Correlation of the expression of the nuclear photosynthetic gene ST-LS1 with the presence of chloroplasts.

Stockhaus, Jörg; Schell, Jeff; Willmitzer, Lothar

doi:10.1002/j.1460-2075.1989.tb08379.x

Cited by 64 publications

(41 citation statements)

References 18 publications

(31 reference statements)

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“…While light has been shown to affect the expression of genes which are positively regulated by light (e.g., rbcS) in nonphotosynthetic organs (such as root), the effects of light on expression of these genes in roots were much lower than in leaves (6,36 (19,23,28,30). When the light regulation of AS1 and AS2 genes is compared, a dramatic difference occurs in the roots, where AS2 mRNA accumulation is unaffected by light.…”

Section: Discussionmentioning

confidence: 99%

Light represses transcription of asparagine synthetase genes in photosynthetic and nonphotosynthetic organs of plants.

Tsai

Coruzzi

1991

Mol. Cell. Biol.

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Asparagine synthetase (AS) mRNA in Pisum sativum accumulates preferentially in plants grown in the dark. Nuclear run-on experiments demonstrate that expression of both the ASI and AS2 genes is negatively regulated by light at the level of transcription. A decrease in the transcriptional rate of the AS1 gene can be detected as early as 20 min after exposure to light. Time course experiments reveal that the levels of AS mRNA fluctuate dramatically during a "normal" light/dark cycle. This is due to a direct effect of light and not to changes associated with circadian rhythm. A novel finding is that the light-repressed expression of the AS1 gene is as dramatic in nonphotosynthetic organs such as roots as it is in leaves. Experiments demonstrate that the small amount of light which passes through the soil is sufficient to repress AS1 expression in roots, indicating that light has a direct effect on AS1 gene expression in roots. The negative regulation of AS gene expression by light was shown to be a general phenomenon in plants which also occurs in nonlegumes such as Nicotiana plumbaginifolia and Nicotiana tabacum. Thus, the AS genes can serve as a model with which to dissect the molecular basis for light-regulated transcriptional repression in plants.Light is the primary energy source for all living organisms on earth, excluding chemotrophs. In plants, light influences morphogenic features (phototropism and photomovement) as well as metabolic reactions (photosynthesis). Plants contain several photoreceptors that can detect light of specific wavelengths; some of these have been characterized (phytochrome), while others remain elusive (cryptochrome). The mechanism by which light signals are subsequently transferred from the photoreceptors to the target sites remains unknown.While light may act to alter plant proteins or membranes directly, at least some of the effects of light on plant development and metabolism are the results of changes in gene expression. Light has been shown to induce or repress the expression of specific photoregulated genes. Light-induced genes which have been well characterized at the molecular level include the gene families encoding the small subunit of ribulose bisphosphate carboxylase (rbcS) (6, 10-12, 14, 15, 20, 21) and the chlorophyll alb binding protein (Cab) (15,21,29,34). The light-induced expression of both the rbcS and Cab genes is regulated via phytochrome at the transcriptional level (1,28,33). Light also positively regulates the expression of plant genes which encode enzymes for nitrogen metabolism, including the nuclear genes for the chloroplast form of glutamine synthetase (GS2) (7,40), nitrate reductase (13, 27), and nitrite reductase (35). Other genes whose expression is regulated by light at the transcriptional or posttranscriptional level are ferredoxin genes (8,9) and genes encoding enzymes involved in flavonoid pigment formation, such as chalcone synthase (18,44).Light has been shown to regulate gene expression in a negative fashion for only a few identified genes (phyt...

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Section: Discussionmentioning

confidence: 99%

Light represses transcription of asparagine synthetase genes in photosynthetic and nonphotosynthetic organs of plants.

Tsai

Coruzzi

1991

Mol. Cell. Biol.

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“…A chimeric gene with a leaf-specific ST-LS1 promoter (Stockhaus et al, 1989), designed for antisense repression of the small subunit of AGPase, was transformed into transgenic potato (Solarium tuberosum L. cv Desiree) plants with repressed chloroplastic TPT (Riesmeier et al, 1993). The binary vector carrying the chimeric gene was constructed as follows: the EcoRI fragment of plasmid B22-1 (harboring the potato tuber AGPase small subunit cDNA; Miiller-Rober et al, 1990) was isolated and, after a fill-in reaction with T4 DNA polymerase, cloned into the BamHI site (blunt-ended) of a plant expression cassette containing the ST-LS1 promoter and the polyadenylation signal of the T-DNA octopine synthase gene in a pUC18-based plasmid (von Schaewen, 1989).…”

Section: Methodsmentioning

confidence: 99%

Antisense Repression of Both ADP-Glucose Pyrophosphorylase and Triose Phosphate Translocator Modifies Carbohydrate Partitioning in Potato Leaves

et al. 1997

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Previous experiments have shown that carbohydrate partitioning in leaves of potato (Solanum tuberosum L.) plants can be modified by antisense repression of the triose phosphate translocator (TPT), favoring starch accumulation during the light period, or by leafspecific antisense repression of ADP-glucose pyrophosphorylase (ACPase), reducing leaf starch content. These experiments showed that starch and sucrose synthesis can partially replace each other.To determine how leaf metabolism acclimates to an inhibition of both pathways, transgenic potato (S. tuberosum 1. cv Désirée) plants, with a 30% reduction of the TPT achieved by antisense repression, were transformed with an antisense cDNA of the small subunit of ACPase, driven by the leaf-specific ST-LS1 promoter.These double-transformed plants were analyzed with respect to their carbohydrate metabolism, and starch accumulation was reduced in all lines of these plants. In one line with a 50% reduction of AGPase activity, the rate of CO, assimilation was unaltered. In these plants the stromal level of triose phosphate was increased, enabling a high rate of triose phosphate export in spite of the reduction of the TPT protein by antisense repression. In a second line with a 95% reduction of ACPase activity, the amount of chlorophyll was significantly reduced as a consequence of the lowered triose phosphate utilization capacity.

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“…Thus, photooxidation may act on the site of synthesis of this signal but does not affect the function of other trans-acting factors required for the transcription of nuclear genes for nonplastid proteins. In support of this theory, the expression of a nuclear-encoded chloroplast-localized protein has been tightly correlated with the presence of chloroplasts at the level of individual cells (33).…”

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confidence: 87%

Regulation of Plastid Gene Expression during Photooxidative Stress

Tonkyn¹,

Deng²,

Gruissem³

1992

Plant Physiol.

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We have used the carotenoid biosynthesis inhibitor norflurazon to study the relationship between chloroplast and nuclear gene expression and the mechanisms by which plastid mRNA accumulation is regulated in response to photooxidative stress. By treating 4-week-old hydroponic spinach plants (Spinacea oleracea), we were able to determine the response at two distinct stages of chloroplast development. For all parameters studied, differences were found between the norflurazon-treated young and mature leaves. Young leaves lost essentially all pigment content in the presence of norflurazon, whereas mature leaves retained more than 60% of their chlorophyll and carotenoids. The accumulation of plastid mRNA was determined for several genes, and we found a decrease in mRNA levels for all genes except psbA in herbicidetreated young leaves. For genes such as atpB, psbB, and psaA, there was a corresponding change in the relative level of transcription, but for psbA and rbcL, transcription and mRNA accumulation were uncoupled. In norflurazon-treated mature leaves, all plastid mRNAs except psaA accumulated to normal levels, and transcription levels were either normal or higher than corresponding controls. This led to the conclusion that plastid mRNA accumulation is regulated both transcriptionally and posttranscriptionally in response to photooxidative stress. Although direct photooxidative damage is confined to the plastid and peroxisome, there is a feedback of information controlling the transcription of nuclearencoded plastid proteins. Considerable evidence has accumulated implicating a "plastid factor" in this control. Therefore, the expression of several nuclear-encoded plastid proteins and the corresponding mRNAs were determined. Although the levels of both the small subunit of ribulose-1,5-bisphosphate carboxylase and the light harvesting chlorophyll a/b-binding protein and corresponding mRNAs were reduced, a 28-kilodalton chloroplast RNA-binding protein and corresponding mRNA were at normal levels in norflurazon-treated plants. Changes in mRNA and protein levels were not the result of a general loss due to photooxidation but rather the result of selective stabilization of certain components. The response of both genomes to photooxidative stress is discussed in terms of the postulated plastid factor.Carotenoids in higher plants protect Chl from photooxidation under normal or high light conditions (1). There is 'This work was supported by the

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Correlation of the expression of the nuclear photosynthetic gene ST-LS1 with the presence of chloroplasts.

Cited by 64 publications

References 18 publications

Light represses transcription of asparagine synthetase genes in photosynthetic and nonphotosynthetic organs of plants.

Light represses transcription of asparagine synthetase genes in photosynthetic and nonphotosynthetic organs of plants.

Antisense Repression of Both ADP-Glucose Pyrophosphorylase and Triose Phosphate Translocator Modifies Carbohydrate Partitioning in Potato Leaves

Regulation of Plastid Gene Expression during Photooxidative Stress

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