Convergent evolution of syringyl lignin biosynthesis via distinct pathways in the lycophyte Selaginella and flowering plants.
Plant Cell
; 22(4): 1033-45, 2010 Apr.
Article
em En
| MEDLINE
| ID: mdl-20371642
ABSTRACT
Phenotypic convergence in unrelated lineages arises when different organisms adapt similarly under comparable selective pressures. In an apparent example of this process, syringyl lignin, a fundamental building block of plant cell walls, occurs in two major plant lineages, lycophytes and angiosperms, which diverged from one another more than 400 million years ago. Here, we show that this convergence resulted from independent recruitment of lignin biosynthetic cytochrome P450-dependent monooxygenases that route cell wall monomers through related but distinct pathways in the two lineages. In contrast with angiosperms, in which syringyl lignin biosynthesis requires two phenylpropanoid meta-hydroxylases C3'H and F5H, the lycophyte Selaginella employs one phenylpropanoid dual meta-hydroxylase to bypass several steps of the canonical lignin biosynthetic pathway. Transgenic expression of the Selaginella hydroxylase in Arabidopsis thaliana dramatically reroutes its endogenous lignin biosynthetic pathway, yielding a novel lignin composition not previously identified in nature. Our findings demonstrate a unique case of convergent evolution via distinct biochemical strategies and suggest a new way to genetically reconstruct lignin biosynthesis in higher plants.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Evolução Molecular
/
Sistema Enzimático do Citocromo P-450
/
Selaginellaceae
/
Lignina
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article