TABLE 2 

Prochlorococcus metabolic pathways with transcripts that were consistently enriched during the first 5 h of extended darknessa

Condition and pathwaybTranscript(s) in pathway exhibiting significant differential enrichmentP valuec
Enriched in both axenic cultures and coculture
    Acetyl-CoA biosynthesis, carboxylate degradationacoA, lpd, pdhB1.3E−02
    Degradation/utilization/assimilationacoA, deoC, gldA, glpX, gltB, lpd, murQ, pdhB, pgi, prkB, rpi, tpiA, truB,
PMN2A_1709, PMN2A_1584
6.6E−02
    Generation of precursor metabolites and energyacnB, acoA, glpX, icd, lpd, ndhH, petC, petD, pgi, pdhB, prkB, psaD, psbB,
pykF, rpi, tal, tpiA, PMN2A_1709
1.7E−02
    Secondary metabolite biosynthesisdxs, gldA, ispE, ispG, lytB, pykF, tpiA4.6E−02
    Sugar degradationdeoC, pgi, PMN2A_17093.0E−03
Enriched only in axenic cultures
    Alcohol biosynthesis degradation,
glycerol degradation
gldA, pykF, tpiA1.5E−02
    CO2 fixationglpX, prkB, rpi, tpiA1.2E−02
    Fatty acid and lipid biosynthesisaccA, accC, fabI, lpxC, PMN2A_17851.5E−02
    FermentationacnB, icd, pdhB, pykF, PMN2A_17091.0E−03
    PhotosynthesisglpX, tpiA, prkB, rpi, psaD, psbB, petD2.0E−03
    RespirationacnB, icd, lpd, pdhB, pykF4.0E−02
    RubisCO shuntprkB, pykF, rpi5.5E−02
    Unsaturated fatty acid biosynthesisfabI, PMN2A_17853.6E−02
Enriched only in coculture
    Adenine and adenosine salvageapt6.8E−02
    Lipoate salvagelplA6.8E−02
    Proteinogenic amino acid degradationlpd, gltB, PMN2A_17091.0E−01
    Purine nucleotide degradationtruB6.8E−02
    Terpenoid biosynthesisdxs, ispG, ispE, lytB6.0E−03
    Tetrapyrrole biosynthesishemB, hemD7.5E−02
  • a Prochlorococcus metabolic pathways with transcripts that were consistently enriched during the first 5 h of extended darkness (36- and 40-h time points) relative to the controls grown on a 13:11 diel light:dark cycle. Additional details on these and other significantly enriched transcripts can be found in Table S3.

  • b Pathway definitions are from BioCyc (75). Acetyl-CoA, acetyl-coenzyme A.

  • c P value indicates the result of a Fisher significance test (PathwayTools).