TABLE 5.

Distribution of gene orthologs in marine picocyanobacteria encoding proteins potentially involved in compatible solute synthesisa and transport

Genus and strain (clade)Presenceb of:Compatible solute accumulationc
ggpS, cluster 1610ggpP (stpA), cluster 1282ggtA, cluster 8069ggtB, cluster 1455ggtC, cluster 1454ggtD, cluster 1453proV, cluster 8061proW, cluster 1943proX, cluster 1944gpgP, cluster 1370gpgS, cluster 1368gbmt1, cluster 1941gbmt2, cluster 1942spsA, cluster 368spp, cluster 2483betP, cluster 1663
Synechococcus
    CC9311 (I)NI
    CC9605 (II)NI
    WH8102 (III)GG, GB
    CC9902 (IV)NI
    BL107 (IV)NI
    WH7803 (V)GG, Suc, GB
    WH7805 (VI)NI
    RS9917 (VIII)NI
    RS9916 (IX)NI
    WH5701 (5.2)2NI
    RCC307 (5.3)NI
Prochlorococcus
    MED4 (HLI)NI
    MIT9515 (HLI)NI
    AS9601 (HLII)NI
    MIT9215 (HLII)NI
    MIT9301 (HLII)NI
    MIT9312 (HLII)Suc, GGA
    NATL1A (LLI)NI
    NATL2A (LLI)Suc, GGA
    SS120 (LLII)Suc, GGA
    MIT9211 (LLIII)NI
    MIT9303 (LLIV)NI
    MIT9313 (LLIV)Suc, GB
  • a No clear homolog of functionally characterized trehalose biosynthetic genes from other bacteria could be found in these marine picocyanobacterial genomes.

  • b The presence of a single gene is indicated by a closed circle. Where multiple genes are present, the number is given. −, absent.

  • c The ability to accumulate specific compatible solutes was analyzed by gas-liquid chromatography in ethanol extracts from selected strains (Klähn and Hagemann, unpublished data). NI, not investigated. Suc, sucrose.