Action of bicarbonate and Photosystem 2 inhibiting herbicides on electron transport in pea grana and in thylakoids of a blue‐green alga

Jack J.S. van Rensen, Willem Vermaas

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

Bicarbonate (or carbon dioxide) is required for electron transport in isolated broken pea chloroplasts. The site of action of the bicarbonate ion is between the primary electron acceptor of Photosystem 2, Q, and the plastoquinone pool. After trypsin treatment the Hill reaction with ferricyanide does not require bicarbonate. Photosystem 2 inhibiting herbicides act also at this site. Therefore, a possible interaction of bicarbonate and these herbicides in their effect on photosynthetic electron transport was studied. The reciprocal of the Hill reaction rate in CO2‐depleted chloroplasts was plotted against the reciprocal of added bicarbonate concentration in the absence and in the presence of 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU), 2‐methoxy‐4,6‐bis (ethylamino)‐1,3,5‐triazine (simeton) or 4,6‐dinitro‐o‐cresol (DNOC). From these Lineweaver‐Burk plots we concluded that DCMU and simeton inhibit both bicarbonate binding and Vmax. There is a purely competitive inhibition of bicarbonate binding by DNOC. We suggest that DNOC may exert its inhibition of electron transport by removing bicarbonate from its binding site. In isolated thylakoid membranes of Synechococcus leopoliensis we did not find a bicarbonate effect nor inhibition by DNOC after Q, indicating that in the thylakoids of this blue‐green alga the binding site for bicarbonate and DNOC between Q and plastoquinone is absent.

Original languageEnglish (US)
Pages (from-to)106-110
Number of pages5
JournalPhysiologia Plantarum
Volume51
Issue number1
DOIs
StatePublished - 1981
Externally publishedYes

Fingerprint

algae
grana
Thylakoids
Peas
Herbicides
Bicarbonates
Electron Transport
bicarbonates
thylakoids
electron transfer
peas
DNOC (pesticide)
herbicides
Plastoquinone
Diuron
Chloroplasts
binding sites
Synechococcus leopoliensis
chloroplasts
Binding Sites

Keywords

  • bicarbonate
  • Chloroplast
  • electron transport
  • mechanism of action of herbicides
  • Synechococcus
  • trypsin

ASJC Scopus subject areas

  • Physiology
  • Genetics
  • Plant Science
  • Cell Biology

Cite this

@article{28a083caebe448ef9fb97e28899dc193,
title = "Action of bicarbonate and Photosystem 2 inhibiting herbicides on electron transport in pea grana and in thylakoids of a blue‐green alga",
abstract = "Bicarbonate (or carbon dioxide) is required for electron transport in isolated broken pea chloroplasts. The site of action of the bicarbonate ion is between the primary electron acceptor of Photosystem 2, Q, and the plastoquinone pool. After trypsin treatment the Hill reaction with ferricyanide does not require bicarbonate. Photosystem 2 inhibiting herbicides act also at this site. Therefore, a possible interaction of bicarbonate and these herbicides in their effect on photosynthetic electron transport was studied. The reciprocal of the Hill reaction rate in CO2‐depleted chloroplasts was plotted against the reciprocal of added bicarbonate concentration in the absence and in the presence of 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU), 2‐methoxy‐4,6‐bis (ethylamino)‐1,3,5‐triazine (simeton) or 4,6‐dinitro‐o‐cresol (DNOC). From these Lineweaver‐Burk plots we concluded that DCMU and simeton inhibit both bicarbonate binding and Vmax. There is a purely competitive inhibition of bicarbonate binding by DNOC. We suggest that DNOC may exert its inhibition of electron transport by removing bicarbonate from its binding site. In isolated thylakoid membranes of Synechococcus leopoliensis we did not find a bicarbonate effect nor inhibition by DNOC after Q, indicating that in the thylakoids of this blue‐green alga the binding site for bicarbonate and DNOC between Q and plastoquinone is absent.",
keywords = "bicarbonate, Chloroplast, electron transport, mechanism of action of herbicides, Synechococcus, trypsin",
author = "{van Rensen}, {Jack J.S.} and Willem Vermaas",
year = "1981",
doi = "10.1111/j.1399-3054.1981.tb00886.x",
language = "English (US)",
volume = "51",
pages = "106--110",
journal = "Physiologia Plantarum",
issn = "0031-9317",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Action of bicarbonate and Photosystem 2 inhibiting herbicides on electron transport in pea grana and in thylakoids of a blue‐green alga

AU - van Rensen, Jack J.S.

AU - Vermaas, Willem

PY - 1981

Y1 - 1981

N2 - Bicarbonate (or carbon dioxide) is required for electron transport in isolated broken pea chloroplasts. The site of action of the bicarbonate ion is between the primary electron acceptor of Photosystem 2, Q, and the plastoquinone pool. After trypsin treatment the Hill reaction with ferricyanide does not require bicarbonate. Photosystem 2 inhibiting herbicides act also at this site. Therefore, a possible interaction of bicarbonate and these herbicides in their effect on photosynthetic electron transport was studied. The reciprocal of the Hill reaction rate in CO2‐depleted chloroplasts was plotted against the reciprocal of added bicarbonate concentration in the absence and in the presence of 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU), 2‐methoxy‐4,6‐bis (ethylamino)‐1,3,5‐triazine (simeton) or 4,6‐dinitro‐o‐cresol (DNOC). From these Lineweaver‐Burk plots we concluded that DCMU and simeton inhibit both bicarbonate binding and Vmax. There is a purely competitive inhibition of bicarbonate binding by DNOC. We suggest that DNOC may exert its inhibition of electron transport by removing bicarbonate from its binding site. In isolated thylakoid membranes of Synechococcus leopoliensis we did not find a bicarbonate effect nor inhibition by DNOC after Q, indicating that in the thylakoids of this blue‐green alga the binding site for bicarbonate and DNOC between Q and plastoquinone is absent.

AB - Bicarbonate (or carbon dioxide) is required for electron transport in isolated broken pea chloroplasts. The site of action of the bicarbonate ion is between the primary electron acceptor of Photosystem 2, Q, and the plastoquinone pool. After trypsin treatment the Hill reaction with ferricyanide does not require bicarbonate. Photosystem 2 inhibiting herbicides act also at this site. Therefore, a possible interaction of bicarbonate and these herbicides in their effect on photosynthetic electron transport was studied. The reciprocal of the Hill reaction rate in CO2‐depleted chloroplasts was plotted against the reciprocal of added bicarbonate concentration in the absence and in the presence of 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU), 2‐methoxy‐4,6‐bis (ethylamino)‐1,3,5‐triazine (simeton) or 4,6‐dinitro‐o‐cresol (DNOC). From these Lineweaver‐Burk plots we concluded that DCMU and simeton inhibit both bicarbonate binding and Vmax. There is a purely competitive inhibition of bicarbonate binding by DNOC. We suggest that DNOC may exert its inhibition of electron transport by removing bicarbonate from its binding site. In isolated thylakoid membranes of Synechococcus leopoliensis we did not find a bicarbonate effect nor inhibition by DNOC after Q, indicating that in the thylakoids of this blue‐green alga the binding site for bicarbonate and DNOC between Q and plastoquinone is absent.

KW - bicarbonate

KW - Chloroplast

KW - electron transport

KW - mechanism of action of herbicides

KW - Synechococcus

KW - trypsin

UR - http://www.scopus.com/inward/record.url?scp=84989672010&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84989672010&partnerID=8YFLogxK

U2 - 10.1111/j.1399-3054.1981.tb00886.x

DO - 10.1111/j.1399-3054.1981.tb00886.x

M3 - Article

VL - 51

SP - 106

EP - 110

JO - Physiologia Plantarum

JF - Physiologia Plantarum

SN - 0031-9317

IS - 1

ER -