Benzyladenine as a regulator of chlorophyll synthesis in cucumber cotyledons

1971 ◽  
Vol 49 (12) ◽  
pp. 2197-2201 ◽  
Author(s):  
R. A. Fletcher ◽  
Dianne McCullagh
Keyword(s):  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Chlorophyll Synthesis ◽  
Lag Phase ◽  
Rna And Protein Synthesis ◽  
Chlorophyll Production ◽  
Cucumber Cotyledons ◽  
Ala Synthetase ◽  
Rate Limiting ◽  
Chlorophyll Formation

Pretreatment of etiolated cucumber cotyledons (4–10 days old) with benzyladenine (BA) increased the amount of chlorophyll produced in light. BA also eliminated the lag phase in chlorophyll formation, which in the water controls lasted for [Formula: see text]. Addition of δ-aminolevulinic acid (ALA) to the etiolated cotyledons resulted in the production of protochlorophyllide (PCHLD) in the dark. The BA-pretreated cotyledons did not make any PCHLD in the dark. The inhibitors of RNA and protein synthesis, actinomycin D, chloramphenicol, and cycloheximide (CH), inhibited BA's effect on chlorophyll production, with CH being the most effective. We propose that BA's effect on increased chlorophyll formation is mediated by inducing production of proteins including ALA synthetase, the rate-limiting enzyme in chlorophyll biosynthesis.

Stimulation of chlorophyll synthesis in cucumber cotyledons by benzyladenine

1973 ◽  
Vol 51 (5) ◽  
pp. 937-939 ◽  
Author(s):  
R. A. Fletcher ◽  
C. Teo ◽  
A. Ali
Keyword(s):  
Total Synthesis ◽  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Chlorophyll Synthesis ◽  
Lag Phase ◽  
Cucumber Cotyledons ◽  
Ala Synthetase ◽  
Rate Limiting ◽  
Chlorophyll Formation ◽  
Stimulation Of

When exposed to light, etiolated cucumber cotyledons exhibited a lag phase in chlorophyll biosynthesis. Pretreatment of the cotyledons with benzyladenine (BA) eliminated the lag phase and stimulated chlorophyll formation. In BA-treated cotyledons, the incorporation of 14C-leucine into protein and the total synthesis of protein were higher than in the non-BA-treated controls. After BA treatment and exposure to light, the accumulation of δ-aminolevulinic acid in the cotyledons increased with time and was higher than in the controls, where a lag phase was apparent. These results support our hypothesis that BA affects chlorophyll formation by inducing the production of proteins including ALA-synthetase, the rate-limiting enzyme in chlorophyll biosynthesis.

Induction of delta-aminolevulinic acid synthetase in muscle by exercise or thyroxine

1979 ◽  
Vol 236 (3) ◽  
pp. R180-R183 ◽  
Author(s):  
J. O. Holloszy ◽  
W. W. Winder
Keyword(s):  
Thyroid Hormones ◽  
Aminolevulinic Acid ◽  
Treadmill Running ◽  
Synthetase Activity ◽  
Mitochondrial Enzymes ◽  
Vigorous Exercise ◽  
Ala Synthetase ◽  
Rate Limiting ◽  
Rate Controlling Step ◽  
Mitochondrial Cytochromes

There is evidence that delta-aminolevulinic acid (ALA) synthetase is the rate-limiting enzyme in heme biosynthesis. Accumulation of the apoproteins of the mitochondrial cytochromes appears to be regulated by availability of heme. Exercise and thyrotoxicosis bring about increases in the cytochromes, and in other mitochondrial enzymes, in muscle. In this context, we have examined the effects of exercise and of thyroid hormones on ALA synthetase activity in skeletal muscle. Treadmill running and injection of thyroid hormones both resulted in significant increases in muscle ALA synthetase activity. A rise in ALA synthetase activity was evident within 17 h after a bout of vigorous exercise and 14 h after a single injection of thyroid hormones. The increase in ALA synthetase preceded the increase in cytochrome c, which was used as a mitochondrial marker. These results are compatible with the hypothesis that a relationship exists between heme synthesis and mitochondrial growth in which the rate-controlling step is ALA synthetase activity.

scholarly journals No effect of plant growth retarding compounds and growth stimulators on indolo-3-acetic acid oxidase activity in greening cucumber cotyledons

2015 ◽  
Vol 42 (3) ◽  
pp. 441-452 ◽  
Author(s):  
J. S. Knypl
Keyword(s):  
Oxidase Activity ◽  
Chlorophyll Synthesis ◽  
Lag Phase ◽  
Acid Oxidase ◽  
Iaa Oxidase ◽  
Crude Enzyme Extract ◽  
Chlorophyll Accumulation ◽  
Cucumber Cotyledons ◽  
Amo 1618 ◽  
Molecular Sieving

Cotyledons dissected from 5-day-old etiolated cucumber seedlings were incubated in solutions on AMO-1618, B-Nine, CCC and Phosfon D for 48 h in light. In some tests the retardants were applied in mixed solutions with GA<sub>3</sub> or BAP. IAA oxidase was extracted and purified by means of molecular sieving through a bed of Sephadex G-25. The retardants inhibited chlorophyll synthesis by 50 % or more, and had essentially no effect on IAA oxidase activity per cotyledon basis. GA<sub>3</sub> and BAP also had no effect on enzyme activity in spite of a fact that the compounds stimulated growth of the cotyledons. The crude enzyme extract from B-Nine treated cotyledons showed lower IAA oxidase activity in comparison with the water treated control, the effect being due to a longer lag-phase preceding the initiation of IAA oxidation. KNO<sub>3</sub> strikingly stimulated expansional growth of the cotyledons, the effect being correlated with the accelerated chlorophyll accumulation. KNO<sub>3</sub> had no effect on IAA oxidase activity per cotyledon and decreased it per gram fr wt. It is concluded that [1] the growth rate of cucumber cotyledons is not correlated with IAA oxidase activity, and ;[2] the growth retarding compounds do not affect IAA oxidase system is this tissue.

scholarly journals Porphyrin Synthesis by Cultured Lymphocytes

Blood ◽  
1972 ◽  
Vol 39 (4) ◽  
pp. 568-574 ◽  
Author(s):  
Alan S. Josephson ◽  
Richard D. Levere ◽  
Ivan Lowenthal ◽  
Fred Swerdlow ◽  
Mark Ginsberg
Keyword(s):  
Culture Medium ◽  
Aminolevulinic Acid ◽  
Sex Steroid ◽  
Heme Synthesis ◽  
Peripheral Lymphocytes ◽  
Porphyrin Synthesis ◽  
Ala Synthetase ◽  
Rate Limiting ◽  
Steroid Metabolite ◽  
Cells Cultured

Abstract Peripheral lymphocytes were cultured in the presence and absence of phytohemagglutinin (PHA). Porphyrin synthesis was visually estimated by fluorescence and quantitated by fluorometry. No visual fluorescence was noted in cells cultured with or without PHA. Addition of δ-aminolevulinic acid (ALA) to cultures of either transformed or nontransformed lymphocytes resulted in fluorescence, indicating porphyrin synthesis. Certain sex steroid metabolites stimulate porphyrin synthesis by induction of the rate-limiting enzyme ALA synthetase. Erythropoietin also increases the rate of heme synthesis. Phytohemagglutinin-transformed and nontransformed cells were cultured with the addition of either 11-keto pregnanolone or erythropoietin, and neither agent induced porphyrin synthesis. Only when ALA was added to the culture medium was the measured fluorescence statistically greater than in control cultures. These studies indicate that the enzymes of porphyrin synthesis distal to ALA synthetase, the rate-limiting enzyme, are present in all cultured lymphocytes. The rate-limiting enzyme is not induced by PHA transformation, even in the presence of a 5-β-H steroid metabolite or erythropoietin.

scholarly journals Effect of Low Temperature on Chlorophyll Biosynthesis and Chloroplast Biogenesis of Rice Seedlings during Greening

2020 ◽  
Vol 21 (4) ◽  
pp. 1390 ◽  
Author(s):  
Yuqing Zhao ◽  
Qiaohong Han ◽  
Chunbang Ding ◽  
Yan Huang ◽  
Jinqiu Liao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Aminolevulinic Acid ◽  
Oryza Sativa L ◽  
Chlorophyll Biosynthesis ◽  
Chilling Stress ◽  
Chlorophyll Synthesis ◽  
Rice Seedling ◽  
Rice Seedlings ◽  
Plastid Development

Rice (Oryza sativa L.) frequently suffers in late spring from severe damage due to cold spells, which causes the block of chlorophyll biosynthesis during early rice seedling greening. However, the inhibitory mechanism by which this occurs is still unclear. To explore the responsive mechanism of rice seedlings to low temperatures during greening, the effects of chilling stress on chlorophyll biosynthesis and plastid development were studied in rice seedlings. Chlorophyll biosynthesis was obviously inhibited and chlorophyll accumulation declined under low temperatures during greening. The decrease in chlorophyll synthesis was due to the inhibited synthesis of δ-aminolevulinic acid (ALA) and the suppression of conversion from protochlorophyllide (Pchlide) into chlorophylls (Chls). Meanwhile, the activities of glutamate-1-semialdehyde transaminase (GSA-AT), Mg-chelatase, and protochlorophyllide oxidoreductase (POR) were downregulated under low temperatures. Further investigations showed that chloroplasts at 18 °C had loose granum lamellae, while the thylakoid and lamellar structures of grana could hardly develop at 12 °C after 48 h of greening. Additionally, photosystem II (PSII) and photosystem I (PSI) proteins obviously declined in the stressed seedlings, to the point that the PSII and PSI proteins could hardly be detected after 48 h of greening at 12 °C. Furthermore, the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) and cell death were all induced by low temperature. Chilling stress had no effect on the development of epidermis cells, but the stomata were smaller under chilling stress than those at 28 °C. Taken together, our study promotes more comprehensive understanding in that chilling could inhibit chlorophyll biosynthesis and cause oxidative damages during greening.

scholarly journals 5-Aminolevulinic acid fermentation using engineered Saccharomyces cerevisiae

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Kiyotaka Y. Hara ◽  
Masaru Saito ◽  
Hiroko Kato ◽  
Kana Morikawa ◽  
Hiroshi Kikukawa ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metabolic Engineering ◽  
Aminolevulinic Acid ◽  
Value Added ◽  
Acid Fermentation ◽  
Rate Limiting Step ◽  
Ala Synthetase ◽  
Engineered Saccharomyces Cerevisiae ◽  
Rate Limiting ◽  
Ala Biosynthesis

Abstract Background 5′-Aminolevulinic acid (ALA) is widely used in the pharmaceutical industry, healthcare, and food production, and is a substrate for the biosynthesis of heme, which is required for respiration and photosynthesis. Enhancement of ALA biosynthesis has never been developed in Saccharomyces cerevisiae, which is a well-known model microorganism used for bioproduction of many value-added compounds. Results We demonstrated that metabolic engineering significantly improved ALA production in S. cerevisiae. First, we found that overexpression of HEM1, which encodes ALA synthetase, increased ALA production. Furthermore, addition of an optimal amount of glycine, a substrate for ALA biosynthesis, or levulinic acid, an inhibitor of ALA dehydrogenase, effectively increased ALA production. Next, we developed an assay for multiple metabolites including ALA and found that aconitase, encoded by ACO1 and ACO2, is the rate-limiting enzyme of ALA biosynthesis when sufficient glycine is supplied. Overexpression of ACO2 further enhanced ALA production in S. cerevisiae overexpressing HEM1. Conclusions In this study, ALA production in S. cerevisiae was enhanced by metabolic engineering. This study also shows a strategy to identify the rate-limiting step of a target synthetic pathway by assay for multiple metabolites alongside the target product. This strategy can be applied to improve production of other valuable products in the well-studied and well-industrialized microorganism S. cerevisiae.

scholarly journals The Abolition of the Lag Phase in Greening Cucumber Cotyledons by Exogenous δ-Aminolevulinic Acid

1974 ◽  
Vol 53 (4) ◽  
pp. 615-618 ◽  
Author(s):  
Paul A. Castelfranco ◽  
Petrovia M. Rich ◽  
Samuel I. Beale
Keyword(s):  
Aminolevulinic Acid ◽  
Lag Phase ◽  
Cucumber Cotyledons

scholarly journals Effect of chlorophyll biosynthesis-related genes on the leaf color in Hosta (Hosta plantaginea Aschers) and tobacco (Nicotiana tabacum L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingying Zhang ◽  
Changhai Sui ◽  
Huimin Liu ◽  
Jinjiao Chen ◽  
Zhilin Han ◽  
...  
Keyword(s):  
Light Intensity ◽  
Antioxidant Capacity ◽  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Expression Level ◽  
Virus Induced Gene Silencing ◽  
Leaf Color ◽  
Color Changes ◽  
Light Intensities ◽  
Structure Changes

Abstract Background ‘Regal Splendour’ (Hosta variety) is famous for its multi-color leaves, which are useful resources for exploring chloroplast development and color changes. The expressions of chlorophyll biosynthesis-related genes (HrHEMA, HrPOR and HrCAO) in Hosta have been demonstrated to be associated with leaf color. Herein, we isolated, sequenced, and analyzed HrHEMA, HrPOR and HrCAO genes. Subcellular localization was also performed to determine the location of the corresponding enzymes. After plasmid construction, virus-induced gene silencing (VIGS) was carried out to reduce the expressions of those genes. In addition, HrHEMA-, HrPOR- and HrCAO-overexpressing tobacco plants were made to verify the genes function. Changes of transgenic tobacco were recorded under 2000 lx, 6000 lx and 10,000 lx light intensity. Additionally, the contents of enzyme 5-aminolevulinic acid (5-ALA), porphobilinogen (PBG), chlorophyll a and b (Chla and Chlb), carotenoid (Cxc), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), proline (Pro) and catalase (CAT) under different light intensities were evaluated. Results The silencing of HrHEMA, HrPOR and HrCAO genes can induce leaf yellowing and chloroplast structure changes in Hosta. Specifically, leaves of Hosta with HrCAO silencing were the most affected, while those with HrPOR silencing were the least affected. Moreover, all three genes in tobacco were highly expressed, whereas no expression was detected in wild-type (WT). However, the sensitivities of the three genes to different light intensities were different. The highest expression level of HrHEMA and HrPOR was detected under 10,000 lx of illumination, while HrCAO showed the highest expression level under 6000 lx. Lastly, the 5-ALA, Chla, Cxc, SOD, POD, MDA, Pro and CAT contents in different transgenic tobaccos changed significantly under different light intensities. Conclusion The overexpression of these three genes in tobacco enhanced photosynthesis by accumulating chlorophyll content, but the influential level varied under different light intensities. Furthermore, HrHEMA-, HrPOR- and HrCAO- overexpressing in tobacco can enhance the antioxidant capacity of plants to cope with stress under higher light intensity. However, under lower light intensity, the antioxidant capacity was declined in HrHEMA-, HrPOR- and HrCAO- overexpressing tobaccos.

Sign in / Sign up

Export Citation Format

Share Document