Plant cell apoplastic peroxidase

Takahama, U. Oniki T. Shimokawa H. A possible mechanism for the oxidation of sinapyl alcohol hy peroxidase-dependent reactions in the apoplast enhancement of the oxidation hy hydroxycinnamic acids and components of the apoplast. Plant Cell Physiol. 1996, 37, 499-504. 

Martinez C, Montillet J-L, Bresson E, Agnel J-P, Dai GH, Daniel J-F, Geiger J-P, Nicole M (1998) Apoplastic peroxidase generates superoxide anions in cells of cotton cotyledons undergoing the hypersensitive reaction to Xanthomonas campestris pv. malvacearum race 18. Mol Plant Microbe Interact 11 1038-1047... 

Takahama, U., 1993b, Regulation of peroxidase-dependent oxidation of phenolics by ascorbic acid Different effects of ascorbic acid on the oxidation of conyferyl alcohol by the apoplastic soluble and cell wall-bound peroxidases from epicotyls of Vigna angularis, Plant Cell Physiol. 34 809-817. 

Although vacuolar HCAs, HBAs and flavonoids are potent antioxidants, their in vivo scavenging capacity has been questioned because they are not present in the compartments with intense ROS production. The largest part of ROS arises from electron leakage to O2 from the electron transport chains of chloroplasts and mitochondria (Asada, 1996 Moller, 2001). They additionally rise from photorespiration in peroxisomes, from apoplastic NADPH oxidases and various cell wall peroxidases. Most ROS are short-lived species (Moller etal, 2007). The mean half-life in plant tissues is estimated to be 1 o,s, 1 ps, 1 ms, and 1 ns, and their estimated traveling distances are of 30 nm, 30 nm, 1 p.m. 

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