Effects of dimethazone (FMC 57020) on chloroplast development

Duke, Stephen O.; Paul, Rex N.

doi:10.1016/0048-3575(86)90026-x

Cited by 29 publications

(4 citation statements)

References 36 publications

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“…The specific activity of Chi synthetase was about twice as high in the PLB fraction as in the PT fraction when ChJide was supplied exogenously. Further, the Chlide formed by phototransformation of the endogenous Pchlide had to pass through a spectral shift to shorter wavelengths similar to the Shibata shift of intact leaves before it was esterified, which is in agreement with the time sequence of these events in intact leaves (Akoyunoglou and Michalopoulos 1971, Henningsen and Thome 1973, Duke and Kenyon 1985.…”

supporting

confidence: 71%

Chlorophyll synthetase activity is relocated from transforming prolamellar bodies to developing thylakoids during irradiation of dark-grown wheat

Lindsten¹,

Wiktorsson²,

Ryberg³

et al. 1993

Physiol Plant

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Ryberg, M. and Sundqvist, C, 1993. Chlorophyll synthetase activity is relocated from transforming prolamellar bodies to developing thylakoids during irradiation of dark-grown wheat, -Physiol. Plant, 88: 29-36.Analyses of the esterification of newly fonned chlorophyllide in irradiated darkgrown leaves of wheat (Triticum aestivum L. cv. Kosack) suggest a translocation of chlorophyll synthetase activity from transforming prolamellar bodies to developing thylakoids. We have fractionated plastid inner membranes from dark-grown leaves and from leaves irradiated for 5, 10, or 20 min and eompared the in vitro esterification of chlorophyllide in two fractions, corresponding (in density) to the prolamellar body and the prothylakoid fraction of dark-grown leaves. The relative amounts of chlorophyllide, and total protein, as well as the specific esterification activity, increased with irradiation time in the prothylakoid fraction. The esterification of ehlorophyllide seems to depend on a transformation of the prolamellar body structure. The results are discussed also in relation to other events initiated by irradiation, such as the Shibata-shift and the altered distribution of NADPH-protochlorophyllide oxidoreductase (EC 1.3.1,33),

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confidence: 71%

Chlorophyll synthetase activity is relocated from transforming prolamellar bodies to developing thylakoids during irradiation of dark-grown wheat

Lindsten¹,

Wiktorsson²,

Ryberg³

et al. 1993

Physiol Plant

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“…A single preplant incorporated application of clomazone (dimethazone, FMC-57020, Command) controls many grasses and some broadleaf weeds. This compound reduces or stops the accumulation of plastid pigments in susceptible species by inhibiting an enzyme of the terpenoid pathway resulting in white, yellow, or pale green plants (7). The exact enzymatic site of clomazone action is currently unknown.…”

mentioning

confidence: 99%

Uptake and Metabolism of Clomazone in Tolerant-Soybean and Susceptible-Cotton Photomixotrophic Cell Suspension Cultures

Norman¹,

Liebl²,

Widholm³

1990

Plant Physiol.

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The percentage of absorbed clomazone converted to more polar metabolite(s) was significantly greater by the SB-M cells relative to COT-M cells at 6 and 24 hours after treatment, however, only small differences existed between the cell lines by 48 hours after treatment. Nearly identical levels of parental clomazone was recovered from both cell lines for all treatments. A pooled metabolite fraction isolated from SB-M cells had no effect on the leaf pigment content of susceptible velvetleaf (Abutilon theophrasti Medic.) or soybean seedlings. Conversely, a pooled metabolite fraction from COT-M cells reduced the leaf Chi content of velvetleaf. Soybean tolerance to clomazone appears to be due to differential metabolism (bioactivation) and/or differences at the site of action.Clomazone [2-(2-chlorophenyl)methyl-4,4-dimethyl-3-isoxazolidinone] is a selective herbicide for use in soybean (24). A single preplant incorporated application of clomazone (dimethazone, FMC-57020, Command) controls many grasses and some broadleaf weeds. This compound reduces or stops the accumulation of plastid pigments in susceptible species by inhibiting an enzyme of the terpenoid pathway resulting in white, yellow, or pale green plants (7). The exact enzymatic site of clomazone action is currently unknown. Some of the suggested sites of action include: (a) isopentenyl pyrophosphate isomerase (5, 19); (b) prenyl transferases (5, 19); (c) enzymatic phytylation of chlorophyllide (5, 6); and (d) any enzyme of the terpenoid pathway after geranyl-geranylpyrophosphate production (1). The only report regarding the ' Supported in part by funds from the Illinois Agricultural Experimental Station and FMC Corporation. mechanism of clomazone selectivity suggested that the large differences in clomazone toxicity observed between tolerant bell pepper (Capsicum annuum L.) and susceptible tomato (Lycopersicon esculentum Mill.) seedlings could not be attributed solely to differential absorption, translocation, or metabolism (26).Many researchers have reported the initiation of photoautotrophic and photomixotrophic cell suspensions (10,12,13,27), and their potential use in herbicide mechanism of action and metabolism studies (3,17,20). Soybean and cotton photoautotrophic cell suspensions have been reported to behave as young expanding leaves with respect to pigment production, photosynthesis, and respiration (3, 17). The primary differences between the cell suspension and whole plant metabolism are a relatively low ribulose-1 ,5-bisphosphate carboxylase activity and a relatively high phosphoenolpyruvate carboxylase activity in the cell suspension cultures (1 1).Pigment production is inhibited in both cell cultures by the standard pigment synthesis inhibiting herbicide fluridone (data not shown). The enzymatic site of fluridone action is phytoene desaturase of the terpenoid pathway (2). The SB-M2 and COT-M cell response to fluridone suggests that pigment synthesis in these cells occurs via the terpenoid pathway of whole plants. Consequently, the SB-M and COT-...

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“…Clomazone is an herbicide commonly used in agriculture. Clomazone has a dramatic effect on chloroplast pigmentation and results in white or pale green plants, depending on the amount applied ( Duke and Kenyon 1986 ; Duke and Paul 1986 ). In vivo, clomazone is oxidized to 5-ketoclomazone ( Ferhatoglu et al 2005 ).…”

Section: Resultsmentioning

confidence: 99%

A pipeline for identification of causal mutations in barley identifies Xantha-j as the chlorophyll synthase gene

Stuart,

Zakhrabekova,

Jørgensen

et al. 2024

Plant Physiology

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Thousands of barley (Hordeum vulgare L.) mutants have been isolated over the last century, and many are stored in gene banks across various countries. In the present work, we developed a pipeline to efficiently identify causal mutations in barley. The pipeline is also efficient for mutations located in centromeric regions. Through bulked-segregant analyses using whole genome sequencing of pooled F2 seedlings, we mapped two mutations and identified a limited number of candidate genes. We applied the pipeline on F2-mapping populations made from xan-j.59 (unknown mutation) and xan-l.82 (previously known). The Xantha-j (xan-j) gene was identified as encoding chlorophyll synthase, which catalyzes the last step in the chlorophyll biosynthetic pathway: the addition of a phytol moiety to the propionate side chain of chlorophyllide. Key amino-acid residues in the active site, including the binding sites of the isoprenoid and chlorophyllide substrates, were analyzed in an AlphaFold2-generated structural model of the barley chlorophyll synthase. Three allelic mutants, xan-j.19, xan-j.59, and xan-j.64 were characterized. While xan-j.19 is a one-base pair deletion and xan-j.59 is a nonsense mutation, xan-j.64 causes an S212F substitution in chlorophyll synthase. Our analyses of xan-j.64 and treatment of growing barley with clomazone, an inhibitor of chloroplastic isoprenoid biosynthesis, suggest that binding of the isoprenoid substrate is a prerequisite for the stable maintenance of chlorophyll synthase in the plastid. We further suggest that chlorophyll synthase is a sensor for coordinating chlorophyll and isoprenoid biosynthesis.

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Effects of dimethazone (FMC 57020) on chloroplast development

Cited by 29 publications

References 36 publications

Chlorophyll synthetase activity is relocated from transforming prolamellar bodies to developing thylakoids during irradiation of dark-grown wheat

Chlorophyll synthetase activity is relocated from transforming prolamellar bodies to developing thylakoids during irradiation of dark-grown wheat

Uptake and Metabolism of Clomazone in Tolerant-Soybean and Susceptible-Cotton Photomixotrophic Cell Suspension Cultures

A pipeline for identification of causal mutations in barley identifies Xantha-j as the chlorophyll synthase gene

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