Variation and inheritance of the Xanthomonas raxX-raxSTAB gene cluster required for activation of XA21-mediated immunity.
Mol Plant Pathol
; 20(5): 656-672, 2019 05.
Article
em En
| MEDLINE
| ID: mdl-30773771
ABSTRACT
The rice XA21-mediated immune response is activated on recognition of the RaxX peptide produced by the bacterium Xanthomonas oryzae pv. oryzae (Xoo). The 60-residue RaxX precursor is post-translationally modified to form a sulfated tyrosine peptide that shares sequence and functional similarity with the plant sulfated tyrosine (PSY) peptide hormones. The 5-kb raxX-raxSTAB gene cluster of Xoo encodes RaxX, the RaxST tyrosylprotein sulfotransferase, and the RaxA and RaxB components of a predicted type I secretion system. To assess raxX-raxSTAB gene cluster evolution and to determine its phylogenetic distribution, we first identified rax gene homologues in other genomes. We detected the complete raxX-raxSTAB gene cluster only in Xanthomonas spp., in five distinct lineages in addition to X. oryzae. The phylogenetic distribution of the raxX-raxSTAB gene cluster is consistent with the occurrence of multiple lateral (horizontal) gene transfer events during Xanthomonas speciation. RaxX natural variants contain a restricted set of missense substitutions, as expected if selection acts to maintain peptide hormone-like function. Indeed, eight RaxX variants tested all failed to activate the XA21-mediated immune response, yet retained peptide hormone activity. Together, these observations support the hypothesis that the XA21 receptor evolved specifically to recognize Xoo RaxX.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
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Oryza
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Xanthomonas
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Família Multigênica
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Proteínas Serina-Treonina Quinases
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Padrões de Herança
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Imunidade Vegetal
Idioma:
En
Revista:
Mol Plant Pathol
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos