Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2017 Dec 22;23(1):25.
doi: 10.3390/molecules23010025.

Comparative Transcriptome Analysis of Genes Involved in Anthocyanin Biosynthesis in Red and Green Walnut (Juglans regia L.)

Yongzhou Li  1   2   3 , Xiang Luo  4 , Cuiyun Wu  5 , Shangyin Cao  6 , Yifei Zhou  7 , Bo Jie  8   9   10 , Yalong Cao  11   12   13 , Haijun Meng  14   15 , Guoliang Wu  16   17   18
Affiliations
Comparative Study

Comparative Transcriptome Analysis of Genes Involved in Anthocyanin Biosynthesis in Red and Green Walnut (Juglans regia L.)

Yongzhou Li et al. Molecules. .

Abstract

Fruit color is an important economic trait. The color of red walnut cultivars is mainly attributed to anthocyanins. The aim of this study was to explore the differences in the molecular mechanism of leaf and peel color change between red and green walnut. A reference transcriptome of walnut was sequenced and annotated to identify genes related to fruit color at the ripening stage. More than 290 million high-quality reads were assembled into 39,411 genes using a combined assembly strategy. Using Illumina digital gene expression profiling, we identified 4568 differentially expressed genes (DEGs) between red and green walnut leaf and 3038 DEGs between red and green walnut peel at the ripening stage. We also identified some transcription factor families (MYB, bHLH, and WD40) involved in the control of anthocyanin biosynthesis. The trends in the expression levels of several genes encoding anthocyanin biosynthetic enzymes and transcription factors in the leaf and peel of red and green walnut were verified by quantitative real-time PCR. Together, our results identified the genes involved in anthocyanin accumulation in red walnut. These data provide a valuable resource for understanding the coloration of red walnut.

Keywords: anthocyanins; differentially expressed genes (DEGs); leaf and peel; quantitative real-time PCR (qRT-PCR); red walnut; transcriptome analysis.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Unigenes differentially expressed between two different cultivars at fruit ripening stage. Blue: up-regulated genes; orange: down-regulated genes.
Figure 2
Figure 2
GO classification of unigenes in Juglans regia L. leaf and peel. Results are summarized in three main GO categories: biological process, cellular component, and molecular function.
Figure 3
Figure 3
Statistics of KEGG pathway enrichment. Vertical axis shows pathways, horizontal axis shows enrichment factor. Size of dot represents number of DEGs in the pathway. Dot color corresponds to scope of Q-value.
Figure 4
Figure 4
Expression analysis of seven candidate differentially expressed genes related to anthocyanin biosynthesis in leaf of red and green walnut at the fruit ripening stage by qRT-PCR. Relative transcript levels were calculated by ddCt method with Actin as the standard. ** p < 0.01.
Figure 5
Figure 5
Expression analysis of eight candidate differentially expressed genes related to anthocyanin biosynthesis in the peel of red and green walnut at the fruit ripening stage by qRT-PCR. Relative transcript levels were calculated by the ddCt method with Actin as the standard. * p < 0.05, ** p < 0.01.
Figure 6
Figure 6
Anthocyanin biosynthetic pathway. Abbreviations: PAL, phenylalanine ammonia lyase; C4H, cinnamate-4-hydroxylase; 4CL, 4-coumaroyl-coA synthase; CHS, chalcone synthase; CHI, chalcone isomerase; F3′H, flavonoid-3′-hydroxylase; F3′5′H, flavonoid-3′5′-hydroxylase; F3H, flavanone-3-hydroxylase; DFR, dihydroflavonol 4-reductase; ANS, anthocyanidin synthase; UFGT, flavonoid-3-O-glucosyltransferase; GST, glutathione S-transferase; MATE, toxic compound extrusion; MRP, multidrug resistance-associated protein.
See this image and copyright information in PMC

References

    1. Aradhya M., Woeste K., Velasco D. Genetic diversity, structure and differentiation in cultivated walnut (Juglans regia L.) Acta Hortic. 2010;861:127–132. doi: 10.17660/ActaHortic.2010.861.16. - DOI
    1. Xi R.T., Zhang Y.P. Chinese Fruit Annals. Walnut. 1st ed. China Forestry Publishing House; Beijing, China: 1996. pp. 1–9.
    1. Mc Granahan G., Leslie C. ‘Robert Livermore’, a Persian walnut cultivar with a red seedcoat. Hortic. Sci. 2004;39:1772.
    1. Hanbali L.M.B., Ghadieh R.A., Hasan H.K., Nakhal Y.J., Haddad J. Measurement of antioxidant activity and antioxidant compounds under versatile extraction conditions: I. The immuno-biochemical antioxidant properties of sweet cherry (Prunus avium) extracts. Anti-Inflamm. Anti-Allergy Agents Med. Chem. 2013;12:173–187. doi: 10.2174/1871523011312020009. - DOI - PubMed
    1. Kelebek H., Selli S. Evaluation of chemical constituents and antioxidant activity of sweet cherry (Prunus avium L.) cultivars. Int. J. Food Sci. Technol. 2011;46:2530–2537. doi: 10.1111/j.1365-2621.2011.02777.x. - DOI

Publication types

MeSH terms