Form I Rubiscos from non‐green algae are expressed abundantly but not assembled in tobacco chloroplasts

Form I Rubiscos from non‐green algae are expressed abundantly but not assembled in tobacco... Non‐green algae have Rubiscos that are phylogenetically distinct from their counterparts in green algae and higher plants. Some non‐green‐algal Rubiscos are more specific for CO2, relative to O2, than higher‐plant Rubiscos, sometimes coupled with lower Michaelis constants for CO2. If these Rubiscos could be substituted for the higher‐plant enzyme, and if they functioned successfully in the higher‐plant chloroplast and were regulated appropriately, they would improve the CO2 use and quantum efficiency of higher‐plant photosynthesis. To assess the feasibility of expressing non‐green algal Rubiscos in higher‐plant chloroplasts, we inserted the rbcLS operons from the rhodophyte Galdieria sulphuraria and the diatom Phaeodactylum tricornutum into the inverted repeats of the plastid genome of tobacco, leaving the tobacco rbcL gene unaltered. Homoplasmic transformants were selected. The transgenes directed the synthesis of abundant amounts of transcripts and both subunits of the foreign Rubiscos. In some circumstances, leaves of the transformants with the P. tricornutum Rubisco contained as much foreign Rubisco protein as endogenous tobacco Rubisco (>30% of the soluble leaf protein). However, the subunits of the foreign Rubiscos were not properly folded and/or assembled. All the foreign large subunits and most of the foreign small subunits were recovered in the insoluble fractions of leaf extracts. Edman sequencing yielded the expected N‐terminal sequences for the foreign small subunits but the N‐termini of the foreign large subunits were blocked. Accumulation of large amounts of denatured foreign Rubisco in the leaves, particularly of the P. tricornutum transformants, caused a reduction in the amount of tobacco Rubisco present, with concomitant reductions in leaf CO2 assimilation and plant growth. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Plant Journal Wiley

Form I Rubiscos from non‐green algae are expressed abundantly but not assembled in tobacco chloroplasts

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Abstract

Non‐green algae have Rubiscos that are phylogenetically distinct from their counterparts in green algae and higher plants. Some non‐green‐algal Rubiscos are more specific for CO2, relative to O2, than higher‐plant Rubiscos, sometimes coupled with lower Michaelis constants for CO2. If these Rubiscos could be substituted for the higher‐plant enzyme, and if they functioned successfully in the higher‐plant chloroplast and were regulated appropriately, they would improve the CO2 use and quantum efficiency of higher‐plant photosynthesis. To assess the feasibility of expressing non‐green algal Rubiscos in higher‐plant chloroplasts, we inserted the rbcLS operons from the rhodophyte Galdieria sulphuraria and the diatom Phaeodactylum tricornutum into the inverted repeats of the plastid genome of tobacco, leaving the tobacco rbcL gene unaltered. Homoplasmic transformants were selected. The transgenes directed the synthesis of abundant amounts of transcripts and both subunits of the foreign Rubiscos. In some circumstances, leaves of the transformants with the P. tricornutum Rubisco contained as much foreign Rubisco protein as endogenous tobacco Rubisco (>30% of the soluble leaf protein). However, the subunits of the foreign Rubiscos were not properly folded and/or assembled. All the foreign large subunits and most of the foreign small subunits were recovered in the insoluble fractions of leaf extracts. Edman sequencing yielded the expected N‐terminal sequences for the foreign small subunits but the N‐termini of the foreign large subunits were blocked. Accumulation of large amounts of denatured foreign Rubisco in the leaves, particularly of the P. tricornutum transformants, caused a reduction in the amount of tobacco Rubisco present, with concomitant reductions in leaf CO2 assimilation and plant growth.

Journal

The Plant JournalWiley

Published: Jun 1, 2001

Keywords: ; ; ; ; ;

References

  • Studies with Cyanidium caldarium, an anomalously pigmented chlorophyte
    Allen, M.B.
  • Introduction to the Algae.
    Bold, H.C.; Wynne, M.J.
  • The CO2/O2 specificity of ribulose 1,5‐bisphosphate carboxylase/oxygenase – depend ence on ribulosebisphosphate concentration, pH and temperature
    Jordan, D.B.; Ogren, W.L.
  • Regulation of soybean net photosynthetic CO2 fixation by the interaction of CO2, O2, and ribulose 1,5‐bisphosphate carboxylase
    Laing, W.A.; Ogren, W.L.; Hageman, R.H.
  • Determination of accurate coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents: Verification of the chlorophyll standards by atomic absorption spectroscopy
    Porra, R.J.; Thompson, W.A.; Kriedemann, P.E.
  • Photosynthesis: Physiology and Metabolism
    Roy, H.; Andrews, T.J.
  • High‐yield production of a human therapeutic protein in tobacco chloroplasts
    Staub, J.M.; Garcia, B.; Graves, J.
  • Microbial ribulose 1,5‐bisphosphate carboxylase/oxygenase: a different perspective
    Tabita, F.R.
  • Ribulose‐1,5‐bisphosphate carboxylase/oxygenase from thermophilic red algae with a strong specificity for CO2 fixation
    Uemura, K.; Anwaruzzaman; Miyachi, S.; Yokota, A.

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