The Physcomitrella patens unique alpha-dioxygenase participates in both developmental processes and defense responses

• DOI: 10.1186/s12870-015-0439-z
• Publication Date: 2015-02-11T00:06:34Z
• Authors: Lucina Machado; Alexandra Castro; Mats Hamberg; Gerard Bannenberg; Carina Gaggero; Carmen Castresana; Inés Ponce de León
• Keywords: Physcomitrella patens

Plant α-dioxygenases catalyze the incorporation of molecular oxygen into polyunsaturated fatty acids leading to formation oxylipins. In flowering plants, two main groups α-DOXs have been described. While α-DOX1 isoforms are mainly involved in defense responses against microbial infection and herbivores, α-DOX2 mostly related development. To gain insight roles played by these enzymes during land plant evolution, we performed biochemical, genetic analyses examine function single copy moss Physcomitrella patens α-DOX (Ppα-DOX) development pathogens. Recombinant Ppα-DOX protein catalyzed conversion 2-hydroperoxy derivatives with a substrate preference for α-linolenic, linoleic palmitic acids. is expressed tips young protonemal filaments maximum expression levels mitotically active undifferentiated apical cells. leafy gametophores, auxin producing tissues, including rhizoid axillary hairs. transcript activity increased tissues infected Botrytis cinerea or treated Pectobacterium carotovorum elicitors. B. leaves, Ppα-DOX-GUS proteins accumulated cells surrounding cells, suggesting protective mechanism. Targeted disruption did not cause visible developmental alteration compromise response. However, overexpressing Ppα-DOX, incubating wild-type Ppα-DOX-derived oxylipins, principally aldehyde heptadecatrienal, resulted smaller colonies less due reduction caulonemal filament growth chloronemal cell size compared normal tissues. addition, overexpression treatments oxylipins reduced cellular damage caused elicitors P. carotovorum. Our study shows that unique primitive patens, although apparently crucial, participates both response pathogens, from plants could originated duplication successive functional diversification after divergence bryophytes.