Table I. Selected examples of genes that impact auxin homeostasis and are involved in root hair cell expansion.
ox, Overexpressor line.
| Gene Type | Mutant/Transgenic Line | Root Hair Phenotype | Reference |
|---|---|---|---|
| IAA transport | |||
| pin2 | Short root hairs | Cho et al. (2007a); Rigas et al. (2013) | |
| pEXP7a:PIN3ox | Long root hairs | Lee and Cho (2006) | |
| pEXP7a:PIN1/PIN2/PIN3/PIN7/PIN8 | Short root hairs | Ganguly et al. (2010) | |
| pEXP7a:PIN5 | Long root hairs | Ganguly et al.( 2010) | |
| pgp4 (abcb4) | Long root hairs | Santelia et al. (2005); Cho et al. (2007b, 2012) | |
| PGP4ox | Short root hairs | Cho et al. (2007b) | |
| aux1-7, aux1-T, aux1-22 | Short root hairs | Pitts et al. (1998); Ikeda et al. (2009); Jones et al. (2009) | |
| AUX1ox | Long root hairs | Ganguly et al. (2010) | |
| pEXP7a:PID | Short and fewer root hairs | Lee and Cho (2006) | |
| IAA ER storage | |||
| pils2 pils5 | Long root hairs | Barbez et al. (2012) | |
| PILS5-GFPox, EXP7a:PILS5-GFP | Short root hairs | Barbez et al. (2012) | |
| IAA metabolism | |||
| ibr1 ibr3 ibr10, ilr1 iar3 ill2 | Short root hairs | Davies et al. (1999); LeClere et al. (2002); Zolman et al. (2008); Strader et al. (2010b) | |
| echo2 ibr1ibr3 ibr10 | No root hairs | Strader et al. (2010b) | |
| ill2 ilr1 iar3 ibr1, ill2 iar3 ibr3 | Short root hairs | Spiess et al. (2014) | |
| mes17 ill2 iar3, mes17 ibr3 | Mild short root hair phenotype | Spiess et al. (2014) | |
| Iar4 | Short root hairs; rescued by YUCCA1ox | Quint et al. (2009) | |
| YUCCA1ox | Long root hair phenotype | Zhao et al. (2001) | |
| yucca1 yucca2 yucca4 yucca6 | Hairy root hair phenotype | Chen and Xiong (2009) | |
| IBA transport | |||
| cdcg36 (pen3, pdr8) | Long root hairs | Strader et al. (2011) | |
| IAA perception | |||
| tir1, tir1 afb2 afb3 | Short root hairs | Dharmasiri et al. (2005) | |
| pEXP7a:TIR1 | Longer root hairs | Ganguly et al. (2010) | |
| aux/iaa1 (axr5) | No root hairs | Park et al. (2002) | |
| aux/iaa7 (axr2) | No/short root hairs | Wilson et al. (1990); Timpte et al. (1994) | |
| aux/iaa14 (slr) | No/short root hairs | Fukaki et al. (2002) | |
| aux/iaa17 (axr3) | Short root hairs | Leyser et al. (1996) | |
| axr1 | Short root hairs | Pitts et al. (1998) | |
| iaa28 | Short root hairs | Rogg et al. (2001) | |
| IAA nontranscriptional response | |||
| fer | Short root hairs | Duan et al. (2010) | |
| ropGEF4/ropGEF10 | Short root hairs and reduced root hair density for ropGEF10 | Huang et al. (2013) | |
| IAA transcriptional response | |||
| rsl4/RSL4ox | Short root hairs/long root hairs | Yi et al. (2010) |