Abstract
Purple acid phosphatases (PAP) are involved in the metallo-phosphoesterase family, characterized as the conserved seven amino-acid residues with two metals. We isolated the four cDNAs encoding tobacco PAP (NtPAP) and determined the levels of PAP mRNAs during the wall regeneration of tobacco protoplasts. In this study, we confirmed purple-colored NtPAP12, insensitive to tartrate, Ca2+ and Mg2+ on the activity of acid phosphatase. Brefeldin A prevented not only the wall regeneration but also the secretion of NtPAP12 in tobacco protoplasts during wall regeneration. The exogenous NtPAP12, however, promoted the wall regeneration even in the presence of Brefeldin A. Therefore, NtPAP12 probably promotes cell wall deposition at the apoplastic space of tobacco cells.
