Suppl Figure 5 WT ctl1 WT ctl1 conditional defect NO3-, Cl-, sucrose Hermans et al. (2010) Low, moderate NO3- High NO3- Endogenous content/production ABA ↓ CK ↑ C2H4 ↑↑ Exogenous supply ABA induces the arm phenotype No different effect of IAA and CK compared to wt Endogenous content/production ABA -- CK ↑ ↑ C2H4 ↑ Exogenous supply ACC does not worsen arm phenotype Ag+ slightly increases PR length, prevents swelling and root hair, does not repress LRs. Suppl Fig. 5. Summary of the interplay between hormones and arm phenotype. Mutation in chitinase-like CTL1 results in cell elongation defects in the hypocotyls (induced by darkness) and in roots (upon restrictive conditions such as high nitrate and chloride supply, high C/N ratio and sucrose). Summary of the hormonal endogenous concentrations and exogenous supply effect on root phenotype of ctl1/arm compared to wt.