ◽

Molecular Mechanisms ◽

Anthocyanin Biosynthesis ◽

Expression Profiles ◽

Myb Transcription Factor ◽

Anthocyanin Content ◽

Rna Seq ◽

Lonicera Caerulea ◽

Conserved Sequence ◽

R2r3 Myb

BACKGROUND: R2R3-MYB transcription factor (TF) family plays important roles in various biological processes in many plants, especially in the regulation of plant flavonoid accumulation. The fruit of Lonicera caerulea contains abundant anthocyanin. OBJECTIVE: The R2R3-MYB TF family was systematically analyzed according to the RNA-seq data, and the R2R3-MYB candidate genes that were involved in anthocyanin biosynthesis in the fruit of Lonicera caerulea were screened. METHODS: The R2R3-MYB TFs in Lonicera caerulea were identified, and the physical and chemical properties, protein conserved sequence alignment and motifs of each R2R3-MYB TFs were analyzed using bioinformatics methods. The expression levels of these genes and anthocyanin levels in different tissues and different developmental stages of fruit were determined by RT-qPCR and pH shift method. RESULTS: A total of 59 genes encoding R2R3-MYB TFs in Lonicera caerulea were identified and clustered into 20 subgroups (C1 to C20) based on the relationship to AtR2R3-MYBs. Expression profiles showed that the expression of CL6086 and CL552 in fruit were higher than other tissues, and upregulated in the veraison fruit compared to the green ripe fruit. As the expression of the two genes was concurrent with the anthocyanin content, and showed high correlation with anthocyanin biosynthetic structural genes, they were considered as closely related to anthocyanin biosynthesis in the fruit. CONCLUSION: The results provide a systematic analysis of LcR2R3-MYBs, and the foundation for further molecular mechanisms research of anthocyanin biosynthesis regulated by R2R3-MYB in the fruit of Lonicera caerulea.

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Discovery of genes involved in anthocyanin biosynthesis from the rind and pith of three sugarcane varieties using integrated metabolic profiling and RNA-seq analysis

BMC Plant Biology ◽

10.1186/s12870-021-02986-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yang Ni ◽

Haimei Chen ◽

Di Liu ◽

Lihui Zeng ◽

Pinghua Chen ◽

...

Keyword(s):

Candidate Genes ◽

Anthocyanin Biosynthesis ◽

Raw Materials ◽

Saccharum Officinarum ◽

Anthocyanin Content ◽

Rna Seq ◽

Sugarcane Varieties ◽

Phenylpropanoid Biosynthesis ◽

Localization Analysis ◽

Main Components

Abstract Background Sugarcane (Saccharum officinarum) is one of the most valuable feedstocks for sugar production. In addition to the production of industrial raw materials such as alcohol, papermaking, the fiber of livestock feed, respectively, sugarcane can produce bioactive compounds such as anthocyanins. Elucidation of the anthocyanin biosynthesis pathway is critical for the molecular breeding of sugarcane varieties with favorable traits. We aimed to identify candidate genes involved in anthocyanin biosynthesis by transcriptomic and metabolomic analyses. Results Three varieties of sugarcane displaying different colors were used in this study: FN15 (greed rind), ROC22 (red rind), and Badila (purple rind). Sample materials were subjected to metabolomic analysis using UPLC-Q-TOF/MS and RNA-seq analysis. The metabolomic profiling results showed Cyanidin, Cyanidin (6’-malonylglucoside), Cyanidin O-glucoside, and Peonidin O-glucoside were the main components responsible for the rind color. Then, through RNA-seq analysis, we identified a total of 3137, 3302, 3014 differentially expressed genes (DEGs) between the rind and pith tissues for the corresponding varieties Badila rind, ROC22, and FN15. We then compared the expression levels of genes among the rind tissues from the three varieties. We identified 2901, 2821, and 3071 DEGs between Badila rind vs. ROC22 rind, Badila rind vs. FN15 rind, ROC22 rind vs. FN15 rind, respectively. We identified two enriched pathways, including phenylpropanoid biosynthesis and flavonoid biosynthesis. Sequencing similarity search identified a total of 50 unigenes belonging to 15 enzyme families as putative genes involved in anthocyanin biosynthesis in sugarcane rind. Seven of them were identified as candidate genes related to anthocyanin biosynthesis in the rind of sugarcane through co-localization analysis with the anthocyanin content in sugarcane. In total, 25 unigenes were selected and subjected to RT-qPCR analysis, and qRT-PCR results were consistent with those obtained with the RNA-Seq experiments. Conclusions We proposed a pathway for anthocyanin biosynthesis in sugarcane rind. This is the first report on the biosynthesis of anthocyanin in sugarcane using the combined transcriptomic and metabolomic methods. The results obtained from this study will lay the foundation for breeding purple pith sugarcane varieties with high anthocyanin contents.

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The Purple Leaf (pl6) Mutation Regulates Leaf Color by Altering the Anthocyanin and Chlorophyll Contents in Rice

Plants ◽

10.3390/plants9111477 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1477

Author(s):

Asadullah Khan ◽

Sanaullah Jalil ◽

Huan Cao ◽

Yohannes Tsago ◽

Mustapha Sunusi ◽

...

Keyword(s):

Gamma Ray ◽

Anthocyanin Biosynthesis ◽

Light Attenuation ◽

Transcript Level ◽

Underlying Mechanism ◽

Anthocyanin Accumulation ◽

Morphological Marker ◽

Chlorophyll Contents ◽

Rice Mutant ◽

Purple Coloration

The anthocyanin biosynthesis attracts strong interest due to the potential antioxidant value and as an important morphological marker. However, the underlying mechanism of anthocyanin accumulation in plant tissues is not clearly understood. Here, a rice mutant with a purple color in the leaf blade, named pl6, was developed from wild type (WT), Zhenong 41, with gamma ray treatment. By map-based cloning, the OsPL6 gene was located on the short arm of chromosome 6. The multiple mutations, such as single nucleotide polymorphism (SNP) at −702, −598, −450, an insertion at −119 in the promoter, three SNPs and one 6-bp deletion in the 5′-UTR region, were identified, which could upregulate the expression of OsPL6 to accumulate anthocyanin. Subsequently, the transcript level of structural genes in the anthocyanin biosynthesis pathway, including OsCHS, OsPAL, OsF3H and OsF3′H, was elevated significantly. Histological analysis revealed that the light attenuation feature of anthocyanin has degraded the grana and stroma thylakoids, which resulted in poor photosynthetic efficiency of purple leaves. Despite this, the photoabatement and antioxidative activity of anthocyanin have better equipped the pl6 mutant to minimize the oxidative damage. Moreover, the contents of abscisic acid (ABA) and cytokanin (CK) were elevated along with anthocyanin accumulation in the pl6 mutant. In conclusion, our results demonstrate that activation of OsPL6 could be responsible for the purple coloration in leaves by accumulating excessive anthocyanin and further reveal that anthocyanin acts as a strong antioxidant to scavenge reactive oxygen species (ROS) and thus play an important role in tissue maintenance.

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The MIR-Domain of PbbHLH2 Is Involved in Regulation of the Anthocyanin Biosynthetic Pathway in ”Red Zaosu” (PyrusBretschneideri Rehd.) Pear Fruit

International Journal of Molecular Sciences ◽

10.3390/ijms22063026 ◽

2021 ◽

Vol 22 (6) ◽

pp. 3026

Author(s):

Xieyu Li ◽

Fangxin Xiang ◽

Wei Han ◽

Bingqing Qie ◽

Rui Zhai ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Anthocyanin Biosynthesis ◽

Bimolecular Fluorescence Complementation ◽

Anthocyanin Content ◽

Pear Fruit ◽

Fruit Peel ◽

Interaction Domain ◽

Dihydroflavonol Reductase ◽

Anthocyanin Biosynthetic Pathway ◽

R2r3 Myb

The N-terminal of Myc-like basic helix-loop-helix transcription factors (bHLH TFs) contains an interaction domain, namely the MYB-interacting region (MIR), which interacts with the R2R3-MYB proteins to regulate genes involved in the anthocyanin biosynthetic pathway. However, the functions of MIR-domain bHLHs in this pathway are not fully understood. In this study, PbbHLH2 containing the MIR-domain was identified and its function investigated. The overexpression of PbbHLH2 in ”Zaosu” pear peel increased the anthocyanin content and the expression levels of late biosynthetic genes. Bimolecular fluorescence complementation showed that PbbHLH2 interacted with R2R3-MYB TFs PbMYB9, 10, and 10b in onion epidermal cells and confirmed that MIR-domain plays important roles in the interaction between the MIR-domain bHLH and R2R3-MYB TFs. Moreover, PbbHLH2 bound and activated the dihydroflavonol reductase promoter in yeast one-hybrid (Y1H) and dual-luciferase assays. Taken together these results suggested that the MIR domain of PbbHLH2 regulated anthocyanin biosynthesis in pear fruit peel.

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