protoporphyrin/arabidopsis

Chlorophyll biosynthesis requires a metabolic dialog between the chloroplast envelope and thylakoids where biosynthetic activities are localized. Here, we report the first plant S-adenosyl-l-methionine:Mg-protoporphyrin IX methyltransferase (MgP(IX)MT) sequence identified in the Arabidopsis genome

Chlorophyll biosynthesis is a process involving approximately 20 different enzymatic steps. Half of these steps are common to the biosynthesis of other tetrapyrroles, such as heme. One of the least understood enzymatic steps is formation of the isocyclic ring, which is a characteristic feature of

CONCLUSIONS A homologous gene of MPEC from Phyllostachys edulis was isolated and characterized. Its overexpression in Arabidopsis thaliana increased chlorophyll concentration and photosynthesis efficiency, indicating it is involved in chlorophyll biosynthesis. Magnesium-protoporphyrin IX monomethyl

To elucidate the molecular mechanisms of stomatal opening and closure, we performed a genetic screen using infrared thermography to isolate stomatal aperture mutants. We identified a mutant designated low temperature with open-stomata 1 (lost1), which exhibited reduced leaf temperature, wider

We have identified cDNA clones encoding the two Mg chelatase subunits CHL I and CHL H from tobacco (Nicotiana tabacum) by screening a cDNA library with homologous cDNA fragments from Arabidopsis thaliana. A full-length Chl I cDNA clone encodes a peptide with 426 amino acids. The entire cDNA sequence

Redox regulation is an essential post-translational regulatory mechanism in prokaryotes and eukaryotes. The reversible oxidation and reduction of cysteine residues of proteins is also important in photosynthetic organisms to control enzymatic activities, protein stability and the interaction with

The plastid plays a vital role in various cellular activities within plant cells including photosynthesis and other metabolic pathways. It is believed that the functional status of the plastid is somehow monitored by the nucleus to optimize the expression of genes encoding plastid proteins. The

Chloroplast biogenesis involves careful coordination of both plastid and nuclear gene expression, which is achieved in part by retrograde signaling from the chloroplast to the nucleus. This can be demonstrated by the fact that the herbicide, Norflurazon (NF), which causes bleaching of chloroplasts,

Genetic and physiological studies have revealed evidence for multiple signaling pathways by which the plastid exerts retrograde control over photosynthesis associated nuclear genes (PhANGs). It has been proposed that the tetrapyrrole pathway intermediate Mg-protoporphyrin IX (Mg-proto IX) acts as

Protoporphyrin IX is the last common intermediate between the heme and chlorophyll biosynthesis pathways. The addition of magnesium directs this molecule toward chlorophyll biosynthesis. The first step downstream from the branchpoint is catalyzed by the magnesium chelatase and is a highly regulated

Ferrochelatase catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme. It is located in the mitochondria in all eukaryotes and is also found in plastids in plants. Although it has been purified from animals and microorganisms, and genes for it isolated and characterized,

Protoporphyrinogen IX oxidase1 (PPO1) catalyzes the oxidation of protoporphyrinogen IX to form protoporphyrin IX in the plastid tetrapyrrole biosynthesis pathway and is also essential for plastid RNA editing in Arabidopsis thaliana. The Arabidopsis ppo1-1 mutation was previously shown to be

In plant cells, tetrapyrroles are synthesized in plastids and distributed to numerous organelles to function in various vital activities. However, molecular mechanisms of tetrapyrroles trafficking in plant cells are poorly understood. In animal cells, experimental evidence suggests that the

Protoporphyrin IX is the last common intermediate of tetrapyrrole biosynthesis. The chelation of a Mg2+ ion by magnesium chelatase and of a ferrous ion by ferrochelatase directs protoporphyrin IX towards the formation of chlorophyll and heme, respectively. A full length cDNA clone encoding a

In plants, the accumulation of the chlorophyll precursor Mg-protoporphyrin IX (Mg-Proto) in the plastid regulates the expression of a number of nuclear genes with functions related to photosynthesis. Analysis of the plastid-to-nucleus signaling activity of Mg-Proto in Arabidopsis thaliana led to the