[Analysis of Chlorophyll Fluorescence Transient by Spectral Multi-exponential Approximation]

Area of Science:

• Plant physiology
• Biophysics
• Spectroscopy

Context:

• Chlorophyll fluorescence transients provide insights into photosynthetic processes.
• Current methods for analyzing fluorescence induction curves rely on semi-empirical approaches.
• Identifying distinct phases in fluorescence transients is crucial for understanding plant stress responses.

Purpose:

• To introduce a novel mathematical method for analyzing chlorophyll fluorescence transients.
• To enable more objective and rigorous identification of fluorescence induction curve phases.
• To apply this method for early stress detection in plants.

Summary:

• This study describes a method for analyzing chlorophyll fluorescence transients by approximating the measured signal with a multi-exponential series.
• Visualizing partial sums of the series allows for the determination of amplitudes and characteristic times of individual phases.
• This approach offers more robust criteria for phase identification compared to existing semi-empirical methods.

Impact:

• The method was successfully applied to *Chlamidomonas reinhardtii* under sulfur deprivation.
• It demonstrated efficiency in detecting visually indistinguishable phases of the fluorescence transient.
• This facilitates earlier detection of stress in plants, improving physiological monitoring.