
TY  - JOUR
A1  - Schansker, Gert 
A1  - Srivastava, Alaka 
A1  - Govindjee, 
A1  - Strasser, Reto J. 
T1  - Characterization of the 820-nm transmission signal paralleling the chlorophyll <emph type="2">a</emph> fluorescence rise (OJIP) in pea leaves
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 2003
VL  - 30
IS  - 7
SP  - 785
EP  - 796
KW  - chlorophyll fluorescence, DCMU, pea, plastocyanin, plastoquinone pool, P700, re-reduction kinetics, stromal electrons, 820-nm transmission.
UR  - https://doi.org/10.1071/FP03032 
N2  - Monitoring transmission changes at 820 nm, a measure of the redox states of plastocyanin (PC) and P700, is a good complementary technique for chlorophyll (chl) a fluorescence induction measurements. A thorough characterization of the properties of the 820-nm transmission kinetics during the first second after a dark-to-light transition is provided here for pea (Pisum sativum L.) leaves. The data indicate that plastocyanin in a dark-adapted leaf is in the reduced state. Three photosystem I (PSI)-related components, PC, P700 and ferredoxin, can contribute to the 820-nm transmission signal. The contribution of ferredoxin, however, is only approximately 5%, thus, it can be neglected for further analysis. Here, we show that by monitoring the sequential oxidation of PC and P700 during a far-red pulse and analysing the re-reduction kinetics it is possible to assign the three re-reduction components to PC (&#964; = 7&#8211;14 s) and P700 (&#964; = 35&#8211;55 ms and 1.2&#8211;1.6 s). Our data indicate that the faster re-reduction phase (&#964; = 35&#8211;55 ms) may represent a recombination reaction between P700+ and the acceptor side of PSI. This information made it possible to show that the ratio between the potential contributions of PC : P700 is 50 : 50 in pea and Camellia leaves and 40 : 60 in sugar beet leaves. 
ER  -

