Overexpression of SbMyb60 impacts phenylpropanoid biosynthesis and alters secondary cell wall composition in Sorghum bicolor.
Plant J
; 85(3): 378-95, 2016 Feb.
Article
em En
| MEDLINE
| ID: mdl-26712107
ABSTRACT
The phenylpropanoid biosynthetic pathway that generates lignin subunits represents a significant target for altering the abundance and composition of lignin. The global regulators of phenylpropanoid metabolism may include MYB transcription factors, whose expression levels have been correlated with changes in secondary cell wall composition and the levels of several other aromatic compounds, including anthocyanins and flavonoids. While transcription factors correlated with downregulation of the phenylpropanoid biosynthesis pathway have been identified in several grass species, few transcription factors linked to activation of this pathway have been identified in C4 grasses, some of which are being developed as dedicated bioenergy feedstocks. In this study we investigated the role of SbMyb60 in lignin biosynthesis in sorghum (Sorghum bicolor), which is a drought-tolerant, high-yielding biomass crop. Ectopic expression of this transcription factor in sorghum was associated with higher expression levels of genes involved in monolignol biosynthesis, and led to higher abundances of syringyl lignin, significant compositional changes to the lignin polymer and increased lignin concentration in biomass. Moreover, transgenic plants constitutively overexpressing SbMyb60 also displayed ectopic lignification in leaf midribs and elevated concentrations of soluble phenolic compounds in biomass. Results indicate that overexpression of SbMyb60 is associated with activation of monolignol biosynthesis in sorghum. SbMyb60 represents a target for modification of plant cell wall composition, with the potential to improve biomass for renewable uses.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
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Parede Celular
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Regulação da Expressão Gênica de Plantas
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Propanóis
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Sorghum
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Lignina
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Plant J
Assunto da revista:
BIOLOGIA MOLECULAR
/
BOTANICA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos