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Occurrence of Far-Red Light Photoacclimation (FaRLiP) in Diverse Cyanobacteria.

Gan F, Shen G, Bryant DA - Life (Basel) (2014)

Bottom Line: Leptolyngbya sp.JSC-1.We conclude that these photosynthetic gene clusters are diagnostic of the capacity to photoacclimate to and grow in far-red light.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA. fxg142@psu.edu.

ABSTRACT
Cyanobacteria have evolved a number of acclimation strategies to sense and respond to changing nutrient and light conditions. Leptolyngbya sp. JSC-1 was recently shown to photoacclimate to far-red light by extensively remodeling its photosystem (PS) I, PS II and phycobilisome complexes, thereby gaining the ability to grow in far-red light. A 21-gene photosynthetic gene cluster (rfpA/B/C, apcA2/B2/D2/E2/D3, psbA3/D3/C2/B2/ H2/A4, psaA2/B2/L2/I2/F2/J2) that is specifically expressed in far-red light encodes the core subunits of the three major photosynthetic complexes. The growth responses to far-red light were studied here for five additional cyanobacterial strains, each of which has a gene cluster similar to that in Leptolyngbya sp. JSC-1. After acclimation all five strains could grow continuously in far-red light. Under these growth conditions each strain synthesizes chlorophylls d, f and a after photoacclimation, and each strain produces modified forms of PS I, PS II (and phycobiliproteins) that absorb light between 700 and 800 nm. We conclude that these photosynthetic gene clusters are diagnostic of the capacity to photoacclimate to and grow in far-red light. Given the diversity of terrestrial environments from which these cyanobacteria were isolated, it is likely that FaRLiP plays an important role in optimizing photosynthesis in terrestrial environments.

No MeSH data available.


Related in: MedlinePlus

In-line absorption spectra for Chl f and Chl d from five cyanobacterial strains grown in far-red light (FRL). (A) Absorption spectra of Chl f; (B) Absorption spectra of Chl d. Chls were extracted from cells of Synechococcus sp. PCC 7335 (7335), Chr. thermalis PCC 7203 (7203), Calothrix sp. PCC 7507 (7507), F. thermalis PCC 7521 (7521), and Chlorogloeopsis sp. PCC 9212 (9212), which had been grown in FRL.
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life-05-00004-f005: In-line absorption spectra for Chl f and Chl d from five cyanobacterial strains grown in far-red light (FRL). (A) Absorption spectra of Chl f; (B) Absorption spectra of Chl d. Chls were extracted from cells of Synechococcus sp. PCC 7335 (7335), Chr. thermalis PCC 7203 (7203), Calothrix sp. PCC 7507 (7507), F. thermalis PCC 7521 (7521), and Chlorogloeopsis sp. PCC 9212 (9212), which had been grown in FRL.

Mentions: Reversed-phase HPLC analyses were conducted to identify pigments extracted from cells of Synechococcus sp. PCC 7335, F. thermalis PCC 7521, Calothrix sp. PCC 7507, Chlorogloeopsis sp. PCC 9212, and C. thermalis PCC 7203 that had been grown in WL (or 645-nm RL for Synechococcus sp. PCC 7335) and FRL. As shown in Figure 4, only Chl a was detected in cells grown in WL (or RL). However, two additional peaks that eluted earlier than Chl a (at 43 min) were detected in the HPLC profiles of the Chls extracted from cells grown in FRL. The elution times (37 and 38 min) for these minor Chls exactly matched those of Chl d and Chl f, respectively, which had previously been identified and verified by mass spectrometry for Leptolyngbya JSC-1 [28]. As confirmed by the in-line absorption spectra (Figure 5), the Qy absorption maximum of Chl f occurred at 706 nm and the Soret maxima were observed at 405 nm and 445 nm (Figure 5A) [28,33]. The in-line absorption spectrum of Chl d exhibited a Qy absorption maximum at 695 nm and had Soret absorption maxima at 401 nm and 455 nm (Figure 5B) [28,33]. The amounts of Chl d and f seemed to vary somewhat under the growth conditions employed. Chl d was estimated to be ~1% to 2% of the total Chl, and Chl f accounted for about 5% to 10% of the total Chl produced by these strains. These results establish that the biosynthesis of Chl f and Chl d is probably a property shared by all cyanobacteria that perform FaRLiP.


Occurrence of Far-Red Light Photoacclimation (FaRLiP) in Diverse Cyanobacteria.

Gan F, Shen G, Bryant DA - Life (Basel) (2014)

In-line absorption spectra for Chl f and Chl d from five cyanobacterial strains grown in far-red light (FRL). (A) Absorption spectra of Chl f; (B) Absorption spectra of Chl d. Chls were extracted from cells of Synechococcus sp. PCC 7335 (7335), Chr. thermalis PCC 7203 (7203), Calothrix sp. PCC 7507 (7507), F. thermalis PCC 7521 (7521), and Chlorogloeopsis sp. PCC 9212 (9212), which had been grown in FRL.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390838&req=5

life-05-00004-f005: In-line absorption spectra for Chl f and Chl d from five cyanobacterial strains grown in far-red light (FRL). (A) Absorption spectra of Chl f; (B) Absorption spectra of Chl d. Chls were extracted from cells of Synechococcus sp. PCC 7335 (7335), Chr. thermalis PCC 7203 (7203), Calothrix sp. PCC 7507 (7507), F. thermalis PCC 7521 (7521), and Chlorogloeopsis sp. PCC 9212 (9212), which had been grown in FRL.
Mentions: Reversed-phase HPLC analyses were conducted to identify pigments extracted from cells of Synechococcus sp. PCC 7335, F. thermalis PCC 7521, Calothrix sp. PCC 7507, Chlorogloeopsis sp. PCC 9212, and C. thermalis PCC 7203 that had been grown in WL (or 645-nm RL for Synechococcus sp. PCC 7335) and FRL. As shown in Figure 4, only Chl a was detected in cells grown in WL (or RL). However, two additional peaks that eluted earlier than Chl a (at 43 min) were detected in the HPLC profiles of the Chls extracted from cells grown in FRL. The elution times (37 and 38 min) for these minor Chls exactly matched those of Chl d and Chl f, respectively, which had previously been identified and verified by mass spectrometry for Leptolyngbya JSC-1 [28]. As confirmed by the in-line absorption spectra (Figure 5), the Qy absorption maximum of Chl f occurred at 706 nm and the Soret maxima were observed at 405 nm and 445 nm (Figure 5A) [28,33]. The in-line absorption spectrum of Chl d exhibited a Qy absorption maximum at 695 nm and had Soret absorption maxima at 401 nm and 455 nm (Figure 5B) [28,33]. The amounts of Chl d and f seemed to vary somewhat under the growth conditions employed. Chl d was estimated to be ~1% to 2% of the total Chl, and Chl f accounted for about 5% to 10% of the total Chl produced by these strains. These results establish that the biosynthesis of Chl f and Chl d is probably a property shared by all cyanobacteria that perform FaRLiP.

Bottom Line: Leptolyngbya sp.JSC-1.We conclude that these photosynthetic gene clusters are diagnostic of the capacity to photoacclimate to and grow in far-red light.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA. fxg142@psu.edu.

ABSTRACT
Cyanobacteria have evolved a number of acclimation strategies to sense and respond to changing nutrient and light conditions. Leptolyngbya sp. JSC-1 was recently shown to photoacclimate to far-red light by extensively remodeling its photosystem (PS) I, PS II and phycobilisome complexes, thereby gaining the ability to grow in far-red light. A 21-gene photosynthetic gene cluster (rfpA/B/C, apcA2/B2/D2/E2/D3, psbA3/D3/C2/B2/ H2/A4, psaA2/B2/L2/I2/F2/J2) that is specifically expressed in far-red light encodes the core subunits of the three major photosynthetic complexes. The growth responses to far-red light were studied here for five additional cyanobacterial strains, each of which has a gene cluster similar to that in Leptolyngbya sp. JSC-1. After acclimation all five strains could grow continuously in far-red light. Under these growth conditions each strain synthesizes chlorophylls d, f and a after photoacclimation, and each strain produces modified forms of PS I, PS II (and phycobiliproteins) that absorb light between 700 and 800 nm. We conclude that these photosynthetic gene clusters are diagnostic of the capacity to photoacclimate to and grow in far-red light. Given the diversity of terrestrial environments from which these cyanobacteria were isolated, it is likely that FaRLiP plays an important role in optimizing photosynthesis in terrestrial environments.

No MeSH data available.


Related in: MedlinePlus