Biomaterial Database

The chloroplast Ndh complex mediates the dark reduction of the plastoquinone pool in response to heat stress in tobacco leaves. 1998

L A Sazanov, and P A Burrows, and P J Nixon

Department of Biochemistry, Imperial College of Science, Technology and Medicine, London, UK.

We have examined the effects of heat stress on electron transfer in the thylakoid membrane of an engineered plastid ndh deletion mutant, delta1, incapable of performing the Ndh-mediated reduction of the plastoquinone pool in the chloroplast. Upon heat stress in the dark, the rate of PSII-independent reduction of PSI after subsequent illumination by far-red light is dramatically enhanced in both delta1 and a wild-type control plant (WT). In contrast, in the dark, only the WT shows an increase in the reduction state of the plastoquinone pool. We conclude that the heat stress-induced reduction of the intersystem electron transport chain can be mediated by Ndh-independent pathways in the light but that in the dark the dominant pathway for reduction of the plastoquinone pool is catalysed by the Ndh complex. Our results therefore demonstrate a functional role for the Ndh complex in the dark.

UI	MeSH Term	Description	Entries
D010940	Plant Proteins	Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which PLANT PROTEINS, DIETARY is available.	Plant Protein,Protein, Plant,Proteins, Plant
D010947	Plants, Toxic	Plants or plant parts which are harmful to man or other animals.	Plants, Poisonous,Plant, Poisonous,Plant, Toxic,Poisonous Plant,Poisonous Plants,Toxic Plant,Toxic Plants
D010971	Plastoquinone	Polyunsaturated side-chain quinone derivative which is an important link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.	Plastoquinone-9,Plastoquinone 9
D002734	Chlorophyll	Porphyrin derivatives containing magnesium that act to convert light energy in photosynthetic organisms.	Phyllobilins,Chlorophyll 740
D002736	Chloroplasts	Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.	Chloroplast,Etioplasts,Etioplast
D014026	Nicotiana	A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; the dried leaves of Nicotiana tabacum are used for SMOKING.	Tobacco Plant,Nicotiana tabacum,Plant, Tobacco,Plants, Tobacco,Tobacco Plants
D018882	Heat Stress Disorders	A group of conditions that develop due to overexposure or overexertion in excessive environmental heat.	Exertional Heat Illness,Exertional Heat Stress,Heat Cramps,Heat Fatigue,Heat Illness,Heat Stress Syndromes,Heat Syncope,Stress Disorders, Heat,Exertional Heat Illnesses,Exertional Heat Stresses,Fatigue, Heat,Heat Cramp,Heat Fatigues,Heat Illness, Exertional,Heat Illnesses,Heat Stress Disorder,Heat Stress Syndrome,Heat Stress, Exertional,Heat Syncopes,Illness, Heat,Stress Disorder, Heat,Stress Syndrome, Heat,Syncope, Heat