Inhibition of ethylene biosynthesis does not block microtubule re-orientation in wounded pea roots

Wounds in pea roots can cause the cortical cells surrounding the wound to change their direction of elongation and division planes in order to replace the removed tissue. These changes in growth polarity are preceded by a re-orientation of microtubules in the affected cells. In an approach to understand the control of this process it was investigated whether or not the plant hormone ethyl-ene plays a role in the re-orientation of microtubules and growth polarity. Our results show that treating pea roots with an inhibitor of ethylene synthesis, L-a-(2-aminoethyoxyvinyl)-glycine hydrochloride (AVG), did not affect wound-induced microtubule re-orientation. However, the effect of AVG on ethylene synthesis in pea roots was confirmed by its stimulation of root elongation. Therefore we conclude that increased ethylene production, which has been observed previously in wounded tissues, is unlikely to be a control factor in microtubule re-orientation in this system.