PSI parameters were determined through a Dual-PAM-100 system (Heinz Walz, Effeltrich, Germany) connected to a PC with WinControl software using pulse-amplitude modulation [21]. Saturation pulses (SP) introduced primarily for PAM fluorescence measurement were also applied to assess the P700 parameters. The P700 signals (P) may vary between the minimal level (P700 fullyreduced) and the maximal level (P700 fully oxidized). The maximal P was determined by applying SP after far-red pre-illumination was conducted. Under donor-side limited conditions (produced by farred exposure), SP transiently induces full P700 oxidation. Briefly, after SP was applied, the minimal P was measured when P700 was fully reduced. The difference signal between the fully reduced and oxidized states is denoted by Pm. Actinic illumination was started, and SP was supplied every 30 s, with the same pulses used for fluorescence and P700 analyses. Each SP was followed by a 1 s dark period to determine the minimal P signal level (Po; P700 fully reduced). P was recorded prior to applying SP and briefly after SP was supplied (Pm), when the maximum P700 oxidation under the effective experimental conditions was observed, and finally at the end of the 1 s dark interval following each SP (Po determination). The signals P and Pm were compared with Po. In this way, unavoidable signal drifts (e.g., due to changes in the water status) do not
interrupt the actual measurements of P700 parameters.
PSI parameters were determined through a Dual-PAM-100 system (Heinz Walz, Effeltrich, Germany) connected to a PC with WinControl software using pulse-amplitude modulation [21]. Saturation pulses (SP) introduced primarily for PAM fluorescence measurement were also applied to assess the P700 parameters. The P700 signals (P) may vary between the minimal level (P700 fullyreduced) and the maximal level (P700 fully oxidized). The maximal P was determined by applying SP after far-red pre-illumination was conducted. Under donor-side limited conditions (produced by farred exposure), SP transiently induces full P700 oxidation. Briefly, after SP was applied, the minimal P was measured when P700 was fully reduced. The difference signal between the fully reduced and oxidized states is denoted by Pm. Actinic illumination was started, and SP was supplied every 30 s, with the same pulses used for fluorescence and P700 analyses. Each SP was followed by a 1 s dark period to determine the minimal P signal level (Po; P700 fully reduced). P was recorded prior to applying SP and briefly after SP was supplied (Pm), when the maximum P700 oxidation under the effective experimental conditions was observed, and finally at the end of the 1 s dark interval following each SP (Po determination). The signals P and Pm were compared with Po. In this way, unavoidable signal drifts (e.g., due to changes in the water status) do not
interrupt the actual measurements of P700 parameters.
การแปล กรุณารอสักครู่..
