Abstract：Purple acid phosphatases (PAPs), member of the metallo-phosphoesterase family, are involved in catalyzing the hydrolysis of various phosphate esters or anhydrides and play important role in external phosphorus assimilation and recycling P in plants. In this study, comparative genomics method was used to identify maize(Zea mays) ZmPAPs family in whole-genome scale based on the PAPs orthologs in Arabidopsis thaliana. The gene structure and phylogenetic relationship of ZmPAPs had been analyzed. The methods of sqRT-PCR, qRT-PCR and subcellular localization were performed for further study of ZmPAPs family members. The results showed that 24 ZmPAPs were identified from whole genome sequences of maize inbred line B73 and could be classified into 3 distinct groups including 8 subgroups based on amino acid sequences. Eight ZmPAPs which were analyzed by sqRT-PCR all exhibited differential expression under low phosphorus starvation. The expression profiles of 4 ZmPAPs (ZmPAP1c, ZmPAP10a, ZmPAP10b and ZmPAP26) with significant levels of differential expression were assayed by qRT-PCR and indicated that 4 ZmPAPs exhibited different expression profiles in different organs and genotypes under low phosphorus stress, among them ZmPAP1c and ZmPAP10a played important role in maintaining phosphorus homeostasis. Subcellular location analysis revealed that the products of ZmPAP1c and ZmPAP10a located in cell membrane. The analysis of acid phosphatase (APase) activity showed that APase activity in maize 178 roots was higher than that of maize 9782 and maize 178 was more sensitive than maize 9782 in responses to phosphorus starvation, indicating that the low-phosphorus tolerant maize enhanced the APase activity through regulating the expression of ZmPAPs to improve P utilization efficiency under the stress of phosphorus deprivation. In conclusion, this work provides basic data for further study on ZmPAPs family.
