Physiology and plastid fine structure of deetiolating Lemna minor

1976 ◽  
Vol 54 (15) ◽  
pp. 1819-1826 ◽  
Author(s):  
Hugh Frick ◽  
Raymond F. Jones
Keyword(s):  
Higher Plants ◽  
Lemna Minor ◽  
Red Light ◽  
Acid Synthesis ◽  
Light Illumination ◽  
Fresh Weight ◽  
Plastid Development ◽  
Prolamellar Bodies ◽  
Rate Of Increase ◽  
Etiolated Plants

During the 12-h lag period in chlorophyll accumulation after the onset of white-light illumination of Lemna minor etiolated for 35 days, a rapid increase in visible fronds per culture occurred. This new frond production then assumed a log-linear rate of increase, and total protein per unit fresh weight came to parallel the rate of increase in fresh weight per plant. The ribosomal RNA content of 45-day-etiolated plants was deficient in 23S and 16S species compared with green plants. The prolamellar bodies of etioplasts were either tightly or loosely paracrystalline within the same cell; they were without extended perforate lamellae, which developed during far-red-light illumination even while prolamellar bodies persisted. The development of chloroplasts in deetiolating L. minor was typical of other higher plants. The developmental sequence in green Lemna included proplastid to deeply stacked granal chloroplast within several millimetres. Plastid profiles suggestive of division configurations occurred only in primordial cells of green and etiolated plants. The relatively small numbers of plastids in any given stage of differentiation may account for the sensitivity of plastid development to inhibitors of protein and nucleic acid synthesis.

Inhibition of δ-Aminolevulinic Acid Synthesis by Glyphosate

Weed Science ◽  
1981 ◽  
Vol 29 (5) ◽  
pp. 571-577 ◽  
Author(s):  
Lynn M. Kitchen ◽  
William W. Witt ◽  
Charles E. Rieck
Keyword(s):  
Carbon Dioxide ◽  
Zea Mays ◽  
Aminolevulinic Acid ◽  
Higher Plants ◽  
Acid Synthesis ◽  
The Other ◽  
Porphyrin Ring ◽  
Fresh Weight ◽  
Ring Compounds ◽  
Site Of Action

The effect of glyphosate [N-(phosphonomethyl) glycine] on barley (Hordeum vulgareL.) and corn (Zea maysL.) shoot δ-aminolevulinic acid (ALA) production was examined by monitoring ALA content in the tissue and measuring incorporation of14C precursors into ALA and chlorophylla. Barley shoot ALA content was significantly decreased by 1 mM glyphosate after 9, 11, and 15 h of illumination. ALA production by treated barley shoots was 30 nmoles•g fresh weight-1•h-1at each interval tested, compared with 75 to 120 nmoles•g fresh weight-1•h-1for the control. In corn shoots, ALA content was reduced 32, 45, and 58% by 0.1, 1.0, and 10.0 mM glyphosate, respectively, after 12 h illumination. Incorporation studies with14C-glutamate,14C-α-ketoglutarate, and14C-glycine into ALA showed a 77, 92, and 91% inhibition, respectively, in barley shoots treated with 1 mM glyphosate. Incorporation of14C-ALA into chlorophyllawas not affected by 1 mM glyphosate. Thus, the site of action of glyphosate may involve two enzyme pathways:one controlling the conversion of α-ketoglutarate to ALA, and the other controlling the condensation of glycine with succinyl CoA to form ALA and carbon dioxide. Inhibition of ALA synthesis blocks synthesis of chlorophyll, as well as all other porphyrin ring compounds found in higher plants. Thus, inhibition of ALA synthesis may be an integral component of the herbicidal mode of action of glyphosate.

Phytochrome control of the lag phase of chlorophyll accumulation in Lemna minor

1975 ◽  
Vol 53 (21) ◽  
pp. 2405-2410 ◽  
Author(s):  
Hugh Frick
Keyword(s):  
Lemna Minor ◽  
Red Light ◽  
Lag Phase ◽  
Chlorophyll Accumulation ◽  
Rapid Accumulation ◽  
Lag Period ◽  
Accumulation Phase ◽  
And Control ◽  
Etiolated Plants ◽  
Rate Of Accumulation

The 10- to 12-h lag phase in chlorophyll accumulation preceding the rapid accumulation phase in Lemna minor de-etiolating in the light was eliminated by a red light preillumination given about the length of the lag period before the onset of continuous red light. Neither the rate after the lag nor the extent of cholorophyll accumulation differed between preilluminated and control plants. Both the rate of accumulation in controls and the absolute stimulation by preillumination were shown to depend upon the length of time the etiolated plants had been grown in darkness up to 93 days. Only one photoproduct of preillumination contributed to the elimination of the chlorophyll lag phase, but the effect of red light was only partially (about 60%) nullified by subsequent far-red light.

Plastid and seedling development in SAN-9789 [4-chloro-5-(methylamine)-2-(α,α,α-trifluoro-m-tolyl)-3-(2H)-pyridasinone]-treated etiolated bean seedlings

1980 ◽  
Vol 58 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Anthony D. Pardo ◽  
Jerome A. Schiff
Keyword(s):  
Normal Development ◽  
Higher Plants ◽  
Red Light ◽  
Thylakoid Membranes ◽  
Phaseolus Vulgaris L ◽  
Trifoliate Leaf ◽  
Prolamellar Bodies ◽  
Developmental Effects ◽  
Carotenoid Synthesis ◽  
Membrane Components

SAN 9789[4-chloro-5-(methylamine)-2-(α,α,α-trifluoro-m-tolyl)-3-(2H)-pyridasinone] inhibits carotenoid synthesis at the level of phytoene in Phaseolus vulgaris L. Although carotenoids are greatly reduced in the primary leaves, prolamellar bodies and thylakoid membranes are formed containing phototransformable protochlorophyll(ide). SAN 9789 also produces developmental effects similar to those of red light since seedlings treated in darkness are short, show plumular unhooking, formation of adventitious roots, expansion of primary leaves and full expansion of the first trifoliate leaf and first internode. The effect is not directly on phytochrome since far red light does not reverse the effect of SAN. If abscisic acid (ABA) is indeed formed from carotenoids, we may be observing the consequences of reduced levels of ABA leading to reduced ethylene production as occurs with red light. The first trifoliate leaf of SAN-treated plants contains practically no carotenoids (0.2%) compared with untreated 7-day-old, etiolated primary leaves yet shows normal development of etioplasts, prolamellar bodies, thylakoid membranes, and phototransformable protochlorophyll(ide). In Euglena, lack of carotenoids stops synthesis and assembly of other membrane components; in higher plants this type of regulation does not appear to operate.

scholarly journals Artificial complementary chromatic acclimation gene expression system in Escherichia coli

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Dwi Ariyanti ◽  
Kazunori Ikebukuro ◽  
Koji Sode
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Light Exposure ◽  
Expression System ◽  
Red Light ◽  
Green Light ◽  
Light Illumination ◽  
Multiple Gene ◽  
Gene Expression System ◽  
Chromatic Acclimation

Abstract Background The development of multiple gene expression systems, especially those based on the physical signals, such as multiple color light irradiations, is challenging. Complementary chromatic acclimation (CCA), a photoreversible process that facilitates the control of cellular expression using light of different wavelengths in cyanobacteria, is one example. In this study, an artificial CCA systems, inspired by type III CCA light-regulated gene expression, was designed by employing a single photosensor system, the CcaS/CcaR green light gene expression system derived from Synechocystis sp. PCC6803, combined with G-box (the regulator recognized by activated CcaR), the cognate cpcG2 promoter, and the constitutively transcribed promoter, the PtrcΔLacO promoter. Results One G-box was inserted upstream of the cpcG2 promoter and a reporter gene, the rfp gene (green light-induced gene expression), and the other G-box was inserted between the PtrcΔLacO promoter and a reporter gene, the bfp gene (red light-induced gene expression). The Escherichia coli transformants with plasmid-encoded genes were evaluated at the transcriptional and translational levels under red or green light illumination. Under green light illumination, the transcription and translation of the rfp gene were observed, whereas the expression of the bfp gene was repressed. Under red light illumination, the transcription and translation of the bfp gene were observed, whereas the expression of the rfp gene was repressed. During the red and green light exposure cycles at every 6 h, BFP expression increased under red light exposure while RFP expression was repressed, and RFP expression increased under green light exposure while BFP expression was repressed. Conclusion An artificial CCA system was developed to realize a multiple gene expression system, which was regulated by two colors, red and green lights, using a single photosensor system, the CcaS/CcaR system derived from Synechocystis sp. PCC6803, in E. coli. The artificial CCA system functioned repeatedly during red and green light exposure cycles. These results demonstrate the potential application of this CCA gene expression system for the production of multiple metabolites in a variety of microorganisms, such as cyanobacteria.

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

Far-Red Light Blocks Greening of Arabidopsis Seedlings via a Phytochrome A: Mediated Change in Plastid Development

1996 ◽  
Vol 8 (4) ◽  
pp. 601 ◽  
Author(s):  
Simon A. Barnes ◽  
Naoko K. Nishizawa ◽  
Ronaldo B. Quaggio ◽  
Garry C. Whitelam ◽  
Nam-Hai Chua
Keyword(s):  
Red Light ◽  
Phytochrome A ◽  
Plastid Development

scholarly journals N-1-naphthylphthalamic acid stimulates tomato hypocotyl elongation, elevates ethylene levels and alters metabolic homeostasis

2018 ◽  
Author(s):  
Sapana Nongmaithem ◽  
Sameera Devulapalli ◽  
Yellamaraju Sreelakshmi ◽  
Rameshwar Sharma
Keyword(s):  
Butyric Acid ◽  
Metabolic Networks ◽  
Higher Plants ◽  
Red Light ◽  
Hypocotyl Elongation ◽  
Stimulated Emission ◽  
Ethylene Action ◽  
Naphthylphthalamic Acid ◽  
Exogenous Ethylene ◽  
Species Specific

One sentence summaryN-1-naphthylphthalamic acid (NPA) treatment stimulates tomato hypocotyl elongation likely by elevating ethylene emission and lowering indole-3-butyric acid levels in the seedlings.AbstractIn higher plants, phytohormone indole-3-acetic acid is characteristically transported from the apex towards the base of the plant, termed as polar auxin transport (PAT). Among the inhibitors blocking PAT, N-1-naphthylphthalamic acid (NPA) that targets ABCB transporters is most commonly used. NPA-treated light-grown Arabidopsis seedlings show severe inhibition of hypocotyl and root elongation. In light-grown tomato seedlings, NPA inhibited root growth, but contrary to Arabidopsis stimulated hypocotyl elongation. The NPA-stimulation of hypocotyl elongation was milder in blue, red, and far-red light-grown seedlings. The NPA-treatment stimulated emission of ethylene from the seedlings. The scrubbing of ethylene by mercuric perchlorate reduced NPA-stimulated hypocotyl elongation. NPA action on hypocotyl elongation was antagonized by 1-methylcyclopropene, an inhibitor of ethylene action. NPA-treated seedlings had reduced levels of indole-3-butyric acid and higher levels of zeatin in the shoots. NPA did not alter indole-3-acetic levels in shoots. The analysis of metabolic networks indicated that NPA-treatment induced moderate shifts in the networks compared to exogenous ethylene that induced a drastic shift in metabolic networks. Our results indicate that in addition to ethylene, NPA-stimulated hypocotyl elongation in tomato may also involve zeatin and indole-3-butyric acid. Our results indicate that NPA-mediated physiological responses may vary in a species-specific fashion.

Untersuchungen zur Lokalisation von Flavonoiden in Plastiden, I / Experiments on the Localisation of Flavonoids in Plastids, I

1972 ◽  
Vol 27 (10) ◽  
pp. 1216-1224 ◽  
Author(s):  
Gottfried Weissenböck ◽  
Ingrid Fleing ◽  
Hans Georg Ruppel
Keyword(s):  
Avena Sativa ◽  
Flavonoid Compounds ◽  
Prolamellar Bodies ◽  
Etiolated Plants

Etioplasts aqueously isolated from leaves of etiolated plants of two varieties of Avena sativa contain all the flavonoid compounds of the whole leaf: apigenin-7-methoxy (?)-8-C-rhamnosylglucosylgly (u) coside (or -8-C-glucosylrhamnosylgly (u) coside), apigenin-6-C-arabinosylglucoside, apigenin-8-C-glucosylglucoside and in variety 1 a derivative of kaempferol, in variety 2 the flavone-C-glycoside saponaretin. The distribution of these compounds however is different in etioplasts and leaves: in etioplasts of variety 1 the kaempferol-derivative, in those of variety 2 saponaretin is relatively enriched. Presence of flavonoids could also be demonstrated in isolated prolamellar bodies from etioplasts of Avena variety 2.

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