Ascorbate peroxidases are haem proteins that efficiently scavenge H2O2 in the cytosol and chloroplasts of plants. Database analyses retrieved 52 expressed sequence tags coding for Arabidopsis thaliana ascorbate peroxidases. Complete sequencing of non-redundant clones revealed three novel types in addition to the two cytosol types described previously in Arabidopsis. Analysis of sequence data av...

background: elicitors can trigger defense responses and activate specific genes involved in secondary metabolite biosynthesis. objective: for understanding sa-treatment signaling pathway we determined defense-related compounds and enzymes in s. marianum hairy root cultures. methods: 28 day old hairy roots were treated by salicylic acid (6 mg/50 ml culture) for different times (24, 48, 72, 96 an...

Ruptured pea (Pisum sativum cv. Massey Gem) chloroplasts exhibited ascorbate peroxidase activity as determined by H(2)O(2)-dependent oxidation of ascorbate and ascorbate-dependent reduction of H(2)O(2). The ratio of ascorbate peroxidase to NADP-glyceraldehyde 3-phosphate dehydrogenase activity was constant during repeated washing of isolated chloroplasts. This indicates that the ascorbate perox...

We have isolated two cDNA clones encoding spinach (Spinacia oleracea) stromal and thylakoid-bound ascorbate peroxidase isoenzymes [Ishikawa, Sakai, Yoshimura, Takeda and Shigeoka (1996) FEBS Lett. 384, 289-293]. The gene (ApxII) encoding both chloroplastic ascorbate peroxidase isoenzymes was isolated and the organization of the gene was determined. Alignment between the cDNAs and the gene for c...

The lutropin-induced depletion of ascorbate in corpora lutea of albino-rat ovary is shown to be associated with the induction of peroxidase in corpora lutea. An inverse relationship between ascorbate depletion and peroxidase activity was established in a time-course study with lutropin. Analyses made at different phases of the reproductive cycle are in accord with this relationship. It is sugge...

Ascorbate levels and redox state, as well as the activities of the ascorbate related enzymes, have been analysed both in the apoplastic and symplastic spaces of etiolated pea (Pisum sativum L.) shoots during cellular differentiation. The ascorbate pool and the ascorbate oxidizing enzymes, namely ascorbate oxidase and ascorbate peroxidase, were present in both pea apoplast and symplast, whereas ...

The TL29 protein is one of the more abundant proteins in the thylakoid lumen of plant chloroplasts. Based on its sequence homology to ascorbate peroxidases, but without any supporting biochemical evidence, TL29 was suggested to be involved in the plant defense system against reactive oxygen species and consequently renamed to APX4. Our in vivo and in vitro analyses failed to show any peroxidase...

A novel, basic (isoelectric point > 10), heme peroxidase isoenzyme (TP; relative molecular weight = 34,660 +/- 10, mean +/- SE) that can account for a significant part of the ascorbate peroxidase activity in tea (Camellia sinensis) leaves has been purified to homogeneity. The ultraviolet/visible absorption spectrum is typical of heme-containing plant peroxidases, with a Soret peak at 406 nm (ep...