Plant Transcription factor database - Universität Potsdam
version: 3.0

Populus trichocarpa AUX/IAA Family


Tiwari et al. 2004: Aux/IAA proteins are short-lived nuclear proteins that repress expression of primary/early auxin response genes in protoplast transfection assays. Repression is thought to result from Aux/IAA proteins dimerizing with auxin response factor (ARF) transcriptional activators that reside on auxin-responsive promoter elements, referred to as AuxREs. Most Aux/IAA proteins contain four conserved domains, designated domains I, II, III, and IV. Domain II and domains III and IV play roles in protein stability and dimerization, respectively. A clear function for domain I had not been established. Results reported here indicate that domain I in Aux/IAA proteins is an active repression domain that is transferable and dominant over activation domains. An LxLxL motif within domain I is important for conferring repression. The dominance of Aux/IAA repression domains over activation domains in ARF transcriptional activators provides a plausible explanation for the repression of auxin response genes via ARF-Aux/IAA dimerization on auxin-responsive promoters.

Members of this family
  SHOULD possess AUX_IAA domain
  SHOULD NOT possess Auxin_resp B3 domains

Domain alignments

Benchmark against A. thaliana

The Sensitivity and Positive Predictive Value (PPV) were assessed for this family. The data reported by Remington et al. 2004 for A. thaliana were taken as gold standard.

The gold standard reported 29 members for this family, 28 of which are present in ArabTFDB, giving a PPV of 1.00. One additional member not present in ArabTFDB might be a false negative, giving a Sensitivity of 0.97.

This family is also present in:


There are 33 gene models in this family

Gene modelDescriptionDomains
171693 gw1.I.293.1 AUX_IAA
180980 gw1.I.9580.1 AUX_IAA
180995 gw1.I.9595.1 AUX_IAA
205684 gw1.V.1085.1 AUX_IAA
225356 gw1.X.53.1 AUX_IAA
229927 gw1.X.4624.1 AUX_IAA
241272 gw1.XIII.1521.1 AUX_IAA
260267 gw1.XVIII.808.1 AUX_IAA
294718 gw1.70.171.1 AUX_IAA
417811 gw1.VI.2184.1 AUX_IAA
561907 eugene3.00061866 AUX_IAA
564913 eugene3.00081508 AUX_IAA
566151 eugene3.00100709 AUX_IAA
578920 eugene3.00181144 AUX_IAA
584053 eugene3.01570047 AUX_IAA
595419 eugene3.00700060 AUX_IAA
640933 grail3.0052008101 AUX_IAA
643213 grail3.0003037201 AUX_IAA
644939 grail3.0050017401 AUX_IAA
646006 grail3.0037017201 AUX_IAA
664248 grail3.0061005101 AUX_IAA
709610 estExt_Genewise1_v1.C_LG_I9550 AUX_IAA
710452 estExt_Genewise1_v1.C_LG_II1635 AUX_IAA
711734 estExt_Genewise1_v1.C_LG_III0268 AUX_IAA
720961 estExt_Genewise1_v1.C_LG_VIII2464 AUX_IAA
726443 estExt_Genewise1_v1.C_LG_X5603 AUX_IAA
762175 fgenesh4_pg.C_LG_VI000485 AUX_IAA
798526 fgenesh4_pm.C_LG_II000215 AUX_IAA
803776 fgenesh4_pm.C_LG_VIII000731 AUX_IAA
823671 estExt_fgenesh4_pg.C_LG_XIII0196 AUX_IAA
830259 estExt_fgenesh4_pm.C_LG_II0495 AUX_IAA
830678 estExt_fgenesh4_pm.C_LG_III0099 AUX_IAA
831610 estExt_fgenesh4_pm.C_LG_V0528 AUX_IAA

General references

Liscum, E; Reed, JW. 2002. Genetics of Aux/IAA and ARF action in plant growth and development. Plant Mol. Biol. 49(3-4):387-400 PUBMEDID:12036262
Tiwari, SB; Hagen, G; Guilfoyle, TJ. 2004. Aux/IAA proteins contain a potent transcriptional repression domain. Plant Cell 16(2):533-43 PUBMEDID:14742873
Tiwari, SB; Wang, XJ; Hagen, G; Guilfoyle, TJ. 2001. AUX/IAA proteins are active repressors, and their stability and activity are modulated by auxin. Plant Cell 13(12):2809-22 PUBMEDID:11752389

Specific references

Kalluri, UC; Difazio, SP; Brunner, AM; Tuskan, GA. 2007. Genome-wide analysis of Aux/IAA and ARF gene families in Populus trichocarpa. BMC Plant Biol. 7:59 PUBMEDID:17986329