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Titolo:
Form I Rubiscos from non-green algae are expressed abundantly but not assembled in tobacco chloroplasts
Autore:
Whitney, SM; Baldett, P; Hudson, GS; Andrews, TJ;
Indirizzi:
Australian Natl Univ, Res Sch Biol Sci, Canberra, ACT 2601, Australia Australian Natl Univ Canberra ACT Australia 2601 rra, ACT 2601, Australia
Titolo Testata:
PLANT JOURNAL
fascicolo: 5, volume: 26, anno: 2001,
pagine: 535 - 547
SICI:
0960-7412(200106)26:5<535:FIRFNA>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
RIBULOSE 1,5-BISPHOSPHATE CARBOXYLASE; BISPHOSPHATE CARBOXYLASE; RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE/OXYGENASE; CRYSTAL-STRUCTURE; LARGE SUBUNIT; CYANIDIUM-CALDARIUM; CO2/O2 SPECIFICITY; TRANSGENIC TOBACCO; MOLECULAR-BIOLOGY; SPECIES VARIATION;
Keywords:
Rubisco; chloroplast; transformation; protein; assembly; folding;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
47
Recensione:
Indirizzi per estratti:
Indirizzo: Andrews, TJ Australian Natl Univ, Res Sch Biol Sci, POB 475, Canberra, ACT2601, Australia Australian Natl Univ POB 475 Canberra ACT Australia 2601 ralia
Citazione:
S.M. Whitney et al., "Form I Rubiscos from non-green algae are expressed abundantly but not assembled in tobacco chloroplasts", PLANT J, 26(5), 2001, pp. 535-547

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 O-2, 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.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/04/20 alle ore 09:40:11