Stimulation of chlororespiration by heat and high light intensity in oat plants.

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Quiles MJ

Stimulation of chlororespiration by heat and high light intensity in oat plants.

Plant Cell Environ. 2006 Aug;29(8):1463-70.

PubMed ID

16898010 [ View in PubMed

]

Abstract

High irradiance and moderate heat inhibit the activity of the photosynthetic apparatus of oat (Avena sativa L.) leaves. The incubation of oat leaves under high light intensity in conjunction with high temperatures strongly decreased the maximal quantum yield of photosystem (PS) II, indicating the close synergistic effect of both stress factors on PS II inhibition and the subsequent irreversible damage to the photosynthetic apparatus. The PS I A/B protein levels remained similar to control values in leaves incubated under high light intensity or moderate heat, and decreased only when both stress factors were simultaneously applied. Immunoblot analysis of thylakoid membranes using specific antibodies raised against the NDH-K subunit of the thylakoidal NADH dehydrogenase complex (NADH DH) and against plastid terminal oxidase (PTOX) revealed an increase in the amount of both proteins in response to high light intensity and/or heat treatments. In addition, these stress treatments were seen to stimulate the activity of electron donation by NADPH and ferredoxin to plastoquinone, the PTOX activity in plastoquinone oxidation and the NADH DH activity in thylakoid membranes. Incubation with n-propyl gallate (an inhibitor of PTOX) inhibited the increase of NDH-K and PTOX levels under high light intensity and heat, and slightly stimulated the activity of electron donation by NADPH and ferredoxin to plastoquinone. Antimycin A (an inhibitor of cyclic electron flow) increased the NADH DH activity and preserved the levels of NDH-K and PTOX in thylakoid membranes from leaves incubated under high light intensity and heat. The up-regulation of the PTOX and the thylakoidal NADH DH complex under these stress conditions supports a role for chlororespiration in the protection against high irradiance and moderate heat.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
NADH	NADH dehydrogenase [ubiquinone] 1 subunit C2	Protein	Humans	Unknown	Not Available	Details