Table II.

Summary of root and nodule phenotypes of skl and sunn mutants

The table shows the phenotypes of each mutant compared to wild-type plants. Phenotypes indicated in bold are different between skl and sunn. ND, Not determined; pi, post inoculation; WT, wild type.

PhenotypeSkl Compared to WTSunn Compared to WT
Uninoculated roots
    Root lengthLongeraShorterbc
    Long distance auxin transportSimilaraIncreasedb
    Local auxin transportLoweraSimilarb
    PIN1 and 2 expressionSimilaraSimilard
    Auxin transport inhibition by NPASimilaraSimilarb
    Auxin transport inhibition by ACCLess sensitive (insensitive)aND
    Inhibition of root growth by ethyleneLess sensitiveeLess sensitivec
S. meliloti inoculated roots
    Nodule numbersHigheraHigherb
    Nodule distributionFirst inoculation zoneaeAlong whole rootbc
    Nodule position (radial)Across entire rootceOpposite xylem poles onlyc
    Nodulation phenotype controlled byRootaShootc
    Long distance auxin transport (24 h pi)Less (not) inhibited by rhizobiaaLess (not) inhibited by rhizobiab
    Local auxin transport (4 h pi)SimilaraSimilarb
    Local auxin transport (24 h pi)HigheraSimilarb
    PIN 1 and 2 expression (24 h pi, inoculation zone)HigheraSimilard
    GH3 expression (4–84 pi)HighercHigherc
    Root growth inhibition by auxinLess sensitiveaSimilarb
    Inhibition of nodulation by auxinSimilar (IAA, NAA, 2,4D), but more sensitive (IBA)aSimilar (IAA, NAA, 2,4D; ND for IBA)b
    Root growth inhibition by NPALess sensitiveaSimilarb
    Inhibition of nodulation by NPALess sensitiveaMore sensitiveb
    Inhibition of nodulation by ethyleneLess sensitiveeSimilarc
  • a This study.

  • b van Noorden et al. (2006).

  • c Penmetsa et al. (2003).

  • d G. van Noorden, personal communication.

  • e Penmetsa and Cook (1997).