A SlMYB75-centred transcriptional cascade regulates trichome formation and sesquiterpene accumulation in tomato.
J Exp Bot
; 72(10): 3806-3820, 2021 05 04.
Article
em En
| MEDLINE
| ID: mdl-33619530
ABSTRACT
Tomato trichomes act as a mechanical and chemical barrier against pests. An R2R3 MYB transcription factor gene, SlMYB75, is highly expressed in type II, V, and VI trichomes. SlMYB75 protein is located in the nucleus and possesses transcriptional activation activity. Down-regulation of SlMYB75 increased the formation of type II, V, and VI trichomes, accumulation of δ-elemene, ß-caryophyllene, and α-humulene in glandular trichomes, and tolerance to spider mites in tomato. In contrast, overexpression of SlMYB75 inhibited trichome formation and sesquiterpene accumulation, and increased plant sensitivity to spider mites. RNA-Seq analyses of the SlMYB75 RNAi line indicated massive perturbation of the transcriptome, with a significant impact on several classes of transcription factors. Expression of the MYB genes SlMYB52 and SlTHM1 was strongly reduced in the RNAi line and increased in the SlMYB75-overexpressing line. SlMYB75 protein interacted with SlMYB52 and SlTHM1 and activated their expression. SlMYB75 directly targeted the promoter of the cyclin gene SlCycB2, increasing its activity. The auxin response factor SlARF4 directly targeted the promoter of SlMYB75 and inhibited its expression. SlMYB75 also bound to the promoters of the terpene synthase genes SlTPS12, SlTPS31, and SlTPS35, inhibiting their transcription. Our findings indicate that SlMYB75 perturbation affects several transcriptional circuits, resulting in altered trichome density and metabolic content.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
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Sesquiterpenos
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Fatores de Transcrição
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Solanum lycopersicum
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Tricomas
Limite:
Animals
Idioma:
En
Revista:
J Exp Bot
Assunto da revista:
BOTANICA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
China