Altered brassinolide sensitivity1 transcriptionally inhibits chlorophyll synthesis and photosynthesis capacity in tomato

Ferrochelatase is the terminal enzyme of haem biosynthesis, catalysing the insertion of ferrous iron into the macrocycle of protoporphyrin IX, the last common intermediate of haem and chlorophyll synthesis. Its activity has been reported in both plastids and mitochondria of higher plants, but the relative amounts of the enzyme in the two organelles are unknown. Ferrochelatase is difficult to assay since ferrous iron requires strict anaerobic conditions to prevent oxidation, and in photosynthetic tissues chlorophyll interferes with the quantification of the product. Accordingly, we developed a sensitive fluorimetric assay for ferrochelatase that employs Co2+ and deuteroporphyrin in place of the natural substrates, and measures the decrease in deuteroporphyrin fluorescence. A hexane-extraction step to remove chlorophyll is included for green tissue. The assay is linear over a range of chloroplast protein concentrations, with an average specific activity of 0.68nmol·min−1·mg of protein−1, the highest yet reported. The corresponding value for mitochondria is 0.19nmol·min−1·mg of protein−1. The enzyme is inhibited by N-methylprotoporphyrin, with an estimated IC50 value of ≈ 1nM. Using this assay we have quantified ferrochelatase activity in plastids and mitochondria from green pea leaves, etiolated pea leaves and pea roots to determine the relative amounts in the two organelles. We found that, in all three tissues, greater than 90% of the activity was associated with plastids, but ferrochelatase was reproducibly detected in mitochondria, at levels greater than the contaminating plastid marker enzyme, and was latent. Our results indicate that plastids are the major site of haem biosynthesis in higher plant cells, but that mitochondria also have the capacity for haem production.

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Control of chlorophyll synthesis by phytochrome

Planta ◽

10.1007/bf00399729 ◽

1976 ◽

Vol 132 (3) ◽

pp. 291-295 ◽

Cited By ~ 11

Author(s):

H. Kasemir ◽

G. Prelim

Keyword(s):

Chlorophyll Synthesis

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Thylakoid-Bound Protease Activity as Monitored by Azo-Dye Release from Azocoll Substrate is Affected by Thylakoid Development and Chlorophyll Synthesis Inhibitors

Regulation of Chloroplast Biogenesis ◽

10.1007/978-1-4615-3366-5_46 ◽

1992 ◽

pp. 331-336 ◽

Cited By ~ 2

Author(s):

Rania K. Anastassiou ◽

Joan H. Argyroudi-Akoyunoglou

Keyword(s):

Protease Activity ◽

Azo Dye ◽

Chlorophyll Synthesis ◽

Dye Release

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Bazı Üzüm Çeşitlerinde ve Asma Anaçlarında Yaprak Alanının Belirlenmesi

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v8i6.1261-1265.3149 ◽

2020 ◽

Vol 8 (6) ◽

pp. 1261-1265

Author(s):

Adem Yağcı ◽

Seda Sucu ◽

Namık Yıldız

Keyword(s):

Leaf Area ◽

Leaf Blade ◽

Optimum Level ◽

Node Number ◽

Average Value ◽

Blade Width ◽

Actual Field ◽

Photosynthesis Capacity ◽

Stem Leaf ◽

Real Area

The amount and area of the leaves should be at an optimum level in order to maintain the product quality and not to adversely affect the vine growth. Because carbohydrates, which are essential for omca and are mostly stored in fruit and wood, are formed by leaves after photosynthesis. Leaf area can be used in many areas. Among these, photosynthesis capacity and plant growth rate may. Various tools and methods (planimetry, leaf area meter, width-product, weight-area calculation, image processing programs, etc.) are used in determining leaf area. In this study, 3 American grape rootstocks (5BB, 110 R, 1103 P) and 5 grapes (Alphonse Lavallée, Italıa, Mıchele Palierı and Narince, Yalova İncisi) were used as material. 20 shoots with 15-25 nodules were taken from the rootstocks and varieties of the omca and the leaves were photocopied according to the order of the node. The actual field values of the leaves were measured with a planimeter. Leaf stem and leaf width and length of the leaves were also measured. Regression analysis was performed between leaf stem, leaf blade width and length, leaf blade × length values and real area. The maximum leaf area on one shoot was 5 BB (2484 cm2) from rootstocks and Narince (2126 cm2) from varieties. All three rootstocks gave the average value of the leaf found in 9th node. In terms of node number, which gives an average value according to the varieties, Alphonse Lavallée, Mıchele Palierı and Yalova İncisi varieties came to the forefront in 11th node. The 13th in Narince cultivar and the 12th in Italia cultivar gave the closest value to the average.

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Transcriptome Profile Analysis of Arabidopsis Reveals the Drought Stress-Induced Long Non-coding RNAs Associated With Photosynthesis, Chlorophyll Synthesis, Fatty Acid Synthesis and Degradation

Frontiers in Plant Science ◽

10.3389/fpls.2021.643182 ◽

2021 ◽

Vol 12 ◽

Author(s):

Kang Chen ◽

Yang Huang ◽

Chunni Liu ◽

Yu Liang ◽

Maoteng Li

Keyword(s):

Fatty Acid ◽

Drought Stress ◽

Fatty Acid Synthesis ◽

Oil Content ◽

Acid Synthesis ◽

Chlorophyll Synthesis ◽

Short Term ◽

Non Coding Rnas ◽

Mutant Lines

Long non-coding RNAs (lncRNAs) play an important role in the response of plants to drought stress. The previous studies have reported that overexpression of LEA3 and VOC could enhance drought tolerance and improve the oil content in Brassica napus and Arabidopsis thaliana, and most of the efforts have been invested in the gene function analysis, there is little understanding of how genes that involved in these important pathways are regulated. In the present study, the transcriptomic results of LEA3 and VOC over-expressed (OE) lines were compared with the RNAi lines, mutant lines and control lines under long-term and short-term drought treatment, a series of differentially expressed lncRNAs were identified, and their regulation patterns in mRNA were also investigated in above mentioned materials. The regulation of the target genes of differentially expressed lncRNAs on plant biological functions was studied. It was revealed that the mutant lines had less drought-response related lncRNAs than that of the OE lines. Functional analysis demonstrated that multiple genes were involved in the carbon-fixing and chlorophyll metabolism, such as CDR1, CHLM, and CH1, were regulated by the upregulated lncRNA in OE lines. In LEA-OE, AT4G13180 that promotes the fatty acid synthesis was regulated by five lncRNAs that were upregulated under both long-term and short-term drought treatments. The key genes, including of SHM1, GOX2, and GS2, in the methylglyoxal synthesis pathway were all regulated by a number of down-regulated lncRNAs in OE lines, thereby reducing the content of such harmful compounds produced under stress in plants. This study identified a series of lncRNAs related to the pathways that affect photosynthesis, chlorophyll synthesis, fatty acid synthesis, degradation, and other important effects on drought resistance and oil content. The present study provided a series of lncRNAs for further improvement of crop varieties, especially drought resistant and oil content traits.

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