RRC ID |
65585
|
Author |
Akiyama R, Nakayasu M, Umemoto N, Kato J, Kobayashi M, Lee HJ, Sugimoto Y, Iijima Y, Saito K, Muranaka T, Mizutani M.
|
Title |
Tomato E8 Encodes a C-27 Hydroxylase in Metabolic Detoxification of α-Tomatine during Fruit Ripening.
|
Journal |
Plant Cell Physiol
|
Abstract |
Tomato (Solanum lycopersicum) contains α-tomatine, a steroidal glycoalkaloid (SGA) that contributes to its defense against pathogens and herbivores through its bitter taste and toxicity. It accumulates at high levels in all the plant tissues, especially in leaves and immature green fruits, whereas it decreases during fruit ripening through metabolic conversion to the nontoxic esculeoside A, which accumulates in the mature red fruit. This study aimed to identify the gene encoding a C-27 hydroxylase that is a key enzyme in the metabolic conversion of α-tomatine to esculeoside A. The E8 gene, encoding a 2-oxoglutalate-dependent dioxygenase, is well-known as an inducible gene in response to ethylene during fruit ripening. The recombinant E8 was found to catalyze the C-27 hydroxylation of lycoperoside C to produce prosapogenin A and is designated as Sl27DOX. The ripe fruit of E8/Sl27DOX-silenced transgenic tomato plants accumulated lycoperoside C and exhibited decreased esculeoside A levels compared with the wild-type plants. Furthermore, E8/Sl27DOX-deletion in tomato accessions resulted in higher lycoperoside C levels in ripe fruit than in wild-type plants. Thus, E8/Sl27DOX functions as a C-27 hydroxylase of lycoperoside C in the metabolic detoxification of α-tomatine during tomato fruit ripening, and the efficient detoxification by E8/27DOX may provide an advantage in the domestication of cultivated tomatoes.
|
Volume |
62(5)
|
Pages |
775-783
|
Published |
2021-10-1
|
DOI |
10.1093/pcp/pcab080
|
PII |
6294823
|
PMID |
34100555
|
MeSH |
Fruit / growth & development
Fruit / metabolism*
Mixed Function Oxygenases / genetics
Mixed Function Oxygenases / metabolism*
Phylogeny
Plant Proteins / genetics
Plant Proteins / metabolism*
Plants, Genetically Modified
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
Saponins / metabolism
Solanum lycopersicum / genetics
Solanum lycopersicum / growth & development
Solanum lycopersicum / metabolism*
Substrate Specificity
Tomatine / analogs & derivatives*
Tomatine / metabolism
|
IF |
4.062
|
Resource |
Tomato |
TOMJPF00001 (Micro-Tom) |