Journal Article

Responses to Desiccation Stress in Bryophytes and an Important Role of Dithiothreitol-Insensitive Non-Photochemical Quenching Against Photoinhibition in Dehydrated States

Hayase Nabe, Ryoko Funabiki, Yasuhiro Kashino, Hiroyuki Koike and Kazuhiko Satoh

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 48, issue 11, pages 1548-1557
Published in print November 2007 | ISSN: 0032-0781
Published online November 2007 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pcm124
Responses to Desiccation Stress in Bryophytes and an Important Role of Dithiothreitol-Insensitive Non-Photochemical Quenching Against Photoinhibition in Dehydrated States

More Like This

Show all results sharing these subjects:

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

GO

Show Summary Details

Preview

The effects of air drying and hypertonic treatments in the dark on seven bryophytes, which had grown under different water environments, were studied. All the desiccation-tolerant species tested lost most of their PSII photochemical activity when photosynthetic electron transport was inhibited by air drying, while, in all the sensitive species, the PSII photochemical activity remained at a high level even when photosynthesis was totally inhibited. The PSI reaction center remained active under drying conditions in both sensitive and tolerant species, but the activity became non-detectable in the light only in tolerant species due to deactivation of the cyclic electron flow around PSI and of the back reaction in PSI. Light-induced non-photochemical quenching (NPQ) was found to be induced not only by the xanthophyll cycle but also by a ΔpH-induced, dithiothreitol-insensitive mechanism in both the desiccation-tolerant and -intolerant bryophytes. Both mechanisms are thought to have an important role in protecting desiccation-tolerant species from photoinhibition under drying conditions. Fluorescence emission spectra at 77K showed that dehydration-induced quenching of PSII fluorescence was observed only in tolerant species and was due to neither state 1–state 2 transition nor detachment of light-harvesting chlorophyll protein complexes from PSII core complexes.The presence of dehydration-induced quenching of PSI fluorescence was also suggested.

Keywords: Bryophyte; Desiccation tolerance; Hypertonic treatment; Non-photochemical quenching; PSII; Xanthophyll cycle

Journal Article.  6341 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.