RRC ID 33340
著者 Machado L, Castro A, Hamberg M, Bannenberg G, Gaggero C, Castresana C, de León IP.
タイトル The Physcomitrella patens unique alpha-dioxygenase participates in both developmental processes and defense responses.
ジャーナル BMC Plant Biol
Abstract BACKGROUND:Plant α-dioxygenases catalyze the incorporation of molecular oxygen into polyunsaturated fatty acids leading to the formation of oxylipins. In flowering plants, two main groups of α-DOXs have been described. While the α-DOX1 isoforms are mainly involved in defense responses against microbial infection and herbivores, the α-DOX2 isoforms are mostly related to development. To gain insight into the roles played by these enzymes during land plant evolution, we performed biochemical, genetic and molecular analyses to examine the function of the single copy moss Physcomitrella patens α-DOX (Ppα-DOX) in development and defense against pathogens.
RESULTS:Recombinant Ppα-DOX protein catalyzed the conversion of fatty acids into 2-hydroperoxy derivatives with a substrate preference for α-linolenic, linoleic and palmitic acids. Ppα-DOX is expressed during development in tips of young protonemal filaments with maximum expression levels in mitotically active undifferentiated apical cells. In leafy gametophores, Ppα-DOX is expressed in auxin producing tissues, including rhizoid and axillary hairs. Ppα-DOX transcript levels and Ppα-DOX activity increased in moss tissues infected with Botrytis cinerea or treated with Pectobacterium carotovorum elicitors. In B. cinerea infected leaves, Ppα-DOX-GUS proteins accumulated in cells surrounding infected cells, suggesting a protective mechanism. Targeted disruption of Ppα-DOX did not cause a visible developmental alteration and did not compromise the defense response. However, overexpressing Ppα-DOX, or incubating wild-type tissues with Ppα-DOX-derived oxylipins, principally the aldehyde heptadecatrienal, resulted in smaller moss colonies with less protonemal tissues, due to a reduction of caulonemal filament growth and a reduction of chloronemal cell size compared with normal tissues. In addition, Ppα-DOX overexpression and treatments with Ppα-DOX-derived oxylipins reduced cellular damage caused by elicitors of P. carotovorum.
CONCLUSIONS:Our study shows that the unique α-DOX of the primitive land plant P. patens, although apparently not crucial, participates both in development and in the defense response against pathogens, suggesting that α-DOXs from flowering plants could have originated by duplication and successive functional diversification after the divergence from bryophytes.
巻・号 15
ページ 45
公開日 2015-2-12
DOI 10.1186/s12870-015-0439-z
PII s12870-015-0439-z
PMID 25848849
PMC PMC4334559
MeSH Botrytis / physiology Bryopsida / enzymology* Bryopsida / genetics* Bryopsida / growth & development Bryopsida / immunology Dioxygenases / genetics* Dioxygenases / metabolism* Gene Expression Regulation, Plant* Molecular Sequence Data Pectobacterium carotovorum / physiology Phylogeny Plant Immunity* Plant Proteins / genetics Plant Proteins / metabolism Polymerase Chain Reaction Sequence Analysis, DNA
IF 3.497
引用数 12
WOS 分野 PLANT SCIENCES
リソース情報
シロイヌナズナ / 植物培養細胞・遺伝子 pdp