ACCLIMATION OF SYNECHOCOCCUS STRAIN WH7803 TO AMBIENT CO2 CONCENTRATION AND TO ELEVATED LIGHT INTENSITY1

Hassidim, Miriam; Keren, Nir; Ohad, Itzhak; Reinhold, Leonora

doi:10.1111/j.0022-3646.1997.00811.x

Cited by 35 publications

(26 citation statements)

References 35 publications

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“…Synechococcus spp. WH7803; Hassidim et al, 1997). In contrast, other a-cyanobacteria, including transition strains, do not appear to show induction of CCM physiology, such as Synechococcus spp.…”

Section: Induction Of Enhanced Ccm Physiology At Low Comentioning

confidence: 99%

Comparing the in Vivo Function of α-Carboxysomes and β-Carboxysomes in Two Model Cyanobacteria

et al. 2014

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The carbon dioxide (CO 2 )-concentrating mechanism of cyanobacteria is characterized by the occurrence of Rubisco-containing microcompartments called carboxysomes within cells. The encapsulation of Rubisco allows for high-CO 2 concentrations at the site of fixation, providing an advantage in low-CO 2 environments. Cyanobacteria with Form-IA Rubisco contain a-carboxysomes, and cyanobacteria with Form-IB Rubisco contain b-carboxysomes. The two carboxysome types have arisen through convergent evolution, and a-cyanobacteria and b-cyanobacteria occupy different ecological niches. Here, we present, to our knowledge, the first direct comparison of the carboxysome function from a-cyanobacteria (Cyanobium spp. PCC7001) and b-cyanobacteria (Synechococcus spp. PCC7942) with similar inorganic carbon (C i ; as CO 2 and HCO 32 ) transporter systems. Despite evolutionary and structural differences between a-carboxysomes and b-carboxysomes, we found that the two strains are remarkably similar in many physiological parameters, particularly the response of photosynthesis to light and external C i and their modulation of internal ribulose-1,5-bisphosphate, phosphoglycerate, and C i pools when grown under comparable conditions. In addition, the different Rubisco forms present in each carboxysome had almost identical kinetic parameters. The conclusions indicate that the possession of different carboxysome types does not significantly influence the physiological function of these species and that similar carboxysome function may be possessed by each carboxysome type. Interestingly, both carboxysome types showed a response to cytosolic C i , which is of higher affinity than predicted by current models, being saturated by 5 to 15 mM C i . This finding has bearing on the viability of transplanting functional carboxysomes into the C 3 chloroplast.

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Section: Induction Of Enhanced Ccm Physiology At Low Comentioning

confidence: 99%

Comparing the in Vivo Function of α-Carboxysomes and β-Carboxysomes in Two Model Cyanobacteria

et al. 2014

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“…Short-term acclimation includes state transitions, protective energy dissipation (Campbell et al, 1998;Niyogi, 1999), changes in the efficiency of energy transfer from the harvesting complex to photosystem II (PSII; Hassidim et al, 1997), and the formation of nonfunctional PSII reaction centers (Chow, 1994;Anderson et al, 1997). These responses occur rather rapidly and usually are completed within several minutes.…”

Section: Introductionmentioning

confidence: 99%

DNA Microarray Analysis of Cyanobacterial Gene Expression during Acclimation to High Light

et al. 2001

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DNA microarrays bearing nearly all of the genes of the unicellular cyanobacterium Synechocystis sp PCC 6803 were used to examine the temporal program of gene expression during acclimation from low to high light intensity. A complete pattern is provided of gene expression during acclimation of a photosynthetic organism to changing light intensity. More than 160 responsive genes were identified and classified into distinct sets. Genes involved in light absorption and photochemical reactions were downregulated within 15 min of exposure to high light intensity, whereas those associated with CO 2 fixation and protection from photoinhibition were upregulated. Changes in the expression of genes involved in replication, transcription, and translation, which were induced to support cellular proliferation, occurred later. Several unidentified open reading frames were induced or repressed. The possible involvement of these genes in the acclimation to high light conditions is discussed. INTRODUCTIONPhotosynthetic organisms must acclimate to changing light intensity in their environment. The acclimation process includes changes in the photosynthetic apparatus, presumably to balance energy input and consumption (Boardman, 1977). If energy supply (light harvesting and electron transport) exceeds its dissipation (by CO 2 fixation and other energy-demanding processes), particularly under high light (HL) conditions, the photosynthetic electron transport components could become relatively reduced. This may result in excess production of reactive oxygen species (ROS) leading to severe damage to many cellular processes (Asada, 1994). Absorption of excess light energy therefore must be avoided by reduction of both antenna size and photosystem content. Furthermore, under HL conditions the capacity for CO 2 fixation increases (Björkman, 1981;Anderson, 1986) and protection from ROS is enhanced (Grace and Logan, 1996).Acclimation from low light (LL) to HL conditions can be divided into short-term and long-term processes (Anderson, 1986;Anderson et al., 1995). Short-term acclimation includes state transitions, protective energy dissipation (Campbell et al., 1998;Niyogi, 1999), changes in the efficiency of energy transfer from the harvesting complex to photosystem II (PSII; Hassidim et al., 1997), and the formation of nonfunctional PSII reaction centers (Chow, 1994;Anderson et al., 1997). These responses occur rather rapidly and usually are completed within several minutes. Conversely, the long-term acclimation to HL is much slower because it involves changes in the composition, function, and structure of the photosynthetic apparatus as well as other photosynthesis-related components. Completion of the long-term processes may take hours or even days.Physiological responses to changing light intensity have been examined extensively Gibson, 1982a, 1982b;Anderson, 1986;Neale and Melis, 1986), and some of the relevant molecular mechanisms have been described (Anderson et al., 1995;Hihara, 1999;Niyogi, 1999). Nevertheless, the mechanisms that ...

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“…A related study (27) found that low-CO 2 adapted cells of Synechococcus WH7803 have a good uptake affinity for Ci (K 0.5 of 13 M) and showed rates of photosynthesis up to 70 mol O 2 ⅐mg Chl Ϫ1 ⅐h Ϫ1 . Synechococcus WH8102 possesses genes for lowaffinity CO 2 uptake (7) and BicA-type HCO 3 Ϫ uptake (this study), but lacks genes for high-affinity CO 2 uptake and SbtAtype HCO 3 Ϫ uptake (7).…”

mentioning

confidence: 96%

Identification of a SulP-type bicarbonate transporter in marine cyanobacteria

Price

Woodger

Badger

et al. 2004

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

280

276

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Cyanobacteria possess a highly effective CO2-concentrating mechanism that elevates CO 2 concentrations around the primary carboxylase, Rubisco (ribulose-1,5-bisphosphate carboxylase͞oxy-genase). This CO 2-concentrating mechanism incorporates lightdependent, active uptake systems for CO 2 and HCO 3 ؊ . Through mutant studies in a coastal marine cyanobacterium, Synechococcus sp. strain PCC7002, we identified bicA as a gene that encodes a class of HCO 3 ؊ transporter with relatively low transport affinity, but high flux rate. BicA is widely represented in genomes of oceanic cyanobacteria and belongs to a large family of eukaryotic and prokaryotic transporters presently annotated as sulfate transporters or permeases in many bacteria (SulP family). Further gain-offunction experiments in the freshwater cyanobacterium Synechococcus PCC7942 revealed that bicA expression alone is sufficient to confer a Na ؉ -dependent, HCO 3 ؊ uptake activity. We identified and characterized three cyanobacterial BicA transporters in this manner, including one from the ecologically important oceanic strain, Synechococcus WH8102. This study presents functional data concerning prokaryotic members of the SulP transporter family and represents a previously uncharacterized transport function for the family. The discovery of BicA has significant implications for understanding the important contribution of oceanic strains of cyanobacteria to global CO 2 sequestration processes.SulP transporters ͉ CO2 sequestration ͉ photosynthesis I t is estimated that some 50% of global primary productivity occurs in the oceans, and marine cyanobacteria contribute significantly to this global CO 2 sequestration process (1). For example, in open oceans located between 40°N and 40°S, photosynthetic CO 2 fixation is dominated by marine cyanobacteria of the Synechococcus and Prochlorococcus genera, and together these species perform 30-80% of primary production (2, 3). The largest nutrient uptake flux encountered by marine cyanobacteria is for dissolved inorganic carbon (Ci), yet relatively little is known about the process of Ci accumulation for photosynthesis in the oceanic cyanobacteria, in contrast to our knowledge of freshwater strains.In aquatic systems, Ci exists mainly as two slowly interconvertible forms, CO 2 and HCO 3 Ϫ . In response to unique restrictions on the rate of CO 2 supply in the aquatic environment, cyanobacteria have evolved a very efficient mechanism for capturing CO 2 and HCO 3 Ϫ for photosynthetic fixation into sugars. The Ci-capturing mechanism functions as a CO 2 -concentrating mechanism because it effectively concentrates CO 2 around the main CO 2 -fixing enzyme, ribulose-1,5-bisphosphate carboxylase͞oxygenase (Rubisco). In the best characterized species, mostly freshwater cyanobacterial strains, the CO 2 -concentrating mechanism consists of several active uptake systems for CO 2 and HCO 3 Ϫ , plus a unique microcompartment called the carboxysome that contains the CO 2 -fixing enzyme, Rubisco (4-6).In recent years, the availability of a...

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ACCLIMATION OF SYNECHOCOCCUS STRAIN WH7803 TO AMBIENT CO₂ CONCENTRATION AND TO ELEVATED LIGHT INTENSITY¹

Cited by 35 publications

References 35 publications

Comparing the in Vivo Function of α-Carboxysomes and β-Carboxysomes in Two Model Cyanobacteria

Comparing the in Vivo Function of α-Carboxysomes and β-Carboxysomes in Two Model Cyanobacteria

DNA Microarray Analysis of Cyanobacterial Gene Expression during Acclimation to High Light

Identification of a SulP-type bicarbonate transporter in marine cyanobacteria

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