Table 1.

Arabidopsis Mutants Implicated in IBA Transport.

Mutant	Gene product	Mutant phenotype	References
pdr8 / pen3 / abcg36	At1g59870 plasma membrane ABC transporter; IBA effluxer	IBA and 2,4-dichlorophenoxybutyric acid (2,4-DB) hypersensitivity; reduced IBA efflux from root tips; long root hairs	Strader and Bartel, 2009
pdr9 / eta4 / pis1 / abcg37	At3g53480 plasma membrane ABC transporter; IBA effluxer	IBA, 2,4-D, 2,4-DB, and TIBA hypersensitivity; reduced IBA efflux from root tips	Ito and Gray, 2006; Strader et al., 2008; Růžička et al., 2010
pxa1 / cts1 / acn2 / ped3 / abcd1	At4g39850 peroxisomal ABC transporter; moves IBA (and other substrates) into peroxisome	IBA resistance; reduced lateral root formation; decreased filament elongation; fatty acid β-oxidation defects	Hayashi et al., 1998; Zolman et al., 2001; Footitt et al., 2002; Hooks et al., 2004; Footitt et al., 2007
rib1	Unidentified	IBA and 2,4-D resistance; altered IBA transport; gravity response defects	Poupart and Waddell, 2000; Poupart et al., 2005