Biomedical Engineering Reference
In-Depth Information
1800000
1600000
1400000
1200000
1000000
abs
a1
a2
b1
b2
neo
viola
lute1
lute2
fitting
A
800000
600000
400000
200000
0
400
420
440
460
480
500
520
(nm)
λ
1800000
1600000
1400000
1200000
1000000
800000
600000
B
exc
a1
a2
b1
b2
neo
viola
lute1
lute2
fitting
400000
200000
0
400
420
440
460
480
500
520
λ
(nm)
Fig. 3.5.
Deconvolution of 1-T spectra (
a
) and of fluorescence excitation spectra
(
b
) of a typical antenna protein, LHCII. The ratio of the amplitude of each spectral
form in (
b
)vs.(
a
) yields the e
ciency of excitation energy transfer from each
pigment to Chl a, the final sensitizer of photosynthesis. The figure obtained is that
light absorption by xanthophylls (vs. Chls, 350-750 nm) = 16.8%; contribution to
Chl a fluorescence by xanthophylls (vs. Chls) in trimeric LHCII = 9.9%
1. Genotypes lacking one specific carotenoid
2. Genotypes retaining only one carotenoid species
3. Genotypes lacking one or more carotenoid-binding proteins
Although not complete, a considerable collection is now available, whose
analysis will gave us a detailed functional survey. Mutant collections were
obtained both in higher plants (
A. thaliana
) and in the green algae model
organism
C. reinhardtii
. Table 3.1 includes several genotypes available, with
indications relative to laboratories that contributed to their isolation. These
mutant plants were fundamental for the initial work. Major findings are sum-
marized in the following paragraphs.
