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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

Absorption spectra (A) and low-temperature (77 K) fluorescence emission spectra (B) for Synechococcus sp. PCC 7335 cells grown in white light (WL, solid black line), red light (RL, solid red line), far-red light (FRL, solid blue line), and FRL with 1 mM fructose added to the growth medium (dotted blue line). The excitation wavelength was 440 nm for the fluorescence emission spectra in panel B.
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life-05-00004-f002: Absorption spectra (A) and low-temperature (77 K) fluorescence emission spectra (B) for Synechococcus sp. PCC 7335 cells grown in white light (WL, solid black line), red light (RL, solid red line), far-red light (FRL, solid blue line), and FRL with 1 mM fructose added to the growth medium (dotted blue line). The excitation wavelength was 440 nm for the fluorescence emission spectra in panel B.

Mentions: Like Leptolyngbya JSC-1, Synechococcus sp. PCC 7335 is a phycoerythrin-producing strain that is known to perform type-III CCA [31,32]. To determine whether this marine cyanobacterium could also perform FaRLiP, cells were grown under different light conditions. Figure 2A shows whole-cell absorption spectra for Synechococcus sp. PCC 7335 cells that had been grown in WL, 645-nm RL, and 720-nm FRL (±1 mM fructose). The absorption spectrum of whole cells grown in WL had much higher absorption at ~569 nm due to phycoerythrin and much less absorption at 625 nm compared to cells grown in 645-nm RL. These cells were brown and blue-green in color, respectively, which is consistent with previous studies that have shown that Synechococcus sp. PCC 7335 is capable of Type-III CCA [31,32]. Cells grown in 720-nm FRL, with or without 1 mM fructose present, had very similar absorption spectra (Figure 2A). The blue-green colored cells exhibited an absorption feature extending from 700 nm to 800 nm with a maximum at ~707 nm that was not observed for cells grown under WL and 645-nm RL conditions. Figure 2B shows the low-temperature fluorescence emission spectra of the same Synechococcus sp. PCC 7335 cells. Cells grown in WL and 645-nm RL had nearly identical fluorescence emission spectra, which exhibited maxima at 683 and 695 nm for PS II and 724 nm for PS I. Cells grown in 720-nm FRL (± 1 mM fructose) had a very sharp and intense fluorescence emission maximum at 738 nm with lesser maxima at 716 nm and 683 nm and rather minimal emission at 695 nm. These fluorescence emission properties are similar to those Leptolyngbya JSC-1 cells producing Chl d and Chl f, except that the major Chl emission peak is blue-shifted about 10 nm [28]. These absorption and fluorescence emission results indicate that Synechococcus sp. PCC 7335 synthesizes different pigments and/or assembles different photosynthetic complexes with absorption beyond 700 nm when cells are grown in FRL.


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

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

Absorption spectra (A) and low-temperature (77 K) fluorescence emission spectra (B) for Synechococcus sp. PCC 7335 cells grown in white light (WL, solid black line), red light (RL, solid red line), far-red light (FRL, solid blue line), and FRL with 1 mM fructose added to the growth medium (dotted blue line). The excitation wavelength was 440 nm for the fluorescence emission spectra in panel B.
© Copyright Policy
Related In: Results  -  Collection

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

life-05-00004-f002: Absorption spectra (A) and low-temperature (77 K) fluorescence emission spectra (B) for Synechococcus sp. PCC 7335 cells grown in white light (WL, solid black line), red light (RL, solid red line), far-red light (FRL, solid blue line), and FRL with 1 mM fructose added to the growth medium (dotted blue line). The excitation wavelength was 440 nm for the fluorescence emission spectra in panel B.
Mentions: Like Leptolyngbya JSC-1, Synechococcus sp. PCC 7335 is a phycoerythrin-producing strain that is known to perform type-III CCA [31,32]. To determine whether this marine cyanobacterium could also perform FaRLiP, cells were grown under different light conditions. Figure 2A shows whole-cell absorption spectra for Synechococcus sp. PCC 7335 cells that had been grown in WL, 645-nm RL, and 720-nm FRL (±1 mM fructose). The absorption spectrum of whole cells grown in WL had much higher absorption at ~569 nm due to phycoerythrin and much less absorption at 625 nm compared to cells grown in 645-nm RL. These cells were brown and blue-green in color, respectively, which is consistent with previous studies that have shown that Synechococcus sp. PCC 7335 is capable of Type-III CCA [31,32]. Cells grown in 720-nm FRL, with or without 1 mM fructose present, had very similar absorption spectra (Figure 2A). The blue-green colored cells exhibited an absorption feature extending from 700 nm to 800 nm with a maximum at ~707 nm that was not observed for cells grown under WL and 645-nm RL conditions. Figure 2B shows the low-temperature fluorescence emission spectra of the same Synechococcus sp. PCC 7335 cells. Cells grown in WL and 645-nm RL had nearly identical fluorescence emission spectra, which exhibited maxima at 683 and 695 nm for PS II and 724 nm for PS I. Cells grown in 720-nm FRL (± 1 mM fructose) had a very sharp and intense fluorescence emission maximum at 738 nm with lesser maxima at 716 nm and 683 nm and rather minimal emission at 695 nm. These fluorescence emission properties are similar to those Leptolyngbya JSC-1 cells producing Chl d and Chl f, except that the major Chl emission peak is blue-shifted about 10 nm [28]. These absorption and fluorescence emission results indicate that Synechococcus sp. PCC 7335 synthesizes different pigments and/or assembles different photosynthetic complexes with absorption beyond 700 nm when cells are grown in FRL.

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