Journal Article

Endogenous α-Ketol Linolenic Acid Levels in Short Day-Induced Cotyledons are Closely Related to Flower Induction in <i>Pharbitis nil</i>

Masayuki Suzuki, Shoko Yamaguchi, Toshii Iida, Ikue Hashimoto, Hiromi Teranishi, Masaya Mizoguchi, Fumihiko Yano, Yasushi Todoroki, Naoharu Watanabe and Mineyuki Yokoyama

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 44, issue 1, pages 35-43
Published in print January 2003 | ISSN: 0032-0781
Published online January 2003 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pcg007
Endogenous α-Ketol Linolenic Acid Levels in Short Day-Induced Cotyledons are Closely Related to Flower Induction in Pharbitis nil

More Like This

Show all results sharing these subjects:

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

GO

Show Summary Details

Preview

α-Ketol linolenic acid [KODA, 9,10-ketol-octadecadienoic acid, that is 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid] is a signal compound found in Lemna paucicostata after exposure to stress, such as drought, heat or osmotic stress. KODA reacts with catecholamines to generate products that strongly induce flowering, although KODA itself is inactive [Yokoyama et al. (2000) Plant Cell Physiol. 41: 110; Yamaguchi et al. (2001) Plant Cell Physiol. 42: 1201]. We examined the role of KODA in the flower-induction process of Pharbitis nil (violet). KODA was identified for the first time in seedlings of P. nil grown under a flower-inductive condition (16-h dark exposure), by means of LC-SIM and LC-MS/MS. In addition, the changes in endogenous KODA levels (evaluated after esterification of KODA with 9-anthryldiazomethane) during the flower-inductive phase in short day-induced cotyledons were closely related to flower induction. The KODA concentration sharply increased in seedlings during the last 2 h of a 16-h dark period, while the KODA level showed no significant elevation under continuous light. The increase of KODA level occurred in cotyledonal blades, but not in other parts (petiole, hypocotyls and shoot tip). When the 16-h dark period was interrupted with a 10-min light exposure at the 8th h, flower induction was blocked and KODA level also failed to increase. The degree of elevation of KODA concentration in response to 16-h dark exposure was the highest when the cotyledons had just unfolded, and gradually decreased in seedlings grown under continuous light for longer periods, reaching the basal level at the 3rd day after unfolding. Flower-inducing ability also decreased in a similar manner. These results suggest that KODA may be involved in flower induction in P. nil.

Keywords: Keywords: Flower induction — KODA — Linolenic acid — Pharbitis nil — Photoperiod.; Abbreviations: ADAM, 9-anthryldiazomethane; GC-MS, gas chromatography combined with mass spectroscopy; 9-HPOT, 9-hydroperoxy-10(E),12(Z),15(Z)-octadecatrienoic acid; 13-HPOT, 13-hydroperoxy-9(Z),11(E),15(Z)-octadecatrienoic acid; I.S., internal standard; KODA, 9,10-ketol-octadecadienoic acid, that is 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid; LC-MS, high-performance liquid chromatography combined with mass spectroscopy; LC-SIM, high-performance liquid chromatography combined with selected ion-monitoring; LC-MS/MS, high-performance liquid chromatograph combined with mass spectroscopy/mass spectroscopy; LOX, lipoxygenase; NE, (–)-norepinephrine; TFA, trifluoroacetic acid.

Journal Article.  5841 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.