Location: Vegetable Crops ResearchTitle: Transcriptome Analysis Reveals the Fruit Color Variation in Ailanthus Altissima
|MA, YAPING - Nanjing Forestry University
|FENG, XUERUI - Ningxia University
|LI, YUNMAO - Ningxia University
|SONG, LIHUA - Ningxia University
|GAO, HANDONG - Nanjing Forestry University
|CAO, BING - Ningxia University
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2023
Publication Date: 1/23/2023
Citation: Ma, Y., Mura, J.D., Feng, X., Li, Y., Song, L., Gao, H., Cao, B. 2023. Transcriptome analysis uncovers the fruit color regulatory mechanisms in Ailanthus altissima. Industrial Crops and Products. 2023 Jan;175(1):e13867. https://doi.org/10.1111/ppl.13867.
Interpretive Summary: Ailanthus altissima is a deciduous tree native to China that is found all over the world. The color of the fruit is the most notable feature of this tree. Identifying the genes and regulatory processes involved in its fruit color can help improve its favorable characteristics. The red fruit of Ailanthus altissima accumulates more anthocyanin than the white fruit. We discovered 21 co-expressed modules by comparing red and white fruit genes, two of which were associated with flavonoids and anthocyanins. We found two genes involved in anthocyanin biosynthesis, AaDFR and AaANS, and their overexpression increased anthocyanin and flavonoid levels in fruits. This research will aid in comprehending anthocyanin and flavonoid biosynthetic pathways, which will assist in enhancing these two components in other fruit crops that contain anthocyanins and flavonoids.
Technical Abstract: Ailanthus altissima is a deciduous tree endemic to China and is distributed worldwide. It is used as an ornamental as it has excellent biotic and abiotic stress resistance and high commercial value. The color of the fruit is an economically important aspect of these plants. This study aimed to analyze the transcriptomes of the white and red fruit of A. altissima and screen and validate the key genes regulating flavonoid and anthocyanin biosynthesis. Samples of A. altissima fruit were collected 30, 45, and 60 days after flowering, and their pigment and sugar content were determined. The relative anthocyanin content was significantly higher in the red than white fruit. The fruit samples were also used in transcriptome analysis, and 73,807 unigenes were assembled and annotated to seven databases. Twenty-one co-expressed modules were identified by weighted gene co-expression network analysis, and two of them were associated with flavonoids and anthocyanins. Furthermore, 126, 30, and 124 differentially expressed genes were screened between the white and red fruit at three growth stages. The genes regulating flavonoid, amino acid, and sugar metabolism were identified. AaDFR (A. altissima bifunctional dihydroflavonol 4- reductase/flavanone 4-reductase) and AaANS (A. altissima anthocyanidin synthase) were associated with flavonoid and anthocyanin metabolism. AaDFR and AaANS family members were also identified, and their basic physicochemical characteristics, conserved domains, motif compositions, phylogenetics, and expression levels were analyzed. AaDFR and AaANS overexpression in transgenic Arabidopsis significantly increased seed and foliar flavonoid and anthocyanin content. The present study elucidated the regulatory mechanisms of fruit color development and laid the foundation for breeding A. altissima plants with economically acceptable traits.