Free radical involvement in the generation of trans-root potential
Апстракт
The identity of the naturally occurring compounds that accept electrons from plasma membrane-bound redox systems in vivo is obscure. We analysed the effect of ascorbate, oxygen, iron, as well as their free radical forms, and also the free radical-generating and -quenching systems on the trans-root electrical potential, which had previously been shown to be coupled to plasma membrane-bound redox systems. The material was the primary root of 8-day-old maize (Zea mays L.) seedlings. Trans-root electrical potential difference was measured across excised roots. Different ascorbate (ascorbate, dehydroascorbate and ascorbate free radical) and oxygen redox forms (superoxide and hydroxide radicals and hydrogen peroxide), as well as scavenging agents of oxygen species (superoxide dismutase, catalase, mannitol), and ferric and ferrous ions were added to the solution flowing around the root. Ascorbate free radical induced the greatest depolarization of the trans-root potential when compared to oth...er ascorbate redox forms, which is consistent with its suggested role as a natural electron acceptor. Addition of xanthine oxidase, with or without xanthine, also produced depolarizing effects. The presence of SOD magnified this effect both with ascorbate free radical and xanthine oxidase. When ferric or ferrous chloride and ferric EDTA were applied to the bathing medium, only free ferric ion produced a very pronounced depolarization. The magnitude and kinetics of trans-root potential depolarization, induced by the ascorbate redox forms and systems for the generation and scavenging of oxygen species, argue in favour of the mutually competing electron transfer role of ascorbate free radicals and superoxide radicals in the extracellular space of the root. These results provide evidence that at least a part of the electrical potential difference occurring across plant roots arises from current flow from the symplast, via the plasma membrane-bound redox systems, to naturally occurring compounds in the apoplast, and that this transfer is achieved through the mediation of their free radical forms.
Кључне речи:
Zea mays / trans-root potential / free radicals / ascorbate / oxygen species / symplast / apoplastИзвор:
Physiologia Plantarum, 1998, 104, 4, 777-782Издавач:
- Wiley, Hoboken
DOI: 10.1034/j.1399-3054.1998.1040438.x
ISSN: 0031-9317
WoS: 000078536300039
Scopus: 2-s2.0-0032466756
Институција/група
Institut za multidisciplinarna istraživanjaTY - JOUR AU - Vuletic, M AU - Radotić, Ksenija AU - Vučinić, Željko PY - 1998 UR - http://rimsi.imsi.bg.ac.rs/handle/123456789/39 AB - The identity of the naturally occurring compounds that accept electrons from plasma membrane-bound redox systems in vivo is obscure. We analysed the effect of ascorbate, oxygen, iron, as well as their free radical forms, and also the free radical-generating and -quenching systems on the trans-root electrical potential, which had previously been shown to be coupled to plasma membrane-bound redox systems. The material was the primary root of 8-day-old maize (Zea mays L.) seedlings. Trans-root electrical potential difference was measured across excised roots. Different ascorbate (ascorbate, dehydroascorbate and ascorbate free radical) and oxygen redox forms (superoxide and hydroxide radicals and hydrogen peroxide), as well as scavenging agents of oxygen species (superoxide dismutase, catalase, mannitol), and ferric and ferrous ions were added to the solution flowing around the root. Ascorbate free radical induced the greatest depolarization of the trans-root potential when compared to other ascorbate redox forms, which is consistent with its suggested role as a natural electron acceptor. Addition of xanthine oxidase, with or without xanthine, also produced depolarizing effects. The presence of SOD magnified this effect both with ascorbate free radical and xanthine oxidase. When ferric or ferrous chloride and ferric EDTA were applied to the bathing medium, only free ferric ion produced a very pronounced depolarization. The magnitude and kinetics of trans-root potential depolarization, induced by the ascorbate redox forms and systems for the generation and scavenging of oxygen species, argue in favour of the mutually competing electron transfer role of ascorbate free radicals and superoxide radicals in the extracellular space of the root. These results provide evidence that at least a part of the electrical potential difference occurring across plant roots arises from current flow from the symplast, via the plasma membrane-bound redox systems, to naturally occurring compounds in the apoplast, and that this transfer is achieved through the mediation of their free radical forms. PB - Wiley, Hoboken T2 - Physiologia Plantarum T1 - Free radical involvement in the generation of trans-root potential EP - 782 IS - 4 SP - 777 VL - 104 DO - 10.1034/j.1399-3054.1998.1040438.x ER -
@article{ author = "Vuletic, M and Radotić, Ksenija and Vučinić, Željko", year = "1998", abstract = "The identity of the naturally occurring compounds that accept electrons from plasma membrane-bound redox systems in vivo is obscure. We analysed the effect of ascorbate, oxygen, iron, as well as their free radical forms, and also the free radical-generating and -quenching systems on the trans-root electrical potential, which had previously been shown to be coupled to plasma membrane-bound redox systems. The material was the primary root of 8-day-old maize (Zea mays L.) seedlings. Trans-root electrical potential difference was measured across excised roots. Different ascorbate (ascorbate, dehydroascorbate and ascorbate free radical) and oxygen redox forms (superoxide and hydroxide radicals and hydrogen peroxide), as well as scavenging agents of oxygen species (superoxide dismutase, catalase, mannitol), and ferric and ferrous ions were added to the solution flowing around the root. Ascorbate free radical induced the greatest depolarization of the trans-root potential when compared to other ascorbate redox forms, which is consistent with its suggested role as a natural electron acceptor. Addition of xanthine oxidase, with or without xanthine, also produced depolarizing effects. The presence of SOD magnified this effect both with ascorbate free radical and xanthine oxidase. When ferric or ferrous chloride and ferric EDTA were applied to the bathing medium, only free ferric ion produced a very pronounced depolarization. The magnitude and kinetics of trans-root potential depolarization, induced by the ascorbate redox forms and systems for the generation and scavenging of oxygen species, argue in favour of the mutually competing electron transfer role of ascorbate free radicals and superoxide radicals in the extracellular space of the root. These results provide evidence that at least a part of the electrical potential difference occurring across plant roots arises from current flow from the symplast, via the plasma membrane-bound redox systems, to naturally occurring compounds in the apoplast, and that this transfer is achieved through the mediation of their free radical forms.", publisher = "Wiley, Hoboken", journal = "Physiologia Plantarum", title = "Free radical involvement in the generation of trans-root potential", pages = "782-777", number = "4", volume = "104", doi = "10.1034/j.1399-3054.1998.1040438.x" }
Vuletic, M., Radotić, K.,& Vučinić, Ž.. (1998). Free radical involvement in the generation of trans-root potential. in Physiologia Plantarum Wiley, Hoboken., 104(4), 777-782. https://doi.org/10.1034/j.1399-3054.1998.1040438.x
Vuletic M, Radotić K, Vučinić Ž. Free radical involvement in the generation of trans-root potential. in Physiologia Plantarum. 1998;104(4):777-782. doi:10.1034/j.1399-3054.1998.1040438.x .
Vuletic, M, Radotić, Ksenija, Vučinić, Željko, "Free radical involvement in the generation of trans-root potential" in Physiologia Plantarum, 104, no. 4 (1998):777-782, https://doi.org/10.1034/j.1399-3054.1998.1040438.x . .