In Synechococcus sp. competition for energy between assimilation and acquisition of C and those of N only occurs when growth is light limited

Zuoxi Ruan, John A. Raven, Mario Giordano (Lead / Corresponding author)

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The carbon-concentrating mechanisms (CCMs) of cyanobacteria counteract the low CO2 affinity and CO2:O2 selectivities of the Rubisco of these photolithotrophs and the relatively low oceanic CO2 availability. CCMs have a significant energy cost; if light is limiting, the use of N sources whose assimilation demands less energy could permit a greater investment of energy into CCMs and inorganic C (Ci) assimilation. To test this, we cultured Synechococcus sp. UTEX LB 2380 under either N or energy limitation, in the presence of NO3- or NH4+. When growth was energy-limited, NH4+-grown cells had a 1.2-fold higher growth rate, 1.3-fold higher dissolved inorganic carbon (DIC)-saturated photosynthetic rate, 19% higher linear electron transfer, 80% higher photosynthetic 1/K1/2(DIC), 2.0-fold greater slope of the linear part of the photosynthesis versus DIC curve, 3.5-fold larger intracellular Ci pool, and 2.3-fold higher Zn quota than NO3--grown cells. When energy was not limiting growth, there were not differences between NH4+- and NO3--grown cells, except for higher linear electron transfer and larger intracellular Ci pool.We conclude that, when energy limits growth, cells that use the cheaper N source divert energy from N assimilation to C acquisition and assimilation; this does not happen when energy is not limiting.

Original languageEnglish
Pages (from-to)3829-3839
Number of pages11
JournalJournal of Experimental Botany
Volume68
Issue number14
Early online date28 Mar 2017
DOIs
Publication statusPublished - 1 Jun 2017

Fingerprint

Synechococcus
assimilation (physiology)
Carbon
Light
energy
Growth
carbon
concentrating
Electrons
electron transfer
Ribulose-Bisphosphate Carboxylase
Photosynthesis
Cyanobacteria
energy costs
cells
ribulose-bisphosphate carboxylase
Costs and Cost Analysis
cell growth
photosynthesis

Keywords

  • Ammonium
  • CO2 concentrating mechanisms (CCMs)
  • Cyanobacteria
  • Internal carbon pool
  • Nitrate

Cite this

@article{76537cbb01204b34b47e71215e6e2c04,
title = "In Synechococcus sp. competition for energy between assimilation and acquisition of C and those of N only occurs when growth is light limited",
abstract = "The carbon-concentrating mechanisms (CCMs) of cyanobacteria counteract the low CO2 affinity and CO2:O2 selectivities of the Rubisco of these photolithotrophs and the relatively low oceanic CO2 availability. CCMs have a significant energy cost; if light is limiting, the use of N sources whose assimilation demands less energy could permit a greater investment of energy into CCMs and inorganic C (Ci) assimilation. To test this, we cultured Synechococcus sp. UTEX LB 2380 under either N or energy limitation, in the presence of NO3- or NH4+. When growth was energy-limited, NH4+-grown cells had a 1.2-fold higher growth rate, 1.3-fold higher dissolved inorganic carbon (DIC)-saturated photosynthetic rate, 19{\%} higher linear electron transfer, 80{\%} higher photosynthetic 1/K1/2(DIC), 2.0-fold greater slope of the linear part of the photosynthesis versus DIC curve, 3.5-fold larger intracellular Ci pool, and 2.3-fold higher Zn quota than NO3--grown cells. When energy was not limiting growth, there were not differences between NH4+- and NO3--grown cells, except for higher linear electron transfer and larger intracellular Ci pool.We conclude that, when energy limits growth, cells that use the cheaper N source divert energy from N assimilation to C acquisition and assimilation; this does not happen when energy is not limiting.",
keywords = "Ammonium, CO2 concentrating mechanisms (CCMs), Cyanobacteria, Internal carbon pool, Nitrate",
author = "Zuoxi Ruan and Raven, {John A.} and Mario Giordano",
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In Synechococcus sp. competition for energy between assimilation and acquisition of C and those of N only occurs when growth is light limited. / Ruan, Zuoxi; Raven, John A.; Giordano, Mario (Lead / Corresponding author).

In: Journal of Experimental Botany, Vol. 68, No. 14, 01.06.2017, p. 3829-3839.

Research output: Contribution to journalArticle

TY - JOUR

T1 - In Synechococcus sp. competition for energy between assimilation and acquisition of C and those of N only occurs when growth is light limited

AU - Ruan, Zuoxi

AU - Raven, John A.

AU - Giordano, Mario

N1 - This work was funded by grant 27-12-2011 MAE-MOST and by grants GIO2010 and GIO2011 Ricerca Scientifica di Ateneo UNIVPM, all to M.G.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - The carbon-concentrating mechanisms (CCMs) of cyanobacteria counteract the low CO2 affinity and CO2:O2 selectivities of the Rubisco of these photolithotrophs and the relatively low oceanic CO2 availability. CCMs have a significant energy cost; if light is limiting, the use of N sources whose assimilation demands less energy could permit a greater investment of energy into CCMs and inorganic C (Ci) assimilation. To test this, we cultured Synechococcus sp. UTEX LB 2380 under either N or energy limitation, in the presence of NO3- or NH4+. When growth was energy-limited, NH4+-grown cells had a 1.2-fold higher growth rate, 1.3-fold higher dissolved inorganic carbon (DIC)-saturated photosynthetic rate, 19% higher linear electron transfer, 80% higher photosynthetic 1/K1/2(DIC), 2.0-fold greater slope of the linear part of the photosynthesis versus DIC curve, 3.5-fold larger intracellular Ci pool, and 2.3-fold higher Zn quota than NO3--grown cells. When energy was not limiting growth, there were not differences between NH4+- and NO3--grown cells, except for higher linear electron transfer and larger intracellular Ci pool.We conclude that, when energy limits growth, cells that use the cheaper N source divert energy from N assimilation to C acquisition and assimilation; this does not happen when energy is not limiting.

AB - The carbon-concentrating mechanisms (CCMs) of cyanobacteria counteract the low CO2 affinity and CO2:O2 selectivities of the Rubisco of these photolithotrophs and the relatively low oceanic CO2 availability. CCMs have a significant energy cost; if light is limiting, the use of N sources whose assimilation demands less energy could permit a greater investment of energy into CCMs and inorganic C (Ci) assimilation. To test this, we cultured Synechococcus sp. UTEX LB 2380 under either N or energy limitation, in the presence of NO3- or NH4+. When growth was energy-limited, NH4+-grown cells had a 1.2-fold higher growth rate, 1.3-fold higher dissolved inorganic carbon (DIC)-saturated photosynthetic rate, 19% higher linear electron transfer, 80% higher photosynthetic 1/K1/2(DIC), 2.0-fold greater slope of the linear part of the photosynthesis versus DIC curve, 3.5-fold larger intracellular Ci pool, and 2.3-fold higher Zn quota than NO3--grown cells. When energy was not limiting growth, there were not differences between NH4+- and NO3--grown cells, except for higher linear electron transfer and larger intracellular Ci pool.We conclude that, when energy limits growth, cells that use the cheaper N source divert energy from N assimilation to C acquisition and assimilation; this does not happen when energy is not limiting.

KW - Ammonium

KW - CO2 concentrating mechanisms (CCMs)

KW - Cyanobacteria

KW - Internal carbon pool

KW - Nitrate

U2 - 10.1093/jxb/erx074

DO - 10.1093/jxb/erx074

M3 - Article

VL - 68

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EP - 3839

JO - Journal of Experimental Botany

JF - Journal of Experimental Botany

SN - 0022-0957

IS - 14

ER -