Journal Article

Expression of Allene Oxide Cyclase and Accumulation of Jasmonates during Organogenic Nodule Formation from Hop (<i>Humulus lupulus</i> var. Nugget) Internodes

Ana M. Fortes, Otto Miersch, Peter R. Lange, Rui Malhó, Pilar S. Testillano, Maria del Carmen Risueño, Claus Wasternack and Maria S. Pais

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 46, issue 10, pages 1713-1723
Published in print October 2005 | ISSN: 0032-0781
Published online October 2005 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pci187
Expression of Allene Oxide Cyclase and Accumulation of Jasmonates during Organogenic Nodule Formation from Hop (Humulus lupulus var. Nugget) Internodes

More Like This

Show all results sharing these subjects:

  • Biochemistry
  • Molecular and Cell Biology
  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

A crucial step in the biosynthesis of jasmonic acid (JA) is the formation of its stereoisomeric precursor, cis-(+)-12-oxophytodienoic acid (OPDA), which is catalyzed by allene oxide cyclase (AOC, EC 5.3.99.6). A cDNA of AOC was isolated from Humulus lupulus var. Nugget. The ORF of 765 bp encodes a 255 amino acid protein, which carries a putative chloroplast targeting sequence. The recombinant protein without its putative chloroplast target sequence showed significant AOC activity. Previously we demonstrated that wounding induces organogenic nodule formation in hop. Here we show that the AOC transcript level increases in response to wounding of internodes, peaking between 2 and 4 h after wounding. In addition, Western blot analysis showed elevated levels of AOC peaking 24 h after internode inoculation. The AOC increase was accompanied by increased JA levels 24 h after wounding, whereas OPDA had already reached its highest level after 12 h. AOC is mostly present in the vascular bundles of inoculated internodes. During prenodule and nodule formation, AOC levels were still high. JA and OPDA levels decreased down to 10 and 118 pmol (g FW)–1, respectively, during nodule formation, but increased during plantlet regeneration. Double immunolocalization analysis of AOC and Rubisco in connection with lugol staining showed that AOC is present in amyloplasts of prenodular cells and in the chloroplasts of vacuolated nodular cells, whereas meristematic cells accumulated little AOC. These data suggest a role of AOC and jasmonates in organogenic nodule formation and plantlet regeneration from these nodules.

Keywords: Allene oxide cyclase; Humulus lupulus; Jasmonates; Organogenic nodule; AOC, allene oxide cyclase; AOS, allene oxide synthase; JA, jasmonic acid; LOX, lipoxygenase; OPDA, 12-oxophytodienoic acid; OPR, OPDA reductase; ON, organogenic nodule

Journal Article.  7281 words.  Illustrated.

Subjects: Biochemistry ; Molecular and Cell Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.