AN ANTIBODY RAISED TO A MAIZE AUXIN-BINDING PROTEIN HAS INHIBITORY EFFECTS ON CELL-DIVISION OF TOBACCO MESOPHYLL PROTOPLASTS

An antibody raised to the auxin-binding protein Zm-ERabp1 from maize c oleoptiles (anti-abp1 IgG) was tested for its effect on cell division of protoplasts prepared from tobacco (Nicotiana tabacum, cv. Xanthi) m esophyll. It was formerly demonstrated that this antibody is able to i nteract with an auxin-perception unit located at the plasma membrane a nd involved in the early electrical response of protoplasts to auxin. In different situations where auxin stimulates cell division, dual inh ibitory effects by anti-abp1 IgGs were observed on occurrence of first cell division, an early event, and on size of protoplast-derived micr ocolonies, a delayed response. This latter response is likely associat ed in its origin and mechanisms to the inhibition of first division.