Limits...
Transcriptomic analysis of differentially expressed genes in an orange-pericarp mutant and wild type in pummelo (Citrus grandis).

Guo F, Yu H, Xu Q, Deng X - BMC Plant Biol. (2015)

Bottom Line: The transcription factors and genes corresponding to effected metabolic pathways may involved in the carotenoid regulation was confirmed by the qRT-PCR analysis in the MT pericarp.This study has provided a global picture of the gene expression changes in a novel mutant with distinct color in the fruit pericarp of pummelo.Interpretation of differentially expressed genes (DEGs) revealed new insight into the molecular regulation of β-carotene accumulation in the MT pericarp.

View Article: PubMed Central - PubMed

ABSTRACT

Background: The external colour of fruit is a crucial quality feature, and the external coloration of most citrus fruits is due to the accumulation of carotenoids. The molecular regulation of carotenoid biosynthesis and accumulation in pericarp is limited due to the lack of mutant. In this work, an orange-pericarp mutant (MT) which showed altered pigmentation in the pericarp was used to identify genes potentially related to the regulation of carotenoid accumulation in the pericarp.

Results: High Performance Liquid Chromatography (HPLC) analysis revealed that the pericarp from MT fruits had a 10.5-fold increase of β-carotene content over that of the Wild Type (WT). Quantitative real-time PCR (qRT-PCR) analysis showed that the expression of all downstream carotenogenic genes was lower in MT than in WT, suggesting that down-regulation is critical for the β-carotene increase in the MT pericarp. RNA-seq analysis of the transcriptome revealed extensive changes in the MT gene expression level, with 168 genes down-regulated and 135 genes up-regulated. Gene ontology (GO) and KEGG pathway analyses indicated seven reliable metabolic pathways are altered in the mutant, including carbon metabolism, starch and sucrose metabolism and biosynthesis of amino acids. The transcription factors and genes corresponding to effected metabolic pathways may involved in the carotenoid regulation was confirmed by the qRT-PCR analysis in the MT pericarp.

Conclusions: This study has provided a global picture of the gene expression changes in a novel mutant with distinct color in the fruit pericarp of pummelo. Interpretation of differentially expressed genes (DEGs) revealed new insight into the molecular regulation of β-carotene accumulation in the MT pericarp.

Show MeSH
The phenotype and carotenoid content in the WT and MT. (A, B) Appearances of MT and WT fruits at maturation. (C, D) Carotenoid profiles and concentrations in the pericarps of WT and MT at fruit maturation. The bar represents 2 cm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4352283&req=5

Fig1: The phenotype and carotenoid content in the WT and MT. (A, B) Appearances of MT and WT fruits at maturation. (C, D) Carotenoid profiles and concentrations in the pericarps of WT and MT at fruit maturation. The bar represents 2 cm.

Mentions: The pummelo MT was originally found in an orchard in Zhangzhou (Fujian, China) in the 2010s as a spontaneous bud mutation from the commercial variety of ‘guanxi’ pummelo. An obvious phenotypic change of the MT is the orange colour of the pericarp, showing a sharp contrast with the slight yellow colour of the mature pericarp in the WT fruit (Figure 1A, B). The orange-pericarp mutant was propagated by grafting onto different rootstocks and retained the stable phenotype of the orange-colour pericarp under field conditions, and no reversion to the parental phenotype has been observed so far. Moreover, 73 pairs of Simple Sequence Repeat (SSR) markers were used to evaluate the genetic background of the mutant. All the SSR patterns were the same between MT and WT (Additional file 1), indicating that the two genotypes shared an identical genetic background.Figure 1


Transcriptomic analysis of differentially expressed genes in an orange-pericarp mutant and wild type in pummelo (Citrus grandis).

Guo F, Yu H, Xu Q, Deng X - BMC Plant Biol. (2015)

The phenotype and carotenoid content in the WT and MT. (A, B) Appearances of MT and WT fruits at maturation. (C, D) Carotenoid profiles and concentrations in the pericarps of WT and MT at fruit maturation. The bar represents 2 cm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4352283&req=5

Fig1: The phenotype and carotenoid content in the WT and MT. (A, B) Appearances of MT and WT fruits at maturation. (C, D) Carotenoid profiles and concentrations in the pericarps of WT and MT at fruit maturation. The bar represents 2 cm.
Mentions: The pummelo MT was originally found in an orchard in Zhangzhou (Fujian, China) in the 2010s as a spontaneous bud mutation from the commercial variety of ‘guanxi’ pummelo. An obvious phenotypic change of the MT is the orange colour of the pericarp, showing a sharp contrast with the slight yellow colour of the mature pericarp in the WT fruit (Figure 1A, B). The orange-pericarp mutant was propagated by grafting onto different rootstocks and retained the stable phenotype of the orange-colour pericarp under field conditions, and no reversion to the parental phenotype has been observed so far. Moreover, 73 pairs of Simple Sequence Repeat (SSR) markers were used to evaluate the genetic background of the mutant. All the SSR patterns were the same between MT and WT (Additional file 1), indicating that the two genotypes shared an identical genetic background.Figure 1

Bottom Line: The transcription factors and genes corresponding to effected metabolic pathways may involved in the carotenoid regulation was confirmed by the qRT-PCR analysis in the MT pericarp.This study has provided a global picture of the gene expression changes in a novel mutant with distinct color in the fruit pericarp of pummelo.Interpretation of differentially expressed genes (DEGs) revealed new insight into the molecular regulation of β-carotene accumulation in the MT pericarp.

View Article: PubMed Central - PubMed

ABSTRACT

Background: The external colour of fruit is a crucial quality feature, and the external coloration of most citrus fruits is due to the accumulation of carotenoids. The molecular regulation of carotenoid biosynthesis and accumulation in pericarp is limited due to the lack of mutant. In this work, an orange-pericarp mutant (MT) which showed altered pigmentation in the pericarp was used to identify genes potentially related to the regulation of carotenoid accumulation in the pericarp.

Results: High Performance Liquid Chromatography (HPLC) analysis revealed that the pericarp from MT fruits had a 10.5-fold increase of β-carotene content over that of the Wild Type (WT). Quantitative real-time PCR (qRT-PCR) analysis showed that the expression of all downstream carotenogenic genes was lower in MT than in WT, suggesting that down-regulation is critical for the β-carotene increase in the MT pericarp. RNA-seq analysis of the transcriptome revealed extensive changes in the MT gene expression level, with 168 genes down-regulated and 135 genes up-regulated. Gene ontology (GO) and KEGG pathway analyses indicated seven reliable metabolic pathways are altered in the mutant, including carbon metabolism, starch and sucrose metabolism and biosynthesis of amino acids. The transcription factors and genes corresponding to effected metabolic pathways may involved in the carotenoid regulation was confirmed by the qRT-PCR analysis in the MT pericarp.

Conclusions: This study has provided a global picture of the gene expression changes in a novel mutant with distinct color in the fruit pericarp of pummelo. Interpretation of differentially expressed genes (DEGs) revealed new insight into the molecular regulation of β-carotene accumulation in the MT pericarp.

Show MeSH