Identification and Characterization of the PAP Gene Family in wheat (Triticum aestivum L.)

Abstract

Abstract Purple acid phosphatases (PAPs), which are a family of metallo-phosphoesterase enzymes, are involved in phosphorus nutrition in plants. In this study, 9 low molecular weight (LMW) PAPs and 30 high molecular weight (HMW) PAPs were found, and these PAPs were classified into four subfamilies: 5 in sub. Ia-2, 9 in sub. Ib-1, 16 in sub. Ib-2, and 9 in sub. IIIb. Similar gene structures and conserved protein motifs of TaPAPs in wheat were identified in the same subfamilies. Bioinformatic analyses revealed that the functions of different subgroup TaPAPs in wheat were multiple, and 9 TaPAPs could be secretory phosphatase due to its coding region contain a signal peptide and an N-terminal transmembrane helix. The expression patterns analysis showed that 17 TaPAP genes were constitutive expressed in wheat different tissues, the others were expressed in a tissue-specific manner. Interestingly, we found that one triplet TaPAPs named TaPAP4-4A/4B/4D, which belong to sub. IIIb, were highly expressed in root, spike, leaf and seed. The TaPAP4-4A gene was cloned and transplanted to Arabidopsis to assess the roles of sub. IIIb memebers. The results showed that TaPAP4-4A not only promote growth and development, but also increases the resistant to Pi-deficient stress by secreting more phosphatase. The aforementioned findings offer a scientific basis for the thorough comprehension of the wheat TaPAP gene family, which is beneficial for screening further candidate genes and developing new low phosphorus tolerant wheat types.