Quantum efficiency and antenna size of Photosystems IIα, IIβ and I in tobacco chloroplasts

Thielen, A.P.G.M.; Gorkom, Hans J. van

doi:10.1016/0005-2728(81)90012-8

Cited by 106 publications

(35 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent physiological measurements have been interpreted to indicate the presence of two functionally, and perhaps structurally distinct PSII complexes, referred to as PSII-a and PSII-,B (10,18,28). Our data place limitations on the applicability of this concept.…”

Section: Resultsmentioning

confidence: 85%

Non-Mendelian Inheritance of 3-(3,4-Dichlorophenyl)-1,1-dimethylurea-Resistant Thylakoid Membrane Properties in Chlamydomonas

Galloway

Mets²

1982

Plant Physiol.

View full text Add to dashboard Cite

A uniparentally inherited 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)-resistant mutant of Chiamydomonas reinhardii, Dr2, which has a resistance mechanism of the type defined as 'primary,' has been isolated. In vitro Hill reactions catalyzed by isolated thylakoid membranes reveal a reduced apparent affinity of the thylakoids for DCMU. These changes in membrane properties quantitatively account for the resistance of mutant Dr2 to herbicide inhibition of growth. There are several chemically distinct classes of herbicides which inhibit photosynthesis by blocking electron transport away from the reduced PSII acceptor, Q (20). DCMU, or diuron, is a potent member of the urea class, and atrazine is a potent and widely used triazine. In addition to having nearly identical physiological effects, these various herbicides show competitive binding to the same site on the thylakoid membrane (29). All of the herbicides share the common structural feature of a sp2 hybrid orbital carbon bonded to a nitrogen atom (9). At the same time, studies of substituent effects on the binding of different chemical classes show that one class may have important contacts with the binding site which are in a different spatial domain from some of the contacts which are important to a different class. Thus, it seems that each chemical class of these herbicides shares a portion of its binding site with all of the others, but that a portion is specific for that class (2).The derivative of atrazine which retains competitive binding to this site becomes covalently bonded to a 32,000 D thylakoid membrane polypeptide when the complex is UV irradiated (6). The reaction of this protein is dependent upon specific binding at the site, since it cannot be labeled in thylakoids from an atrazine-resistant biotype of Amaranthus which do not bind atrazine (23). Thus, this 32,000 D polypeptide is either part of or close to the binding site, but it is not known whether this part is shared with other herbicides or whether it interacts uniquely with triazines. Mattoo et al. (16) have shown that a 32,000 D polypeptide of Spirodela thylakoids, which is ordinarily quite sensitive to trypsin treatment of the membranes, is rendered resistant to digestion upon DCMU binding. If this protein is homologous with the azido-atrazine labeled protein, then it is apparent that it has important interactions with both triazines and ureas. Oettmeier et al. (21) found that an azido derivative of dinoseb (a dinitrophenol) acted as a photoaffinity label for a spinach thylakoid membrane polypeptide in the 40,000 D range. If this protein is not homologous to the atrazine-labeled protein, then one must conclude that the binding sites for the different classes of herbicides reach into the region of at least two proteins. It will be of interest to determine if herbicide resistance can arise from mutations in more than one thylakoid protein gene.We have initiated a study of resistance to DCMU in Chlamydomonas reinhardii with two main objectives (a) By using genetic variants, we hop...

show abstract

Section: Resultsmentioning

confidence: 85%

Non-Mendelian Inheritance of 3-(3,4-Dichlorophenyl)-1,1-dimethylurea-Resistant Thylakoid Membrane Properties in Chlamydomonas

Galloway

Mets²

1982

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…60%) represents the "tightly bound" or "nonmobile" fraction, that is in part connected to the CP26 complex (LHCIIb) while the remaining is still associated to the Chl a binding PSII core complex in the absence of both CP26 and CP29 (LHCIIa). In a complementary approach, the supramolecular organization of the PSII antenna system has been studied by determining PSII antenna size and LHCII subunit composition in mature and developing plants as well as in antenna mutants (Thielen and van Gorkom, 1981;Ghirardi et al, 1986;Glick and Melis, 1989;Morrissey et al, 1989). According to these studies, 35 Chl a are associated to the five polypeptides of the core complex, the only one which is assembled in plants grown under intermittent light.…”

Section: Organization Of the Psii Antenna Systemmentioning

confidence: 99%

“…A slightly modified version of the tripartite model, recognized as inadequate for the interpretation of lifetime data (Berens et al, 1985a, b), has recently been applied to interpret the heterogeneity of fluorescence lifetimes as observed by picosecond spectroscopy at both low and ambient temperatures in thylakoids and PSII membranes (Hodges and Moya, 1986), but this interpretation has been criticized by other authors (Wendler and Holzwart, 1987) who based their interpretation of fluorescence data on the intrinsic heterogeneity between different PSII reaction centers (PSII-a and PSII-p), introduced to explain the kinetics of the fluorescence induction curve (Melis and Homann, 1975;Melis and Duysens, 1979;Thielen and van Gorkom, 1981).…”

mentioning

confidence: 99%

CHLOROPHYLL BINDING PROTEINS WITH ANTENNA FUNCTION IN HIGHER PLANTS and GREEN ALGAE

Bassi

Rigoni

Giacometti

1990

Photochem & Photobiology

158

View full text Add to dashboard Cite

“…A possible biochemical basis for the postulated heterogeneity relates to PSII, demonstrated to consist of two different kinds of unit in [ 14]. The/3-units in [14] probably have a smaller optical cross-section than the o~-units [15], as the/3-units have little or no LHCP attached, unlike the tx-units [16]. Thus, the /]-units would be smaller than the a-units and would have a correspondingly larger diffusion coefficient than the a-units.…”

Section: Resultsmentioning

confidence: 99%

Studies on the kinetics of cation‐associated fluorescence changes in chloroplast membranes

Jennings¹,

Gerola²,

Garlaschi³

et al. 1982

FEBS Letters

View full text Add to dashboard Cite

Quantum efficiency and antenna size of Photosystems IIα, IIβ and I in tobacco chloroplasts

Cited by 106 publications

References 21 publications

Non-Mendelian Inheritance of 3-(3,4-Dichlorophenyl)-1,1-dimethylurea-Resistant Thylakoid Membrane Properties in Chlamydomonas

Non-Mendelian Inheritance of 3-(3,4-Dichlorophenyl)-1,1-dimethylurea-Resistant Thylakoid Membrane Properties in Chlamydomonas

CHLOROPHYLL BINDING PROTEINS WITH ANTENNA FUNCTION IN HIGHER PLANTS and GREEN ALGAE

Studies on the kinetics of cation‐associated fluorescence changes in chloroplast membranes

Contact Info

Product

Resources

About