Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2004;81(1):49-66.
doi: 10.1023/B:PRES.0000028391.70533.eb.

High-Temperature Induced Chlorophyll Fluorescence Rise in Plants at 40-50 Degrees C: Experimental and Theoretical Approach

Affiliations

High-Temperature Induced Chlorophyll Fluorescence Rise in Plants at 40-50 Degrees C: Experimental and Theoretical Approach

Roman Kouril et al. Photosynth Res. .

Abstract

We studied the temperature dependence of chlorophyll fluorescence intensity in barley leaves under weak and actinic light excitation during linear heating from room temperature to 50 degrees C. The heat-induced fluorescence rise usually appearing at around 40-50 degrees C under weak light excitation was also found in leaves treated with 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) or hydroxylamine (NH(2)OH). However, simultaneous treatment with both these compounds caused a disappearance of the fluorescence rise. We have suggested that the mechanism of the heat-induced fluorescence rise in DCMU-treated leaves is different than that in untreated or NH(2)OH-treated leaves. In DCMU-treated leaves, the heat-induced fluorescence rise reflects an accumulation of Q(A) (-) even under weak light excitation due to the thermal inhibition of the S(2)Q(A) (-) recombination as was further documented by a decrease in the intensity of the thermoluminescence Q band. Mathematical model simulating this experimental data also supports our interpretation. In the case of DCMU-untreated leaves, our model simulations suggest that the heat-induced fluorescence rise is caused by both the light-induced reduction of Q(A) and enhanced back electron transfer from Q(B) to Q(A). The simulations also revealed the importance of other processes occurring during the heat-induced fluorescence rise, which are discussed with respect to experimental data.

Similar articles

See all similar articles

Cited by 11 articles

See all "Cited by" articles

References

    1. Biochim Biophys Acta. 1978 Apr 11;502(1):138-51 - PubMed
    1. Biochemistry. 1992 Nov 24;31(46):11449-59 - PubMed
    1. Proc Natl Acad Sci U S A. 1988 Nov;85(22):8477-81 - PubMed
    1. Photosynth Res. 1990 Sep;25(3):279-93 - PubMed
    1. Biochim Biophys Acta. 1971 Nov 2;253(1):213-21 - PubMed

LinkOut - more resources

Feedback