Reference - Detail
| RRC ID | 58209 |
|---|---|
| Author | Nakayasu M, Akiyama R, Kobayashi M, Lee HJ, Kawasaki T, Watanabe B, Urakawa S, Kato J, Sugimoto Y, Iijima Y, Saito K, Muranaka T, Umemoto N, Mizutani M. |
| Title | Identification of α-Tomatine 23-Hydroxylase Involved in the Detoxification of a Bitter Glycoalkaloid. |
| Journal | Plant Cell Physiol |
| Abstract |
Tomato plants (Solanum lycopersicum) contain steroidal glycoalkaloid α-tomatine, which functions as a chemical barrier to pathogens and predators. α-Tomatine accumulates in all tissues and at particularly high levels in leaves and immature green fruits. The compound is toxic and causes a bitter taste, but its presence decreases through metabolic conversion to nontoxic esculeoside A during fruit ripening. This study identifies the gene encoding a 23-hydroxylase of α-tomatine, which is a key to this process. Some 2-oxoglutarate-dependent dioxygenases were selected as candidates for the metabolic enzyme, and Solyc02g062460, designated Sl23DOX, was found to encode α-tomatine 23-hydroxylase. Biochemical analysis of the recombinant Sl23DOX protein demonstrated that it catalyzes the 23-hydroxylation of α-tomatine and the product spontaneously isomerizes to neorickiioside B, which is an intermediate in α-tomatine metabolism that appears during ripening. Leaves of transgenic tomato plants overexpressing Sl23DOX accumulated not only neorickiioside B but also another intermediate, lycoperoside C (23-O-acetylated neorickiioside B). Furthermore, the ripe fruits of Sl23DOX-silenced transgenic tomato plants contained lower levels of esculeoside A but substantially accumulated α-tomatine. Thus, Sl23DOX functions as α-tomatine 23-hydroxylase during the metabolic processing of toxic α-tomatine in tomato fruit ripening and is a key enzyme in the domestication of cultivated tomatoes. |
| Volume | 61(1) |
| Pages | 21-28 |
| Published | 2020-1-1 |
| DOI | 10.1093/pcp/pcz224 |
| PII | 5670534 |
| PMID | 31816045 |
| MeSH | Fruit / metabolism Gene Expression Regulation, Plant Inactivation, Metabolic Mixed Function Oxygenases / genetics Mixed Function Oxygenases / metabolism* Plant Leaves / metabolism Plants, Genetically Modified / metabolism Recombinant Proteins Solanum lycopersicum / enzymology* Solanum lycopersicum / genetics Solanum lycopersicum / metabolism* Taste* Tomatine / analogs & derivatives* Tomatine / metabolism* |
| IF | 4.062 |
| Times Cited | 0 |
| Altmetric score |
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| The most frequently cited source | X(Twitter) |
| Total number of mentions | 4 |
| Altmetric score changes over past 6months | 0.0 |
| Resource | |
| Tomato | TOMJPF00001(Micro-Tom) LEFL2019P01 LEFL2027P04 LEFL2046F14 |