scholarly journals The Effects of Ultraviolet A/B Treatments on Anthocyanin Accumulation and Gene Expression in Dark-Purple Tea Cultivar ‘Ziyan’ (Camellia sinensis)

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 354 ◽  
Author(s):  
Wei Li ◽  
Liqiang Tan ◽  
Yao Zou ◽  
Xiaoqin Tan ◽  
Jiacheng Huang ◽  
...  

‘Ziyan’ is a novel anthocyanin-rich tea cultivar with dark purple young shoots. However, how its anthocyanin accumulation is affected by environmental factors, such as ultraviolet (UV), remains unclear. In this study, we observed that UV light treatments stimulated anthocyanin accumulation in ‘Ziyan’ leaves, and we further analyzed the underlying mechanisms at gene expression and enzyme activity levels. In addition, the catechins and chlorophyll contents of young shoots under different light treatments were also changed. The results showed that the contents of total anthocyanins and three major anthocyanin molecules, i.e., delphinidin, cyanidin, and pelargonidin, were significantly higher in leaves under UV-A, UV-B, and UV-AB treatments than those under white light treatment alone. However, the total catechins and chlorophyll contents in these purple tea plant leaves displayed the opposite trends. The anthocyanin content was the highest under UV-A treatment, which was higher by about 66% than control. Compared with the white light treatment alone, the enzyme activities of chalcone synthase (CHS), flavonoid 3′,5′-hydroxylase (F3′5′H), and anthocyanidin synthase (ANS) under UV treatments increased significantly, whereas the leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) activities reduced. There was no significant difference in dihydroflavonol 4-reductase (DFR) activity under all treatments. Comparative transcriptome analyses unveiled that there were 565 differentially expressed genes (DEGs) of 29,648 genes in three pair-wise comparisons (white light versus UV-A, W vs. UV-A; white light versus UV-B, W vs. UV-A; white light versus UV-AB, W vs. UV-AB). The structural genes in anthocyanin pathway such as flavanone 3-hydroxylase (F3H), F3′5′H, DFR, and ANS, and regulatory gene TT8 were upregulated under UV-A treatment; F3′5′H, DFR, ANS, and UFGT and regulatory genes EGL1 and TT2 were upregulated under UV-AB treatment. However, most structural genes involved in phenylpropanoid and flavonoid pathways were downregulated under UV-B treatment compared with control. The expression of LAR and ANR were repressed in all UV treatments. Our results indicated that UV-A and UV-B radiations can induce anthocyanin accumulation in tea plant ‘Ziyan’ by upregulating the structural and regulatory genes involved in anthocyanin biosynthesis. In addition, UV radiation repressed the expression levels of LAR, ANR, and FLS, resulting in reduced ANR activity and a metabolic flux shift toward anthocyanin biosynthesis.

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1477
Author(s):  
Asadullah Khan ◽  
Sanaullah Jalil ◽  
Huan Cao ◽  
Yohannes Tsago ◽  
Mustapha Sunusi ◽  
...  

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.


2021 ◽  
Author(s):  
Shikai Zhang ◽  
Wang Zhan ◽  
Anran Sun ◽  
Ying Xie ◽  
Zhiming Han ◽  
...  

Abstract The red color formation of Acer mandshuricum leaves is caused by the accumulation of anthocyanins primarily, but the molecular mechanism researches which underlie anthocyanin biosynthesis in A. mandshuricum were still lacking. Therefore, we combined the transcriptome and metabolome and analyzed the regulatory mechanism and accumulation pattern of anthocyanins in leaf color change periods in three different leaf color states. In our results, 26 anthocyanins were identified. Notably, the metabolite cyanidin 3-O-glucoside was found that significantly correlated with the color formation, was the predominant metabolite in anthocyanin biosynthesis of A. mandshuricum. By the way, two key structural genes ANS (Cluster-20561.86285) and BZ1 (Cluster-20561.99238) in anthocyanidin biosynthesis pathway were significantly up-regulated in RL, suggesting that they might enhance accumulation of cyanidin 3-O-glucoside which is their downstream metabolite, and contributed the red formation of A. mandshuricum leaves. Additionally, most TFs (e.g., MYBs, bZIPs and bHLHs) were detected differentially expressed in three leaf color stages that could participate in anthocyanin accumulation. This study sheds light on the anthocyanin molecular regulation of anthocyanidin bio-synthesis and accumulation underlying the different leaf color change periods in A. mandshuricum, and it could provide basic theory and new insight for the leaf color related genetic improvement of A. mandshuricum.


Plant Disease ◽  
2017 ◽  
Vol 101 (9) ◽  
pp. 1606-1615 ◽  
Author(s):  
Zhen-Hua Cui ◽  
Wen-Lu Bi ◽  
Xin-Yi Hao ◽  
Peng-Min Li ◽  
Ying Duan ◽  
...  

Reddish-purple coloration on the leaf blades and downward rolling of leaf margins are typical symptoms of grapevine leafroll disease (GLD) in red-fruited grapevine cultivars. These typical symptoms are attributed to the expression of genes encoding enzymes for anthocyanins synthesis, and the accumulation of flavonoids in diseased leaves. Drought has been proven to accelerate development of GLD symptoms in virus-infected leaves of grapevine. However, it is not known how drought affects GLD expression nor how anthocyanin biosynthesis in virus-infected leaves is altered. The present study used HPLC to determine the types and levels of anthocyanins, and applied reverse transcription quantitative polymerase chain reaction (RT-qPCR) to analyze the expression of genes encoding enzymes for anthocyanin synthesis. Plantlets of Grapevine leafroll-associated virus 3 (GLRaV-3)-infected Vitis vinifera ‘Cabernet Sauvignon’ were grown in vitro under PEG-induced drought stress. HPLC found no anthocyanin-related peaks in the healthy plantlets with or without PEG-induced stress, while 11 peaks were detected in the infected plantlets with or without PEG-induced drought stress, but the peaks were significantly higher in infected drought-stressed plantlets. Increased accumulation of total anthocyanin compounds was related to the development of GLD symptoms in the infected plantlets under PEG stress. The highest level of up-regulated gene expression was found in GLRaV-3-infected leaves with PEG-induced drought stress. Analyses of variance and correlation of anthocyanin accumulation with related gene expression levels found that GLRaV-3-infection was the key factor in increased anthocyanin accumulation. This accumulation involved the up-regulation of two key genes, MYBA1 and UFGT, and their expression levels were further enhanced by drought stress.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shikai Zhang ◽  
Wang Zhan ◽  
Anran Sun ◽  
Ying Xie ◽  
Zhiming Han ◽  
...  

AbstractThe red color formation of Acer mandshuricum leaves is caused by the accumulation of anthocyanins primarily, but the molecular mechanism researches which underlie anthocyanin biosynthesis in A. mandshuricum were still lacking. Therefore, we combined the transcriptome and metabolome and analyzed the regulatory mechanism and accumulation pattern of anthocyanins in three different leaf color states. In our results, 26 anthocyanins were identified. Notably, the metabolite cyanidin 3-O-glucoside was found that significantly correlated with the color formation, was the predominant metabolite in anthocyanin biosynthesis of A. mandshuricum. By the way, two key structural genes ANS (Cluster-20561.86285) and BZ1 (Cluster-20561.99238) in anthocyanidin biosynthesis pathway were significantly up-regulated in RL, suggesting that they might enhance accumulation of cyanidin 3-O-glucoside which is their downstream metabolite, and contributed the red formation of A. mandshuricum leaves. Additionally, most TFs (e.g., MYBs, bZIPs and bHLHs) were detected differentially expressed in three leaf color stages that could participate in anthocyanin accumulation. This study sheds light on the anthocyanin molecular regulation of anthocyanidin biosynthesis and accumulation underlying the different leaf color change periods in A. mandshuricum, and it could provide basic theory and new insight for the leaf color related genetic improvement of A. mandshuricum.


2015 ◽  
Vol 140 (2) ◽  
pp. 129-135 ◽  
Author(s):  
John R. Stommel ◽  
Judith M. Dumm

Violet to black pigmentation of eggplant (Solanum melongena L.) fruit is caused by anthocyanin accumulation. Model systems demonstrate the role of regulatory genes in the control of anthocyanin biosynthesis. Anthocyanin structural gene transcription requires the expression of at least one member of each of three transcription factor families: MYB, MYC, and WD. To determine the molecular genetic basis for anthocyanin pigmentation in eggplant fruit, we used real-time polymerase chain reaction (PCR) to evaluate the expression of anthocyanin biosynthetic (Chs, Dfr, Ans) and regulatory (Myc, MybB, MybC, Wd) genes in S. melongena genotypes that produce fruit with dark violet (‘Classic’) or white (‘Ghostbuster’) coloration, respectively. Transcript levels and anthocyanin content were evaluated in fruit at various stages of development ranging from small post-anthesis fruit to full-sized marketable fruit. Anthocyanin content increased 9-fold in developing violet-colored ‘Classic’ fruit, whereas low but detectable concentrations were found in white ‘Ghostbuster’ fruit. Chs, Dfr, and Ans as well as MybC and Myc transcript levels were significantly higher in ‘Classic’ in comparison with ‘Ghostbuster’ fruit at comparable stages of fruit development with greatest differences observed for Ans transcript levels. MybC and Myc transcript levels increased in developing ‘Classic’ fruit coincident with increasing anthocyanin content. MybB and Wd transcript levels were not coordinated with changes in biosynthetic transcript levels or anthocyanin concentration.


2021 ◽  
Vol 11 ◽  
Author(s):  
Yun Zhao ◽  
Ting Min ◽  
Miaojin Chen ◽  
Hongxun Wang ◽  
Changqing Zhu ◽  
...  

Red coloration contributes to fruit quality and is determined by anthocyanin content in peach (Prunus persica). Our previous study illustrated that anthocyanin accumulation is strongly regulated by light, and the effect of induction differs according to light quality. Here we showed that both ultraviolet-A (UVA) and ultraviolet-B (UVB) irradiation promoted anthocyanin biosynthesis in “Hujingmilu” peach fruit, and a combination of UVA and UVB had additional effects. The expression of anthocyanin biosynthesis and light signaling related genes, including transcription factor genes and light signaling elements, were induced following UV irradiation as early as 6 h post-treatment, earlier than apparent change in coloration which occurred at 72 h. To investigate the molecular mechanisms for UVA- and UVB-induced anthocyanin accumulation, the genes encoding ELONGATED HYPOCOTYL 5 (HY5), CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1), Cryptochrome (CRY), and UV RESISTANCE LOCUS 8 (UVR8) in peach were isolated and characterized through functional complementation in corresponding Arabidopsis (Arabidopsis thaliana) mutants. PpHY5 and PpCOP1.1 restored hypocotyl length and anthocyanin content in Arabidopsis mutants under white light; while PpCRY1 and PpUVR8.1 restored AtHY5 expression in Arabidopsis mutants in response to UV irradiation. Arabidopsis PpHY5/hy5 transgenic lines accumulated higher amounts of anthocyanin under UV supplementation (compared with weak white light only), especially when UVA and UVB were applied together. These data indicated that PpHY5, acting as AtHY5 counterpart, was a vital regulator in UVA and UVB signaling pathway. In peach, the expression of PpHY5 was up-regulated by UVA and UVB, and PpHY5 positively regulated both its own transcription by interacting with an E-box in its own promoter, and the transcription of the downstream anthocyanin biosynthetic genes chalcone synthase 1 (PpCHS1), chalcone synthase 2 (PpCHS2), and dihydroflavonol 4-reductase (PpDFR1) as well as the transcription factor gene PpMYB10.1. In summary, functional evidence supports the role of PpHY5 in UVA and UVB light transduction pathway controlling anthocyanin biosynthesis. In peach this is via up-regulation of expression of genes encoding biosynthetic enzymes, as well as the transcription factor PpMYB10.1 and PpHY5 itself.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chunlan Piao ◽  
Jinguo Wu ◽  
Min-Long Cui

AbstractAnthocyanins are the largest group of water-soluble pigments and beneficial for human health. Although most plants roots have the potential to express natural biosynthesis pathways required to produce specialized metabolites such as anthocyanins, the anthocyanin synthesis is specifically silenced in roots. To explore the molecular mechanism of absence and production ability of anthocyanin in the roots, investigated the effect of a bHLH gene AmDelila, and an R2R3-MYB gene AmRosea1, which are the master regulators of anthocyanin biosynthesis in Antirrhinum majus flowers, by expressing these genes in transformed hairy roots of A. majus. Co-ectopic expression of both AmDelila and AmRosea1 significantly upregulated the expression of the key target structural genes in the anthocyanin biosynthesis pathway. Furthermore, this resulted in strongly enhanced anthocyanin accumulation in transformed hairy roots. Ectopic expression of AmDelila alone did not gives rise to any significant anthocyanin accumulation, however, ectopic expression of AmRosea1 alone clearly upregulated expression of the main structural genes as well as greatly promoted anthocyanin accumulation in transformed hairy roots, where the contents reached 0.773–2.064 mg/g fresh weight. These results suggest that AmRosea1 plays a key role in the regulatory network in controlling the initiation of anthocyanin biosynthesis in roots, and the combination of AmRosea1 and hairy root culture is a powerful tool to study and production of anthocyanins in the roots of A. majus.


2009 ◽  
Vol 134 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Hongmei Ma ◽  
Margaret Pooler ◽  
Robert Griesbach

Anthocyanin biosynthesis requires the coordinated expression of Myc, Wd, Chs, Dfr, and Myb. Chs and Dfr are structural genes, while Myc, Myb, and Wd are regulatory genes. Reverse transcription polymerase chain reaction was used to measure the expression of these genes in Phalaenopsis amabilis and Phalaenopsis schilleriana. P. amabilis expresses an albescent phenotype with petals and sepals that are anthocyanin free, while P. schilleriana has a wild-type phenotype with anthocyanin-containing petals and sepals. As expected, the petals and sepals of P. schilleriana expressed high levels of Chs and Dfr. The petals and sepals of P. amabilis expressed high levels of Chs and very low levels of Dfr. In P. amabilis and P. schilleriana, anthocyanin-specific Myc and Wd were expressed; however, Myb specific for anthocyanin biosynthesis were undetectable in P. amabilis. This suggests that the absence of Myb expression was responsible for the lack of dihydroflavonol 4-reductase and results in the absence of anthocyanin pigmentation in P. amabilis petals and sepals. This was confirmed by particle bombardment of P. amabilis petals with functional Mybs isolated from P. schilleriana. Comparisons of anthocyanin-related Myb gene expression between P. schilleriana and P. amabilis are between genetically different species. Phalaenopsis ‘Everspring Fairy’ expresses a harlequin phenotype with white petals and sepals containing large anthocyanin sectors. Harlequin flowers are ideal to evaluate anthocyanin-related Myb gene expression within genetically identical but differently pigmented tissue. High levels of anthocyanin-specific Myb and Dfr transcripts were present in the purple, but not in the white, sectors of Phalaenopsis ‘Everspring Fairy’ petals and sepals. There was no differential expression of Chs, Wd, and Myc between the purple and white sectors. These results are in agreement with the results from P. amabilis and P. schilleriana.


Genes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 81 ◽  
Author(s):  
Qiong He ◽  
Yanjing Ren ◽  
Wenbin Zhao ◽  
Ru Li ◽  
Lugang Zhang

To elucidate the effect of low temperature on anthocyanin biosynthesis in purple head Chinese cabbage, we analyzed anthocyanin accumulation and related gene expression in the seedlings of purple head Chinese cabbage, white head parent Chinese cabbage, and its purple male parent under a normal 25 °C temperature and a low 12 °C temperature. Anthocyanin accumulation in purple lines was strongly induced by low temperature, and the total anthocyanin content of seedlings was significantly enhanced. In addition, nearly all phenylpropanoid metabolic pathway genes (PMPGs) were down-regulated, some early biosynthesis genes (EBGs) were up-regulated, and nearly all late biosynthesis genes (LBGs) directly involved in anthocyanin biosynthesis showed higher expression levels in purple lines after low-temperature induction. Interestingly, a R2R3-MYB transcription factor (TF) gene ‘BrMYB2’ and a basic-helix-loop-helix (bHLH) regulatory gene ‘BrTT8’ were highly up-regulated in purple lines after low temperature induction, and two negative regulatory genes ‘BrMYBL2.1’ and ‘BrLBD38.2’ were up-regulated in the white line. BrMYB2 and BrTT8 may play important roles in co-activating the anthocyanin structural genes in purple head Chinese cabbage after low-temperature induction, whereas down-regulation of BrMYB2 and up-regulation of some negative regulators might be responsible for white head phenotype formation. Data presented here provide new understanding into the anthocyanin biosynthesis mechanism during low temperature exposure in Brassica crops.


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