Localization of NADPH‐protochlorophyllide oxidoreductase in dark‐grown wheat (Triticum aestivum) by immuno‐electron microscopy before and after transformation of the prolamellar bodies

Abstract

The localization of NADPH‐protochlorophyllide oxidoreductase (PChlide reductase, EC 1.6.99.–) in dark‐grown and in irradiated dark‐grown leaves of wheat (Triticum aestivum L. cv. Walde) was investigated by subjecting thin sections of Lowicryl K4M‐embedded leaf pieces to a monospecific antiserum raised against PChlide reductase followed by protein A‐gold. A well‐preserved antigenicity of the tissue was achieved by polymerizing the resin under UV‐light at low temperature. In dark‐grown leaves PChlide reductase was found in prolamellar bodies only. In leaves irradiated for 30 min with white light PChlide reductase was found not only in the transformed prolamellar bodies but also to a large extent in connection with the prothylakoids. The localization of PChlide reductase is discussed in relation to fluorescence emission spectra of the dark‐grown and greening leaves. We conclude that the light‐dependent transformation of protochlorophyllide to chlorophyllide initiates a translocation of PChlide reductase from the prolamellar bodies to the prothylakoids.

The Shibata Shift and the Transformation of Etioplasts to Chloroplasts in Wheat with Clomazone (FMC 57020) and Amiprophos-Methyl (Tokunol M)

“…Fixation of the tissue in 1% glutaraldehyde and embedding in the resin Lowicryl K4M was performed according to the method of Ryberg and Dehesh (21) except that the times for dehydration, infiltration, and polymerization were prolonged. During the tissue dehydration and infiltration with resin, the temperature was gradually lowered from 5°C to about -35°C over a 5-h period by using a Hetofrig cooling bath (Heto, Birkerod, Denmark) modified for this purpose.…”

“…By approximately 3 h, the thylakoids are no longer perforated, and grana stacks begin to form. On a time scale similar to that of the Shibata shift, much of the PCR is relocated from the PLBs to the PTs (21). By 9-h irradiation, PCR is barely detectable in wheat leaves by Western blotting or immunogold labeling of thin sections (M Ryberg, unpublished data; cf.…”

Correlated Changes in the Activity, Amount of Protein, and Abundance of Transcript of NADPH:Protochlorophyllide Oxidoreductase and Chlorophyll Accumulation during Greening of Cucumber Cotyledons

“…The enzyme has a molecular mass of 36 to 37 kD (Apel et al, 1980;Beer and Griffiths, 1981;Roper et al, 1983;Forreiter et al, 1990) and is one of the major proteins localized in the prolamellar body of etioplasts (Griffiths, 1978;Dehesh et al, 1986;Ryberg and Dehesh, 1986). Small amounts of the enzyme have also been reported to be localized in thylakoid membranes (Forreiter and Apel, 1993;Teakle and Griffiths, 1993) or envelopes (Joyard et al, 1990;Pineau et al, 1993) of mature chloroplasts.…”

Margareta Ryberg (1946–2012): a personal tribute

“…Margareta spent a few research periods abroad. In Kiel, Germany, she worked with Klaus Apel (now at the Boyce Thompson Institute in Ithaca, NY, USA) and with Katayoon (Katie) Dehesh (now at University of California at Davis, CA, USA; see Dehesh and Ryberg 1985;Ryberg and Dehesh 1986;Dehesh et al 1986). Katie came to be like a sister to Margareta.…”

“…Eventually her studies became concerned with structural aspects and the nature of prolamellar bodies. Polyacrylamide electrophoresis, electron microscopy, liquid chromatography, mass spectroscopy, and immunolabeling were added to the methods in order to study the nature and role of the protein components and the localization and roles of light-dependent NADPH:protochlorophyllide oxidoreductases, PORs Sundqvist 1982, 1988;Ryberg and Dehesh 1986). While POR concentration decreased in plastids during illumination, it remained constant in the cytoplasm ).…”