Fluorescence emission spectra of chloroplasts and subchloroplast preparations at low temperature

Rijgersberg, C.P.; Amesz, J.; Thielen, A.P.G.M.; Swager, J.A.

doi:10.1016/0005-2728(79)90156-7

Cited by 103 publications

(46 citation statements)

References 31 publications

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“…The predominating emission band at 737 nm originates from the heterodimeric PSI antenna complex comprising Lhca1 and Lhca4 (17). Minor emission spectral bands, namely the 685-nm and 695-nm bands, that emanate from the PSII core antenna complexes known as CP43 and CP47, respectively (18,19), are not the focus of this spectral profile that emphasizes the dominant longer wavelength band(s). The spectral contour, dominated by the 737-nm emission exhibits excitation maxima at 442 nm and 472 nm from Chls a and b, respectively.…”

Section: Resultsmentioning

confidence: 99%

Protection and storage of chlorophyll in overwintering evergreens

Gilmore

Ball

2000

Proc. Natl. Acad. Sci. U.S.A.

164

132

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How evergreen species store and protect chlorophyll during exposure to high light in winter remains unexplained. This study reveals that the evergreen snow gum (Eucalyptus pauciflora Sieb. ex Spreng.) stores and protects its chlorophylls by forming special complexes that are unique to the winter-acclimated state. Our in vivo spectral and kinetic characterizations reveal a prominent component of the chlorophyll fluorescence spectrum around 715 nm at 77 K. This band coincides structurally with a loss of chlorophyll and an increase in energy-dissipating carotenoids. Functionally, the band coincides with an increased capacity to dissipate excess light energy, absorbed by the chlorophylls, as heat without intrathylakoid acidification. The increased heat dissipation helps protect the chlorophylls from photo-oxidative bleaching and thereby facilitates rapid recovery of photosynthesis in spring.U nder favorable light and temperatures, most plants operate with a high quantum efficiency (better than 80%) to use absorbed photons to catalyze photosynthetic electron transport, ATP synthesis, and carbon fixation. However, photosynthetic efficiency in leaves of evergreens such as holly (1), pines (2, 3), and snow gum (4, 5), naturally declines to very low levels during winter and remains inhibited until conditions become favorable for growth in spring. These evergreen species maintain significant levels of chlorophyll (Chl), which exists in a state that has not been characterized previously with respect to the Chl electronic-excited state or fluorescence lifetimes, or the Chl excitation vs. emission spectra of photosystems I and II (PSI and PSII). This characterization is essential for understanding mechanisms of Chl protection and storage in overwintering evergreens.We report that winter acclimation of the photosynthetic apparatus in the snow gum Eucalyptus pauciflora Sieb. ex Spreng results in a large loss of Chl in the leaf and profound changes in the Chl a fluorescence emission spectrum at 77 K in the form of a broad emission maximum featured in the 715-nm region. Concomitantly there is a significant increase in the amplitudes of room temperature PSII Chl a fluorescence emission components with subnanosecond fluorescence lifetimes. The subnanosecond lifetime components indicate a more rapid rate of thermal excitation dissipation compared to the main 2.5-ns components (6) that typify the deacclimated state. Although the spectral and kinetic changes during winter acclimation are induced by excess light and chloroplast intrathylakoid acidification (6, 7), the slowly reversing changes during deacclimation are sustained largely independently of intrathylakoid acidification. The enhanced thermal dissipation during winter acclimation correlates with a massive build-up of the same xanthophyll cycle pigments (8) that are most widely known to correlate with PSII thermal dissipation when there is intrathylakoid acidification (6,7,(9)(10)(11)(12). The primary steps of winter deacclimation correlate with a slow, stoichiometric conversi...

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Section: Resultsmentioning

confidence: 99%

Protection and storage of chlorophyll in overwintering evergreens

Gilmore

Ball

2000

Proc. Natl. Acad. Sci. U.S.A.

164

132

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“…Low temperature fluorescence emission spectra for plastids isolated from the fully blocked mutants hcf*-3, hcf*-19G, and wild-type seedlings are presented in Figure 4. At 77 K, maize plastids show the characteristic three banded fluorescence emission spectrum typical of a variety of photosynthetic organisms (33) with emission peaks at approximately 685 (F685), 695 (F695), and 735 nm (F735). In wild-type maize plastids F695 is typically seen as a small shoulder (33).…”

Section: Resultsmentioning

confidence: 99%

“…At 77 K, maize plastids show the characteristic three banded fluorescence emission spectrum typical of a variety of photosynthetic organisms (33) with emission peaks at approximately 685 (F685), 695 (F695), and 735 nm (F735). In wild-type maize plastids F695 is typically seen as a small shoulder (33). Plastids from the fully blocked mutants hcf*-3 and hcf*-19G show a markedly increased fluorescence yield at 696 nm relative to wild-type (Fig.…”

Section: Resultsmentioning

confidence: 99%

Characterization of Three Photosystem II Mutants in Zea mays L. Lacking a 32,000 Dalton Lamellar Polypeptide

Leto¹,

Miles²

1980

Plant Physiol.

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Two fully blocked and one partially blocked photosystem II nuclear mutants have been selected in Zea mays. The fully blocked mutants lack photosystem II activity, variable fluorescence, the light-inducible C-550 signal, the high potential form of cytochrome b-559, and most or all of the low potential form of the cytochrome. The block in these mutants may primarily affect the reducing side of photosystem II, inasmuch as chloroplasts isolated from both mutants exhibit an elevated F695 fluorescence emission peak. The partially blocked mutant exhibits partial photosystem 11 activity and a reduction, but not the total loss of the variable fluorescence yield, the C-550 signal, and the high potential form of cytochrome b-559. Lamellae isolated from the fully blocked mutants are greatly deficient for a major lamellar polypeptide with an apparent molecular weight of 32,000 daltons, whereas lamellae from the partially blocked mutant show the partial loss of this same polypeptide, suggesting that the 32,000 dalton polypeptide is necessary for the proper function of photosystem I.Genetic mutants are useful tools for the study of photosynthesis, as has been amply documented in the classic work with algal photosynthetic mutants (22). However, with the exception of the large collection of well characterized pigment mutants in barley (17, 36), the number of photosynthesis mutants studied in any single species of flowering plant has been relatively small. To date, most higher plant photosynthesis mutants are characterized by gross pigment losses which are often accompanied by major alterations in thylakoid membrane morphology and the loss of many lamellar polypeptides (9,15,36,37). Recently, a large collection of photosynthesis mutants was obtained in Zea mays (28) using elevated levels of Chl fluorescence to screen specifically for mutants blocked in photosynthesis (29). By employing this technique, both fully green and yellow-green nuclear mutants with blocks in electron transport, photophosphorylation, and dark reactions have been identified (26,28).The present study describes the characteristics of three nuclear photosynthesis mutants in maize. Two of these mutants, hcf*-33 and hcf*-19G, are fully blocked in PSII, whereas a third mutant, hcf*-19YG, is partially blocked in PSII. All three mutations affect not only PSII activity, but also cause the loss of one or both redox

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“…The fluorescence spectrum of a greening maize leaf at 5 K ( fig.l, curve 1) is very similar to the one of intact chloroplasts [8], showing that both photosystems and their antennas are fully developed. The 736 nm fluorescence band arises mainly from the antenna connected with PSI although at 700 < A < 735 nm the fluorescence intensity of PS II [16] and light-harvesting Chl a/b protein [17] is also significant.…”

Section: Resultsmentioning

confidence: 69%

“…Such red-shifts are ascribed to pigment-pigment [1][2][3][4] or pigment-protein [5] interactions, which have been substantiated by theoretical [3,4] and experimental [1,2,4] studies of various model systems. In spite of numerous spectroscopic investigations of intact samples and chlorophyll-protein particles [6][7][8][9][10], many important questions are still of current interest, e.g. those concerning the positions of electronic and Correspondence address: K. Mauring, Institute of Physics, Estonian SSR Academy of Sciences, 202400 Tartu, Riia 142, USSR vibronic levels of pigments in vivo, the heterogeneity of spectral bands, the strength of vibronic and electron-phonon coupling, etc.…”

Section: Introductionmentioning

confidence: 99%

A spectral hole‐burning study of long‐wavelength chlorophyll a forms in greening leaves at 5 K

1987

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Persistent holes have been burnt in the spectra of post-etiolated maize leaves in the spectral interval 700-745 nm at 5 K. Narrow (< 1 era -x) holes detectable both in fluorescence and excitation spectra correspond to the zero-phonon purely electronic SFS0 transition of chlorophyll a rather than to the S~-S0 vibronic or Sn~S0 higher singlet transitions. The spectral composition of the inhomogeneously broadened absorption and fluorescence contours of long-wavelength chlorophyll a forms in plants is discussed in terms of the contributions of phonon-wings, vibronic satellites, purely electronic Sl-S0 transitions and its higher excitonic components.Long-wavelength chlorophyll a form; Low-temperature spectroscopy; Spectral hole burning; Zero-phonon transition;( Zea mays )

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Fluorescence emission spectra of chloroplasts and subchloroplast preparations at low temperature

Cited by 103 publications

References 31 publications

Protection and storage of chlorophyll in overwintering evergreens

Protection and storage of chlorophyll in overwintering evergreens

Characterization of Three Photosystem II Mutants in Zea mays L. Lacking a 32,000 Dalton Lamellar Polypeptide

A spectral hole‐burning study of long‐wavelength chlorophyll a forms in greening leaves at 5 K

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