Journal Article

The Distribution of Protochlorophyllide and Chlorophyll within Seedlings of the <i>lip</i>1 Mutant of Pea

Mehdi Seyedi, Michael P. Timko and Christer Sundqvist

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 42, issue 9, pages 931-941
Published in print September 2001 | ISSN: 0032-0781
Published online September 2001 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pce118
The Distribution of Protochlorophyllide and Chlorophyll within Seedlings of the lip1 Mutant of Pea

More Like This

Show all results sharing these subjects:

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

GO

Show Summary Details

Preview

The distribution of protochlorophyllide (Pchlide) and NADPH-Pchlide oxidoreductase (POR) was characterized in the epicotyls and roots of wild-type pea (Pisum sativum L. cv. Alaska) and lip1, a mutant with light-independent photomorphogenesis caused by a mutation in the COP1 locus. The upper part of the dark-grown lip1 mutant epicotyls had a high Pchlide content that decreased downward the organ. The elevated Pchlide level in lip1 seedlings was a result of the differentiation of more proplastids into Pchlide-containing plastids. The cortex cells in the lip1 epicotyl were filled with such plastids in contrast to the cortex cells of wild-type seedlings. The mutant also developed Pchlide-containing plastids in the roots, indicating the suppressing effect of the COP1 locus on development of plastids in the corresponding tissues in dark-grown wild-type plants. The distribution of Pchlide-containing plastids in dark-grown lip1 mutant stem and root was similar to the distribution of chloroplasts in irradiated wild-type plants. Both wild-type and lip1 epicotyls contained mostly short wavelength Pchlide fluorescing at 631 nm with only a small shoulder at 654 nm, which was transformed to a minute amount of chlorophyllide (Chlide) by flash irradiation. In contrast, with continuous irradiation a considerable amount of Chlide was formed especially in the lip1 epicotyls. Immunoblots indicated the presence of POR, as a 36 kDa band, in epicotyls of both dark-grown wild-type and lip1 mutant seedlings. However, lip1 stem tissue had a higher content of POR than the wild-type pea. The high content of POR was unexpected as lip1 lacked both the 654 nm fluorescing Pchlide form and the regular PLBs. In light, a significant amount of chlorophyll was formed also in the roots of the lip1 seedlings.

Keywords: Key words: Chlorophyll — Epicotyl — Fluorescence spectrum — lip1 — Pea (Pisum sativum L.) — Protochlorophyllide.; Abbreviations: Chlide, chlorophyllide; Pchlide, protochlorophyllide; PLB, prolamellar body; POR, NADPH-protochlorophyllide oxidoreductase.

Journal Article.  6757 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.