Proanthocyanidins(PAs) are specialized metabolites that infuence persimmon fruit quality.Normal astringent(A)-type and non-astringent(NA)-type mutants show significant variation in PA accumulation, but the infuencing ...Proanthocyanidins(PAs) are specialized metabolites that infuence persimmon fruit quality.Normal astringent(A)-type and non-astringent(NA)-type mutants show significant variation in PA accumulation, but the infuencing mechanism remains unclear. In this study, among the six identified DTXs/MATEs proteins associated with PA accumulation, we observed that allelic variation and preferential transport by Dk DTX5/MATE5 induced variation in PA accumulation for A-type and NA-type fruit. The expression pattern of Dk DTX5/MATE5 was correlated with PA accumulation in NA-type fruit. Upregulation and downregulation of Dk DTX5/MATE5 promoted and inhibited PA accumulation, respectively, in the NA-type fruit. Interestingly, transporter assays of Xenopus laevis oocytes indicated that Dk DTX5/MATE5 preferentially transported the PA precursors catechin, epicatechin, and epicatechin gallate, resulting in their increased ratios relative to the total PAs, which was the main source of variation in PA accumulation between the A-type and NA-type. The allele lacking Ser-84 in Dk DTX5/MATE5 was identified as a dominantly expressed gene in the A-type and lost its transport function. Site-directed mutagenesis revealed that Dk DTX5/MATE5 binds to PA precursors via Ser-84. These findings clarify the association between the transporter function of Dk DTX5/MATE5 and PA variation, and can contribute to the breeding of new cultivars with improved fruit quality.展开更多
基金supported by the National Key R&D Program of China (2019YFD1000600)。
文摘Proanthocyanidins(PAs) are specialized metabolites that infuence persimmon fruit quality.Normal astringent(A)-type and non-astringent(NA)-type mutants show significant variation in PA accumulation, but the infuencing mechanism remains unclear. In this study, among the six identified DTXs/MATEs proteins associated with PA accumulation, we observed that allelic variation and preferential transport by Dk DTX5/MATE5 induced variation in PA accumulation for A-type and NA-type fruit. The expression pattern of Dk DTX5/MATE5 was correlated with PA accumulation in NA-type fruit. Upregulation and downregulation of Dk DTX5/MATE5 promoted and inhibited PA accumulation, respectively, in the NA-type fruit. Interestingly, transporter assays of Xenopus laevis oocytes indicated that Dk DTX5/MATE5 preferentially transported the PA precursors catechin, epicatechin, and epicatechin gallate, resulting in their increased ratios relative to the total PAs, which was the main source of variation in PA accumulation between the A-type and NA-type. The allele lacking Ser-84 in Dk DTX5/MATE5 was identified as a dominantly expressed gene in the A-type and lost its transport function. Site-directed mutagenesis revealed that Dk DTX5/MATE5 binds to PA precursors via Ser-84. These findings clarify the association between the transporter function of Dk DTX5/MATE5 and PA variation, and can contribute to the breeding of new cultivars with improved fruit quality.
