INHIBITION OF ETHYLENE BIOSYNTHESIS DOES NOT BLOCK MICROTUBULE REORIENTATION 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 pr eceded by a re-orientation of microtubules in the affected cells. In a n approach to understand the control of this process it was investigat ed whether or not the plant hormone ethylene plays a role in the re-or ientation of microtubules and growth polarity. Our results show that t reating pea roots with an inhibitor of ethylene synthesis, L-alpha-(2- aminoethyoxyvinyl)-glycine hydrochloride (AVG), did not affect wound-i nduced microtubule re-orientation. However, the effect of AVG on ethyl ene synthesis in pea roots was confirmed by its stimulation of root el ongation. Therefore we conclude that increased ethylene production, wh ich has been observed previously in wounded tissues, is unlikely to be a control factor in microtubule re-orientation in this system.