Phytochrome-mediated Carotenoids Biosynthesis in Ripening Tomatoes

Thomas, Ronnie L.; Jen, Joseph J.

doi:10.1104/pp.56.3.452

Cited by 50 publications

(28 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is well established that the synthesis of carotenoids is mediated by phytochrome (2,5,19,23,26), and that the syntheses of vitamin K, tocopherols, and plastoquinones are also light-controlled (28). These lipids have been shown to be synthesized in the chloroplasts (10,22).…”

Section: Discussionmentioning

confidence: 99%

“…The synthesis of several chloroplast-related isoprenoids (vitamin K, tocopherols, plastoquinone, and solanesol) is also influenced by light (28). The effect of R on promoting carotene synthesis has been shown to occur through the intermediacy of phytochrome (2,5,19,23,26). On the other hand, sterol content of light-grown Digitalis purpurea and other seedlings is one-half that of darkgrown controls (7,13).…”

mentioning

confidence: 98%

“…Exposure The biosynthesis of many terpene derivatives has been shown to be influenced by light. R has been found to stimulate carotene synthesis in etiolated seedlings of oat, barley, maize, mustard, tomatoes, and radishes (2,5,19,23,26). Synthesis of gibberellic acid, a diterpene, is enhanced by red light in wheat leaves (21).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Annual Variation in the Effect of Red Light on Sterol Biosynthesis in Digitalis purpurea L.

Jacobsohn

Orkwiszewski²,

Jacobsohn³

1978

Plant Physiol.

View full text Add to dashboard Cite

The effect of varying sequences of red and far red light on sterol biosynthesis in etiolated seedngs of Digtalis pwprea L. was examined.Red lght caused a marked increase in the amounts of free and glycosidic sterols and a small decrease in esterifled sterols during the first 4 hours after Unminatin Far red light elicited the same response but to a lesser degree. Exposure The biosynthesis of many terpene derivatives has been shown to be influenced by light. R has been found to stimulate carotene synthesis in etiolated seedlings of oat, barley, maize, mustard, tomatoes, and radishes (2,5,19,23,26). Synthesis of gibberellic acid, a diterpene, is enhanced by red light in wheat leaves (21). The synthesis of several chloroplast-related isoprenoids (vitamin K, tocopherols, plastoquinone, and solanesol) is also influenced by light (28). The effect of R on promoting carotene synthesis has been shown to occur through the intermediacy of phytochrome (2,5,19,23,26). On the other hand, sterol content of light-grown Digitalis purpurea and other seedlings is one-half that of darkgrown controls (7, 13).Sterols and carotenes are synthesized in different compartments within the cell: carotenes in the chloroplasts, and sterols in the cytoplasm (10,22 ence on carotene synthesis, it was of interest to determine whether the pigment also regulates sterol biosynthesis. We have conducted experiments over a period of 2.5 years on the effect of light on sterol content of D. purpurea seedlings. The seeds were stored in the dark at constant temperatures and the seedlings were germinated in the dark in controlled temperature rooms. Considerable variability was experienced from experiment to experiment but when the data were examined over a period of years, the effects of light appeared to follow an annual pattern. We reported previously that the sterol content of dark-grown seedlings is highest during the winter and spring and lowest during the summer and fall (14). It has now been demonstrated that the response of sterol biosynthesis to R varies inversely with the endogenous sterol content.MATERIALS AND METHODS Seeds. D. purpurea seeds were purchased from Burnett Brothers Seedsmen, New York. Three separate batches of seeds were used in these experiments. One, received in May, 1971, was used through April, 1972. The second, received in May, 1972, was used through and including June, 1973. The third, received in July, 1973, was used subsequently. The seeds were stored at 22 to 24 C in a dark room, and were not exposed to light until preparation for seeding. All three batches of seeds exhibited a period of null germination in April and May in the year of their use, but would resume germination in late May or June.Procedures have been described previously for sowing and harvesting of seedlings as well as for the extraction and preliminary separation of sterols into esterified and free plus glycoside fractions (14).Light Sources. The light sources used in these experiments were identical to those of Hopkins and Bonnell (11). The R had ...

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 98%

See 1 more Smart Citation

Annual Variation in the Effect of Red Light on Sterol Biosynthesis in Digitalis purpurea L.

Jacobsohn

Orkwiszewski²,

Jacobsohn³

1978

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…In recent years it has been observed that R2 light influences the biosynthesis of many terpene derivatives, and the involvement of phytochrome has been postulated (7,22,30 whereas sitosterol prevails under higher light intensity. Shading, however, does not influence the level of any sterol class; it generally increases stigmasterol and decreases sitosterol (16).…”

mentioning

confidence: 99%

“…In recent years it has been observed that R2 light influences the biosynthesis of many terpene derivatives, and the involvement of phytochrome has been postulated (7,22,30).…”

mentioning

confidence: 99%

Sterol Composition and Accumulation in Glycine max (L.) Merr Leaves under Different Filtered Sunlight Conditions

Izzo¹,

Navari-Izzo²

1981

Plant Physiol.

View full text Add to dashboard Cite

Light exerts a definite influence on plant metabolism in general. In recent years it has been observed that R2 light influences the biosynthesis of many terpene derivatives, and the involvement of phytochrome has been postulated (7,22,30 whereas sitosterol prevails under higher light intensity. Shading, however, does not influence the level of any sterol class; it generally increases stigmasterol and decreases sitosterol (16). The transfer of plants from long-day to short-day conditions causes a temporary decrease of sitosterol and a rise of cholesterol (1).The objectives of the investigation here were to determine the total, free, esterified, and glycosidic sterol contents and their composition, and to study the effect of different filtered sunlight conditions on sterol changes in Glycine max leaves at two different stages of plant growth.MATERIALS AND METHODS Plant Material. G. max (L.) Merr. var. Manchurica Enk-Bittherof, was planted in rows, as previously described (23, 24) LIght Measurements. Light transmittance of PVC filters, obtained before and after the experiment, with a Beckman Acta V spectrophotometer is shown in Figure 1. The PVC filters were completely opaque to UV radiation up to 320 nm. The red PVC filter showed a low transmittance below 500 nm and a very high one in the R and FR zones. The blue PVC filter transmitted weakly in R above 650 nm. An ISCO spectroradiometer (Instrumentation Specialties Co., Lincoln, NE; model SRC) was used to measure total spectral light intensity at each wavelength station in the range of 400 to 800 nm. Light conditions are delineated in Table I in which the average values of total radiation for each range of light spectrum are reported. During all plant growth, temperature and moisture were recorded inside and outside tunnels with Salmoiraghi termoigrograph (Filotecnica Salmoiraghi, Milan, Italy) and, due to ventilation arrangements, did not differ among the treatments by more than 2.5 and 5 C for the minimum and maximum values, respectively. RH inside PVC tunnels also showed no appreciable variation.

show abstract

Transcriptional regulation and DNA methylation in plastids during transitional conversion of chloroplasts to chromoplasts.

1990

View full text Add to dashboard Cite

During transitional conversion of chloroplasts to chromoplasts in ripening tomato (Lycopersicon esculentum) fruits, transcripts for several plastid genes for photosynthesis decreased to undetectable levels. Run‐on transcription of plastids indicated that transcriptional regulation operated as a predominant factor. We found that most of the genes in chloroplasts were actively transcribed in vitro by Escherichia coli and soluble plastid RNA polymerases, but some genes in chromoplasts seemed to be silent when assayed by the in vitro systems. The regulatory step, therefore, was ascribed to DNA templates. The analysis of modified base composition revealed the presence of methylated bases in chromoplast DNA, in which 5‐methylcytosine was most abundant. The presence of 5‐methylcytosine detected by isoschizomeric endonucleases and Southern hybridization was correlated with the undetectable transcription activity of each gene in the run‐on assay and in vitro transcription experiments. It is thus concluded that the suppression of transcription mediated by DNA methylation is one of the mechanisms governing gene expression in plastids converting from chloroplasts to chromoplasts.

show abstract

Phytochrome-mediated Carotenoids Biosynthesis in Ripening Tomatoes

Cited by 50 publications

References 12 publications

Annual Variation in the Effect of Red Light on Sterol Biosynthesis in Digitalis purpurea L.

Annual Variation in the Effect of Red Light on Sterol Biosynthesis in Digitalis purpurea L.

Sterol Composition and Accumulation in Glycine max (L.) Merr Leaves under Different Filtered Sunlight Conditions

Transcriptional regulation and DNA methylation in plastids during transitional conversion of chloroplasts to chromoplasts.

Contact Info

Product

Resources

About