CRL4 regulates crown root formation through auxin transport in rice

• DOI: 10.3117/plantroot.2.19
• Publication Date: 2008-06-24T05:52:47Z
• Authors: Yuka Kitomi; Atsushi Ogawa; Hidemi Kitano; Yoshiaki Inukai
• Keywords: Lateral root; Gravitropism; Polar auxin transport

Adventitious (crown) roots account for the majority of root system monocots. It is reported that auxin plays an important role in formation crown roots, but underlying molecular mechanisms are still unknown. We characterized a rice (Oryza sativa L.) mutant rootless4 (crl4) was found to have defective formation. Besides reduced number, crl4 showed auxin-related abnormal phenotypical character-istics such as lateral number and impaired gravitropism. CRL4 encodes protein highly homologous with Arabidopsis GNOM, which mediates auxin-dependent plant growth by coordinating polar localization efflux carrier PIN1. In mutant, transport shoots roots. Besides, GUS staining controlled DR5 promoter node fainter spread wider than wild-type. These results indicate maintaining appropriate accumulation gradient through basal portion essential rice.