Polypeptides belonging to each of the three major chlorophyll a + b protein complexes are present in a chlorophyll-b-less barley mutant

Abstract

Polypeptides of the three major chlorophyll a+ b protein complexes were detected in a chlorophyll-b-less barley mutant (chlorina f2) using immunological techniques. Antibodies to CP I a, a photosystem I complex containing both the reaction center (CP I) and the chlorophyll a + b antenna (LHCI), detected substantial amounts of LHCI polypeptides in mutant thylakoids. Some polypeptides of the two photosystem-11-associated chlorophyll a + b complexes, CP 29 and LHCII, were also detected using antibodies raised against these complexes. The CP 29 apoprotein and the minor 25-kDa polypeptide of LHCII were present in amounts that could be seen by Coomassie blue staining. In contrast, the two major polypeptides of LHCII were greatly diminished in amount, and one of them may be completely absent. These data suggest that the absence of chlorophyll b may have differing effects on the synthesis, processing or turnover of the various chlorophyll a + b binding polypeptides.

Chlorophyll a/b-Binding Proteins, Pigment Conversions, and Early Light-Induced Proteins in a Chlorophyll b-less Barley Mutant

“…Our results differ in some aspects from those reported before Green, 1987, 1988;Morrissey et al, 1989;Harrison and Melis, 1992;Harrison et al, 1993). In cklorina f2 grown under normal light, White and Green (1987) reported the presence of the so-called 25-kD LHC I1 polypeptide (Lhcb3) and CP 29, which correspond to either Lhcb4 or Lhcb5 or both. Harrison and Melis (1992) and Harrison et al (1993) detected a single PSII LHC polypeptide, probably equivalent to Lhcb3, in cklorina f2.…”

“…Typically, these plants lack the major LHC proteins, Lhcbl and Lhcb2 (Simpson et al, 1985;White and Green, 1987;Allen et al, 1988) but still contain various amounts of minor LHC proteins (White and Green, 1988;Peter and Thornber, 1991;Marquardt and Bassi, 1993;Jahns and Krause, 1994). The barley (Hordeum vulgare L.) chlorina f2 mutant (Simpson et al, 1985) is the most wellcharacterized Chl b-deficient mutant.…”

The Senescence-Induced Staygreen Protein Regulates Chlorophyll Degradation

“…These results suggest that sgr has the same senescence defects as reported previously for other nonfunctional type C stay-green mutants. Thus, we conclude that leaf stay-greenness of sgr is mainly associated with a failure in the disassembling mechanism of the intact LHCP complexes in the thylakoid membranes, which is a prerequisite process for the degradation of Chls and Chl-free LHCPs during senescence (White and Green, 1987;Matile et al, 1999;Thomas and Howarth, 2000;Hö rtensteiner and Feller, 2002;Thomas et al, 2002).…”

“…In the chloroplasts, the LHCP complexes become stabilized via the integration of Chls, resulting in the inhibition of LHCP degradation, and the thylakoid membranes are not disassembled until after the degradation of both Chls and LHCPs (White and Green, 1987;Hö rtensteiner and Feller, 2002;Hö rtensteiner and Matile, 2004). In other words, the dissociation of Chls from the LHCP complexes is a prerequisite for the degradation of Chls, LHCPs, and thylakoid membranes in senescing leaf cells.…”

Assembly of the Light-Harvesting Complexes (LHCs) of Photosystem II (Monomeric LHC IIb Complexes Are Intermediates in the Formation of Oligomeric LHC IIb Complexes)

“…Vol. 106, 1994al., 1987Peter and Thomber, 1991a;Morishige and Thomber, 1992). The LHC IIc (CP26) complex has two apoproteins of 29 and 26.5 kD (Bassi et al, 1987;Peter and Thomber, 1991a;Falbel and Staehelin, 1992).…”