Protein PHOSPHATASE 2C family consists of a group of evolutionary-conserved serine/threonine PHOSPHATASEs which play a role in stress signal transduction. A subfamily of this protein PHOSPHATASEs in Arabidopsis, including ABI1 and ABI2, are known as components of Abscisic acid signal transduction pathway. Their mutants are hypersensitive to ABA showing an increased expression during seed dormancy and adaptive responses to drought. Considering sensitivity of rice to abiotic stresses, particularly drought, identification of this gene family in rice and studying their role in response to stress would be beneficial. In this research, nine OsPP2C proteins (OsPP2C1 to OsPP2C9), carrying all the conserved motifs of this subfamily were found in rice, Among them, only OsPP2C5 transcript levels were significantly up-regulated by drought and abscisic acid which is down-regulated by re-watering or ABA removal. Drought stress induced OsPP2C5 gene expression in all the studied tissues. Based on the RNA in situ hybridization experiments, OsPP2C5 transcripts were observed in almost all cells and accumulated more in the nuclei in divisional zone of the drought stressed peduncles. However, the transcripts of this gene were accumulated at higher levels in the primary and secondary vascular bundles, phloem and xylem parenchyma, epidermal cells and sclerenchyma/ chlorenchyma precursors. Based on the achieved results, the OsPP2C5 gene seems to play a role in ABA/ drought stress signal transduction. It is expected that appropriate genetic manipulations of this gene family would increase rice tolerance to abiotic stresses.

Introduction: This study was performed to establish a complementary method to the diagnosis of complete hydatidiform mole and its differentiation from the other cases of gestational trophoblastic disease by measuring the total (ALP) and placental alkaline PHOSPHATASE (PLAP) specific activity. Materials and Methods: Serum and tissue extracts from 13 patients, 13 normal non-pregnant and 30 pregnant females were compared for these enzymes activities. Paranitrophenyl phosphate was used as substrate. Placental alkaline PHOSPHATASE was simply distingushed from its isoenzymes by its heat stability (65°c for 15min).Results: According to our findings from serum and tissue extract examination the activity of total alkaline PHOSPHATASE and placental alkaline PHOSPHATASE activities were reduced in hydatidiform mole patients in comparsion with pregnant females (P<0.05) but there was no significant difference in non - pregnant subject. Conclusion: These results show a severe hypophosphatasia in serum and tissue extracts of the patients. The reduction in activity of enzymes may be caused by low synthesis of enzyme by trophoblast cells or some post transcriptional changes that causse the reduction of enzyme activity. Since the ALP is probably important in active transport of suger and phosphate across the trophoblast cell membreanes, so the hydropic villi of hydatidiform mole placenta may due to reduction of enzyme activity in placental villi. Our results suggest that measurment of ALP and PLAP activity in serum and tissue extract can be a complementary method in diagnosis of hydatidiform mole.

Introduction: Production of Monoclonal antibody against Alkaline PHOSPHATASE for application in immunohistochemical and immunocytochemical techniques such as alkaline PHOSPHATASE anti-alkaline PHOSPHATASE (APAAP) method.   Material and Methods: In this investigation female Balb/c mice were immunized by several injections of alkaline PHOSPHATASE and the antibody titer in their sera were measured after each injection. The spleen lymphocytes of immunized mice and Sp2/0 myeloma cells were fused using 50% polyethylen glycol as fusing agent and hybridoma cells were selected by HAT medium. Identification and selection of anti-alkaline PHOSPHATASE producing clones were done by performing ELISA test on supernatants of all the resulting clones. Limiting dilution was performed twice on antiboby producing clones for their seperation and the resulted subclones were propagated. Since APAAP complex must be enzymatically active for using in immunohistochemical techniques the adhesion of Ab molecule to enzyme molecule must not affect the enzyme activity. For investigation of this effect, an ELISA technique was planned and the supernatants of selected hybridoma clones were studied by this method. For production of concentrated Ab the hybridoma cells were injected to peritoneal cavity of mice and the ascetic fluids were obtained. Finally the antibodies isotypes were determined.   Results: After 6 fusion experiments 104 hybridoma clones were abtained and two clones (A1G9 and A1G8) which were antibody producing and had the highest absorbance in ELISA test were selected. Using the limiting dilution method finally two monoclonal subclones A1G8F7 and A1G9G3 were selected. ELISA experiments showed that antibodies which were produced by selected hybridoma clones did not react with active site of the enzyme and did not interfer with enzymatic activity. Electrophoresis of ascetic fluids of hybridoma injected mice showed a prominent band in γ position. Isotype determination of monoclonal antibodies showed that both hybridoma clones produce antibody from IgG class with k light chain.   Conclusion: Because monoclonal antibodies which are produced by the obtained hybridoma cell lines are from IgG class and do not affect the enzyme activity, it seem's that they are suitable for APAAP complex formation. Other steps of this study are now being performed until APAAP complex formation and it's application in immunohistochemistry.