Development and Application of CRISPR/Cas9 to Improve Anthocyanin Pigmentation in Plants: Opportunities and Perspectives.

Rambutan is a tropical tree and its fruit has several favorable characteristics. To understand how the color of the rambutan fruit peel develops, the transcriptome, flavonoid metabolome, and carotenoid metabolome data of two rambutan cultivars, ‘BY2’ and ‘BY7’, which show yellow and red peels at maturity, respectively, were comprehensively analyzed at three developmental stages. We identified 26 carotenoid components and 53 flavonoid components in these cultivars. Anthocyanins were the main component contributing to the red color of ‘BY7’ after reaching ripeness. The carotenoid content decreased sharply as the fruit matured. Hence, we speculated that flavonols were the main contributors to the yellow color of the ‘BY2’ peel. In total, 6805 differentially expressed genes were screened by transcriptome analysis; the majority of them were enriched in metabolic pathways and the biosynthesis of secondary metabolites. Weighted gene co-expression network analysis results revealed that in addition to MYB and bHLH, ERF, WRKY, MYB-related, and C3H were the main potential transcription factors regulating the color of the rambutan peel. In addition, we also identified 12 structural genes associated with flavonoid biosynthesis. The research findings shed light on the molecular mechanisms of color acquisition in rambutan fruit peels, laying the foundation for the quality control of rambutan and the cultivation of differently colored cultivars of rambutan.

Comparative Metabolomic and Transcriptomic Analysis Reveals That Variations in Flavonoids Determine the Colors of Different Rambutan Cultivars

Targeted mutations of the BnPAP2 leads to yellow seed coat in Brassica napus L.

The basic helix-loop-helix (bHLH) proteins compose one of the largest transcription factor (TF) families in plants, which play a vital role in regulating plant biological processes including growth and development, stress response, and secondary metabolite biosynthesis. Ipomoea aquatica is one of the most important nutrient-rich vegetables. Compared to the common green-stemmed I. aquatica, purple-stemmed I. aquatica has extremely high contents of anthocyanins. However, the information on bHLH genes in I. aquatica and their role in regulating anthocyanin accumulation is still unclear. In this study, we confirmed a total of 157 bHLH genes in the I. aquatica genome, which were classified into 23 subgroups according to their phylogenetic relationship with the bHLH of Arabidopsis thaliana (AtbHLH). Of these, 129 IabHLH genes were unevenly distributed across 15 chromosomes, while 28 IabHLH genes were spread on the scaffolds. Subcellular localization prediction revealed that most IabHLH proteins were localized in the nucleus, while some were in the chloroplast, extracellular space, and endomembrane system. Sequence analysis revealed conserved motif distribution and similar patterns of gene structure within IabHLH genes of the same subfamily. Analysis of gene duplication events indicated that DSD and WGD played a vital role in the IabHLH gene family expansion. Transcriptome analysis showed that the expression levels of 13 IabHLH genes were significantly different between the two varieties. Of these, the IabHLH027 had the highest expression fold change, and its expression level was dramatically higher in purple-stemmed I. aquatica than that in green-stemmed I. aquatica. All upregulated DEGs in purple-stemmed I. aquatica exhibited the same expression trends in both qRT-PCR and RNA-seq. Three downregulated genes including IabHLH142, IabHLH057, and IabHLH043 determined by RNA-seq had opposite expression trends of those detected by qRT-PCR. Analysis of the cis-acting elements in the promoter region of 13 differentially expressed genes indicated that light-responsive elements were the most, followed by phytohormone-responsive elements and stress-responsive elements, while plant growth and development-responsive elements were the least. Taken together, this work provides valuable clues for further exploring IabHLH function and facilitating the breeding of anthocyanin-rich functional varieties of I. aquatica.

/pdf/comprehensive-analysis-of-bhlh-transcription-factors-in-s6zhv8p8.pdf

Comprehensive Analysis of bHLH Transcription Factors in Ipomoea aquatica and Its Response to Anthocyanin Biosynthesis

The purple leaves of Brassica napus are abundant in anthocyanins, which are renowned for their role in conferring distinct colors, stress tolerance, and health benefits, however the genetic basis of this trait in B. napus remains largely unelucidated. Herein, the purple leaf B. napus (PL) exhibited purple pigments in the upper epidermis and a substantial increase in anthocyanin accumulation, particularly of cyanidin, compared to green leaf B. napus (GL). The genetic control of the purple leaf trait was attributed to a semi-dominant gene, pl, which was mapped to the end of chromosome A03. However, sequencing of the fragments amplified by the markers linked to pl indicated that they were all mapped to chromosome B05 from B. juncea. Within this B05 chromosomal segment, the BjMYB113 gene-specific marker showed perfect co-segregation with the purple leaf trait in the F2 population, suggesting that the BjMYB113 introgression from B. juncea was the candidate gene for the purple leaf trait in B. napus. To further verify the function of candidate gene, CRISPR/Cas9 was performed to knock out the BjMYB113 gene in PL. The three myb113 mutants exhibited evident green leaf phenotype, absence of purple pigments in the adaxial epidermis, and a significantly reduced accumulation of anthocyanin compared to PL. Additionally, the genes involved in positive regulatory (TT8), late anthocyanin biosynthesis (DFR, ANS, UFGT), as well as transport genes (TT19) were significantly suppressed in the myb113 mutants, further confirming that BjMYB113 was response for the anthocyanin accumulation in purple leaf B. napus. This study contributes to an advanced understanding of the regulation mechanism of anthocyanin accumulation in B. napus. Map-based cloning and CRISPR/Cas9-based editing verified that BjMYB113 from B. juncea conferred the anthocyanin accumulation in purple leaf B. napus.

The introgression of BjMYB113 from Brassica juncea leads to purple leaf trait in Brassica napus

Yellow seed trait is a desirable characteristic with potential for increasing seed quality and commercial value in rapeseed, and anthocyanin and proanthocyanidins (PAs) are major seed-coat pigments. Few transcription factors involved in the regulation of anthocyanin and PAs biosynthesis have been characterized in rapeseed. In this study, we identified a transcription factor gene BnbHLH92a (BnaA06T0441000ZS) in rapeseed. Overexpressing BnbHLH92a both in Arabidopsis and in rapeseed reduced levels of anthocyanin and PAs. Correspondingly, the expression profiles of anthocyanin and PA biosynthesis genes (TT3, BAN, TT8, TT18, and TTG1) were shown by quantitative real-time PCR to be inhibited in BnbHLH92a-overexpressing Arabidopsis seeds, indicating that BnbHLH92a represses the anthocyanin and PA biosynthesis pathway in Arabidopsis. BnbHLH92a physically interacts with the BnTTG1 protein and represses the biosynthesis of anthocyanins and PAs in rapeseed. BnbHLH92a also binds directly to the BnTT18 promoter and represses its expression. These results suggest that BnbHLH92a is a novel upstream regulator of flavonoid biosynthesis in B. napus. 

BnbHLH92a negatively regulates anthocyanin and proanthocyanidin biosynthesis in Brassica napus

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Hao Yu

Author Tools

Chat about Author

Papers

BnbHLH92a negatively regulates anthocyanin and proanthocyanidin biosynthesis in Brassica napus