965 
ing 7.1, 46.9 and 65.0 
hown in Fig. 6 . The 
ncrease of chlorophyll 
lions of F680 and F685 
: chlorophyll contents 
Ition. 
scence varied among a 
d chlorina mutant plants 
nd almost completely 
b, which have similar 
r, P700 (Kano, 1987). 
es of the mutant plants 
defect of chlorophyll b, 
lecreased in the chlorina 
defects in chlorophyll b 
a the two peaks was the 
a of the chlorina mutant 
I b (MGS- 88 ) showed a 
a 
b 
I I ■ 
D 780 810 
H (nm) 
ence spectra of rice wild- 
; (a) 65.0 nmol cm . 0 >) 
nmol cm " 2 chlorophylls- 
by the Ar laser light (477 
0 20 40 60 
CHLOROPHYLL CONTENTS (nmol/cm 2 ) 
Fig. 7 Relationship between the Fi/F» ratio and 
chlorophyll content of rice wild-type plant leaves. 
Chlorophyll contents in the leaves were varied by 
controlling the supply of nutrients. The data used were 
the same as Fig. 6 . 
broad top with little humps at Fi and Fn positions (Fig. 
8 c). Relationships between chlorophyll a/b ratio and 
proportion of emitters in fluorescence spectra are shown 
in Fig. 9. The F680, F685 and F745 decreased and F695 
and F725 increased according to the increase of the 
chlorophyll a/b ratio. 
Spectra induced by 693 nm diode-laser light in leaves 
of the wild-type rice plant (Norm 8 ) and the chlorina 
mutant plant (MGS- 88 ) (Fig. 10) were measured. The 
spectra were overlapped with those of the laser light 
(693 nm), therefore, the signal of the excitation light was 
subtracted by a computer. Large Fi peaks were 
observed, while the ranges of the Fn peaks around 693 
nm were null from characteristics of the spectrometer 
and the data processing system used, by which signals of 
high intensity in the region of the excitation light were 
out of scale in order to measure weak signals of 
fluorescence. Considering slopes at both sides of the 
region, the Fn peaks are surmised to be not large. In the 
spectrum of the wild-type plant, a steep emission peak 
was detected at 745 nm while a gentle slope from 
710 nm to 740 nm was observed in the spectrum of the 
chlorina mutant plant (Fig. 10), which corresponded to 
the results of Fig. 8 . 
4. DISCUSSION 
Chlorophyll fluorescence induced by Ar (477 & 
^88 nm) laser light showed two peaks around 685 nm 
(Fn) and 740 nm (Fi). The spectral profile changed with 
chlorophyll content of leaves (Fig. 6 ) as reported by 
Kocsa nyi et al. (1988), Rinderle & Lichtenthaler (1988) 
Md Takahashi et al. (1991); intensity of the Fi peak 
»gainst that of the F» peak (the Fi/Fn ratio) was 
elevated with the increase of chlorophyll content of 
leaves (Fig. 7). The spectral profile was also changed by 
other factors, high temperature (Figs.1 & 2), fumigations 
of air-pollutants (Figs. 3 & 4), preilluminations of 
photosystem II (Fig. 5), and genetic inheritances of 
photosystems (Figs. 8 & 9). To obtain clues to analyze 
the spectral changes, we resolved the spectra into 
tentative Gaussian emitter components, F680, F685, 
F695, F725, F745 and other one or two minor emitters al 
longer wavelengths (Takahashi et al., 1991; 
Wittmershaus et al., 1985). Although it has to be taken 
into account that the spectra are severely distorted in the 
region of the Fn peak from self-absorption of 
fluorescence by dense pigments in intact leaves, this 
direction of approach may provide useful information to 
understand the changes. 
Leaves of rice chlorina mutant plants are partly or 
almost completely deficient in chlorophyll b associated 
with loss of light-harvesting peripheral antenna 
chlorophylls (Kano, 1987; Kano et al., 1988). Spectral 
changes of chlorophyll fluorescence in relation to 
chlorophyll contents were different in the chlorina 
mutant plants (Figs. 8 & 9) from in the wild-type rice 
plant (Figs. 6 & 7). The Fi/Fn ratio lowered with the 
decrease of chlorophyll content in the wild-type plant 
while the bend between the two peaks became shallow 
without lowering the Fi/Fn ratio, in spite of the decrease 
of chlorophyll content and self-absorption of the Fn peak 
in the mutant plants. Reduced emissions from F680, 
F685 and F745 in the mutant plants suggest that F680, 
F685 and F745 are closely related to light-harvesting 
peripheral antennas, and F695 and F725 core antennas. 
Spectra induced by 693 nm diode-laser light (Fig. 10) 
which preferentially excites photosystem I (Koizumi et 
al., 1990) demonstrated fluorescence at longer 
wavelengths than 700 nm, where fluorescence of 
photosystem I is located at low temperature 
(Wittmershaus et al., 1985). Hence, emissions of F725 
and F745 are ascribed to emitters related to photosystem 
I (Holzwarth et al., 1990; Marchiarullo & Ross, 1985), 
even if they include vibrational bands of emitters related 
to photosystem II (Seely & Connolly, 1986). The 
finding that pre illuminations of photosystem II brought 
about from a 25 to 30% decrease of proportions of F680 
and F685 and a slight (15%) increase of F745 (Figs. 
5b, c & d), suggests that light-harvesting peripheral 
antennas migrate from photosystem II to photosystem I 
(Islam, 1987; Telfer et al., 1984) by the state transition 
(Canaani & Malkin, 1984; Fork & Sat oh, 1986). Based 
on these results, F680 and F685 are considered to be 
related to peripheral antenna of photosystem II, F695 
core antenna of photosystem II, F725 mainly core 
antenna of photosystem I including possible vibrational 
bands of photosystem II, and F745 mainly peripheral 
antenna of photosystem I including possible vibrational 
bands of photosystem II. The emissions of longer 
wavelengths than 750 nm (Rijgersberg et al., 1979) are 
considered to be ascribed to vibrational bands of 
photosystem I (Oquist & Fork, 1982). 
Light capture by peripheral antennas of photosystem 
D (F680 and F685) was considered to be affected at 45 °C