Molecular evolution of the wound-induced serine protease inhibitor wip1 in Zea and related genera.
Mol Biol Evol
; 18(11): 2092-101, 2001 Nov.
Article
em En
| MEDLINE
| ID: mdl-11606705
ABSTRACT
Plant defense mechanisms have been the subject of intensive investigation. However, little is known about their long-term evolutionary dynamics. We investigated the molecular diversity of a wound-induced serine protease inhibitor, wip1, in the genus Zea, as well as the divergence of wip1 among four genera, Zea, Tripsacum, Sorghum, and Oryza, in order to gain insight into the long-term evolution of plant defense. The specific objectives of this study were to determine (1) whether wip1 has a history of positive or balancing selection, as has been shown for genes involved in plant defense against pathogens, and (2) if the evolutionary histories of wip1 inhibitory loops, which come into closest contact with proteases, differ from the evolutionary history of other parts of this gene. The Zea polymorphism data are consistent with a neutral evolutionary history. In contrast, relative-rate tests suggest a nonneutral evolutionary history. This inconsistency may indicate that selection acting on wip1 is episodic or that wip1 evolves in response to selection favoring novel alleles. We also detected significant heterogeneity in the evolutionary rates of the two inhibitory loops of wip1-one inhibitory loop is highly conserved, whereas the second has diverged rapidly. Because these two inhibitory loops are predicted to have very similar biochemical functions, the significantly different evolutionary histories suggest that these loops have different ecological functions.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Inibidores de Serina Proteinase
/
Evolução Molecular
/
Zea mays
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Biol Evol
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos