Photosynthesis and Light Activation of Ribulose 1,5-bisphosphate Carboxylase in the Presence of Starch

In our previous research, we showed that low Cd concentration increases the effectiveness of the processes leading to activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). This stimulation was dependent on carbonic anhydrase (CA) activity and resulted in protecting Rubisco activity against Cd toxicity. The aim of the present paper was to test whether this mechanism has any influence on light activation of photosynthesis during the first 2 h of illumination. Both the “activation mechanism” of plant response to Cd-stress conditions and its full efficiency at low Cd concentration were confirmed. The CA-dependent light activation of Rubisco at low Cd level was correlated with accelerated attaining of the maximum Rubisco activity by these plants. The amount of Rubisco was also Cd- and timedependent and varied from continuous accumulation in control plants till reaching the maximum level within 30 minutes for the high Cd concentration. An increase in CA activity that was found to be parallel to the decrease of the amount of CA suggested activation of the enzyme by low Cd concentration

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Reversible Light-Activation of Ribulose Bisphosphate Carboxylase/Oxygenase in Isolated Barley Protoplasts and Chloroplasts

PLANT PHYSIOLOGY ◽

10.1104/pp.70.2.366 ◽

1982 ◽

Vol 70 (2) ◽

pp. 366-369 ◽

Cited By ~ 12

Author(s):

Richard C. Sicher

Keyword(s):

Ribulose Bisphosphate Carboxylase ◽

Light Activation ◽

Ribulose Bisphosphate ◽

Bisphosphate Carboxylase ◽

Ribulose Bisphosphate Carboxylase Oxygenase

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Involvement of Stromal ATP in the Light Activation of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase in Intact Isolated Chloroplasts

PLANT PHYSIOLOGY ◽

10.1104/pp.86.1.293 ◽

1988 ◽

Vol 86 (1) ◽

pp. 293-298 ◽

Cited By ~ 41

Author(s):

Simon P. Robinson ◽

Archie R. Portis

Keyword(s):

Light Activation ◽

Bisphosphate Carboxylase ◽

Isolated Chloroplasts

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Three-dimensional distribution of ribulose-1, 5-bisphosphate carboxylase/oxygemase during the early development of proplastids in dark-grown Euglena cells transferred to an inorganic medium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100162090 ◽

1990 ◽

Vol 48 (3) ◽

pp. 906-907

Author(s):

Tomoko Ehara ◽

Shuji Sumida ◽

Tetsuaki Osafune ◽

Eiji Hase

Keyword(s):

Cell Suspension ◽

Euglena Gracilis ◽

Carbon Materials ◽

Three Dimensional ◽

Peripheral Region ◽

Plastid Development ◽

Bisphosphate Carboxylase ◽

Inorganic Medium ◽

Ribulose 1 ◽

Dimensional Distribution

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.

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