ROOT HAIR DEFECTIVE SIX-LIKE4 (RSL4) is necessary and sufficient for root hair elongation in Arabidopsis thaliana. Root hair length is determined by the duration for which RSL4 protein is present in the developing root hair. The aim of this research was to identify genes regulated by RSL4 that affect root hair growth. To identify genes regulated by RSL4, we identified genes whose expression was elevated by induction of RSL4 activity in the presence of an inhibitor of translation. Thirty-four genes were identified as putative targets of RSL transcriptional regulation, and the results suggest that the activities of SUPPRESSOR OF ACTIN (SAC1), EXOCSYT SUBUNIT 70A1 (EXO70A1), PEROXIDASE7 (PRX7) and CALCIUM-DEPENDENT PROTEIN KINASE11 (CPK11) are required for root hair elongation. These data indicate that RSL4 controls cell growth by controlling the expression of genes encoding proteins involved in cell signalling, cell wall modification and secretion.
Keywords: Arabidopsis cell growth; CALCIUM-DEPENDENT PROTEIN KINASE11 (CPK11); EXOCSYT SUBUNIT 70A1 (EXO70A1); PEROXIDASE7 (PRX7); ROOT HAIR DEFECTIVE SIX-LIKE4 (RSL4); SUPPRESSOR OF ACTIN (SAC1); basic helix-loop-helix transcription factor; root hair.
© 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.