Changes in protein methylation associated with the elicitation response in cell cultures of alfalfa ( Medicago sativa L.)

The methylation of endogenous proteins increased in alfalfa cell suspension cultures following treatment with a fungal elicitor. Carboxyl methylation, a post‐translational modification associated with controlling the localisation and longevity of proteins, was the dominant form of protein methylation in both elicited and unelicited cells. Protein methylation was restricted to a limited number of peptides prior to elicitor treatment but as elicitation progressed the number of endogenous substrates increased. Increases resulted from a combination of an elicitor‐dependent increase in the activity of a protein carboxyl methyltransferase and the accumulation of preferred endogenous substrates in the latter stages of elicitation.