Articles
Following the track of a genetic variation that modifies the catechin/epicatechin ratio in Japanese plum fruits
Article number
1450_41
Pages
309 – 316
Language
English
Abstract
Japanese plum fruits contain phenolic compounds from the flavan-3-ol and proanthocyanidin (PA) family, including (+)-catechin and (-)-epicatechin.
Associated with the bitterness and astringency, (+)-catechin and (-)-epicatechin are biosynthesized by the LAR and ANR enzymes, respectively.
Additionally, genes encoding for these enzymes are transcriptionally regulated by transcription factors (TFs) belonging to the MYB, bHLH and WD40 families, which compose the MBW complex.
Previously, our group studied the phenolic composition of Japanese plum fruits of an F1 progeny from the cross between the cultivars ‘98-99’ and ‘Angeleno’, which showed a higher concentration of catechin and epicatechin, respectively.
We observed that individuals whose predominant flavan-3-ol was (+)-catechin or (-)-epicatechin segregated 1:1, so we could perform fine mapping using ~300 individuals from crosses with ‘Angeleno’ as a parent.
A<1 Mb interval containing six candidate genes possibly involved in flavonoid biosynthesis regulation was defined.
However, none of these candidates was expressed as indicated by RNA-seq experiments, including S1 and S4 fruit developmental stages.
In parallel, phylogenetic analysis using flavonoid-related MYBs of Arabidopsis allowed us to identify 11 PsMYBs putatively regulating the PA biosynthesis.
Expression analysis of immature and ripe fruit helped us to detect the gene Chr3.400, a member of the MYB gene family, which showed an expression 10-fold higher in ‘98-99’ than ‘Angeleno’ in S1. The closest homologous of this gene was PpMYB7, previously reported to regulate the expression of LAR but no ANR in peach.
According to these results, we identified a novel putative element in PA biosynthesis regulation involved in the flavan-3-ol profile in Japanese plum.
Associated with the bitterness and astringency, (+)-catechin and (-)-epicatechin are biosynthesized by the LAR and ANR enzymes, respectively.
Additionally, genes encoding for these enzymes are transcriptionally regulated by transcription factors (TFs) belonging to the MYB, bHLH and WD40 families, which compose the MBW complex.
Previously, our group studied the phenolic composition of Japanese plum fruits of an F1 progeny from the cross between the cultivars ‘98-99’ and ‘Angeleno’, which showed a higher concentration of catechin and epicatechin, respectively.
We observed that individuals whose predominant flavan-3-ol was (+)-catechin or (-)-epicatechin segregated 1:1, so we could perform fine mapping using ~300 individuals from crosses with ‘Angeleno’ as a parent.
A<1 Mb interval containing six candidate genes possibly involved in flavonoid biosynthesis regulation was defined.
However, none of these candidates was expressed as indicated by RNA-seq experiments, including S1 and S4 fruit developmental stages.
In parallel, phylogenetic analysis using flavonoid-related MYBs of Arabidopsis allowed us to identify 11 PsMYBs putatively regulating the PA biosynthesis.
Expression analysis of immature and ripe fruit helped us to detect the gene Chr3.400, a member of the MYB gene family, which showed an expression 10-fold higher in ‘98-99’ than ‘Angeleno’ in S1. The closest homologous of this gene was PpMYB7, previously reported to regulate the expression of LAR but no ANR in peach.
According to these results, we identified a novel putative element in PA biosynthesis regulation involved in the flavan-3-ol profile in Japanese plum.
Publication
Authors
I. Pacheco, B. Battistoni, J. Ibáñez, R. Infante, A. Allan, R. Espley
Keywords
candidate genes, flavan-3-ols, gene-expression, Japanese plum, stone fruits
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