The Effect of Ethylene on the Growth and Development of Wild-type and Mutant Arabidopsis thaliana (L.) Heynh

Some developmental responses of wild-type and mutant strains of Arabidopsis thaliana to ethylene have been investigated (shoot and root elongation, isodiametric cell expansion, plumular hook angle, ethylene biosynthesis, peroxidase activity). One such mutant (eti 5) shows little or no response to ethylene at concentrations up to 10000 μl 1−1 in any test; the other mutants show reduced responses. The ability of germinated seedlings to emerge through sand is directly proportional to their sensitivity to ethylene. It is suggested that this finding supports the hypothesis that increased ethylene production in response to mechanical impedance is involved, via its effects on stem thickening and hook closure, in the emergence process.