The Development of Chlorophyll and Oxygen-evolving Power in Etiolated Barley Leaves When Illuminated.

Smith, James H. C.

doi:10.1104/pp.29.2.143

Cited by 71 publications

(20 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, our rates of oxygen evolution at 90 to 150 min of greening were considerably higher than those reported by Smith (35). In fact, the average photosynthetic rate per unit area of leaf was as high at 2 hr as at the later stages of greening, suggesting that there were only small variations in the number of functional photosynthetic units per unit area between 2 hr and 24 hr of greening.…”

Section: Discussioncontrasting

confidence: 52%

“…Smith (35), using a very sensitive assay, reported oxygen evolution from etiolated barley leaves after 30 min of illumination, although the rate of evolution, even at 100 min of greening was very low compared with that observed in a green leaf. Etiolated maize leaves showed some oxygen evolution after 2.25 hr of illumination (23), greening rice seedlings at 2 hr (28), and wheat seedlings at 2 to 3 hr (25).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Development of Photochemical Activity and the Appearance of the High Potential Form of Cytochrome b-559 in Greening Barley Seedlings

Henningsen¹,

Boardman²

1973

Plant Physiol.

124

View full text Add to dashboard Cite

The development of photochemical activity during the greening of dark-grown barley seedlings (Hordeum vulgare L. cv. Svalofs Bonus) was studied in relation to the formation of the high potential form of cytochrome b-559 (cytochrome b-559HP). Photosynthetie oxygen evolution from leaves was detected at 30 minutes of illumination. The rate of oxygen evolution per gram fresh weight of leaf was as high at 2 to 2.5 hours of greening as at 24 hours or in fully greened leaves. On a chlorophyll basis, the photosynthetic rate at 90 minutes of greening was 80-fold greater than the rate at 45 hours. It is concluded that the majority of photosynthetic units are functional at an early stage of greening, and that chlorophyll synthesis during greening serves to increase the size of the units.Plastids showed substantial photochemical oxygen evolution after a seedling greening time of 1 hour. However, a comparison of the relative activity of leaves and plastids at 2 hours and 24 hours of greening suggests that there was some inactivation of greening plastids during isolation. Appreciable photosystem I activity was observed as early as 15 minutes of greening.The synthesis of cytochrome b-5591p during greening does not correlate with the onset of oxygen evolution. Cytochrome b-559HP was absent from etioplasts and in most preparations of 2-hour plastids. The average amount of cytochrome b-559HP at 2 hours of greening was well below the level needed to provide 1 molecule of the carrier for each functional photosynthetic chain. The results suggest that cytochrome b-559Hp is not essential for oxygen evolution. Cytochrome t, cytochrome be, and the low potential forn of cytochrome b-559 were present in the etioplast. There was little increase in the levels of these cytochromes during 24 hours of greening.In a previous study (5), it was shown that cytochrome f and cytochrome b6, which are components of photosystem I (7), are present in the plastids of dark-grown bean leaves, but cytochrome b-559, a component of photosystem II, is absent. Cytochrome b-559 was detectable after 6 hr of greening. It increased gradually 1 Permanent address: Institute of Genetics, University of Copenhagen, Denmark. on further illumination of the seedlings, but even at 16 hr, the amount of cytochrome b-559 relative to cytcchrome f and cytochrome b6 was well below that of mature chloroplasts. Bendall (2) demonstrated that the absorption band attributed to cytochrome b6 in the earlier work with chloroplasts (7) and etioplasts (5) was due to the presence of two dithionite-reducible cytochromes with a-bands at 563 to 564 nm (cytochrome bQ) and 559 nm (cytochrome b-559Lp), respectively. Plesnicar and Bendall (32) confirmed the observation of Boardman (5) that the high potential form of cytochrome b-559 (cytochrome b-559HP) is absent from etioplasts. In the present work, we have studied the appearance of cytochrome b-559HP in plastids from greening barley seedlings in relation to the onset of oxygen evolution in the leaves and in isolated plastids, and on the ...

show abstract

Section: Discussioncontrasting

confidence: 52%

mentioning

confidence: 99%

Development of Photochemical Activity and the Appearance of the High Potential Form of Cytochrome b-559 in Greening Barley Seedlings

Henningsen¹,

Boardman²

1973

Plant Physiol.

124

View full text Add to dashboard Cite

show abstract

“…Smith (29) worked with etiolated barley leaves studying the development of chlorophyll and oxygen-evolving power, and observed that chlorophyll b was not necessary for oxygen evolution. Highkin and Frenkel (13) Analyses.…”

mentioning

confidence: 99%

The Photosynthetic Response to a Shift in the Chlorophyll a to Chlorophyll b Ratio of Chlorella

Reger

Krauss

1970

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…In comparable experiments, but with somewhat older leaves. Smith (1954) has also demonstrated a relatively short lag in the production of oxygen by photosynthesis when the etiolated leaves were exposed to light.…”

Section: Discussionmentioning

confidence: 99%

The Development of Chloroplasts and Photosynthetic Activities in Young Barley Leaves

Rhodes

Yemm

1966

New Phytologist

View full text Add to dashboard Cite

SUMMARYCarbon dioxide exchanges in the dark and in the light indicate that photosynthetic activity occurs m young leaves of barley seedlings after about 3 hours illumination under favourable conditions. Activity increases rapidly as chlorophyll is formed in the expanding leaf blade; a compensation point is reached after 30-40 hours and thereafter carbon dioxide assimilation exceeds respiration.Changes in the fine structure of plastids in the young leaves were examined by electron microscopy; some of the chief stages in the development of the lamella system and the diflFerentiation of grana are described. The presence of ribosome-and nucleoplasm-like structures in the chloroplast stroma was indicated.The relationship between the development of chloroplasts and their photosynthetic activity is discussed. It is suggested that the formation of distinctive double membranes between the thylakoids of the grana plays an important part in the structural organization of the pigment system. The action of light on chloroplast development indicates that a primary step in photomorphogenesis is the conversion of protochlorophyllide to chlorophyll. The further extension and development of the lamellar system probably depends upon the biosynthesis of proteins and lipids, closely linked with photosynthesis and operating under the control of nucleic acids.

show abstract

The Development of Chlorophyll and Oxygen-evolving Power in Etiolated Barley Leaves When Illuminated.

Cited by 71 publications

References 12 publications

Development of Photochemical Activity and the Appearance of the High Potential Form of Cytochrome b-559 in Greening Barley Seedlings

Development of Photochemical Activity and the Appearance of the High Potential Form of Cytochrome b-559 in Greening Barley Seedlings

The Photosynthetic Response to a Shift in the Chlorophyll a to Chlorophyll b Ratio of Chlorella

The Development of Chloroplasts and Photosynthetic Activities in Young Barley Leaves

Contact Info

Product

Resources

About