State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou, China.
Plant Biol (Stuttg). 2011 Jan;13(1):7-15. doi: 10.1111/j.1438-8677.2010.00346.x.
Purple acid phosphatases (PAPs) are a family of metallo-phosphoesterases involved in a variety of physiological functions, especially phosphate deficiency adaptations in plants. We identified 26 putative PAP genes by a genome-wide analysis of rice (Oryza sativa), 24 of which have isolated EST sequences in the dbEST database. Amino acid sequence analysis revealed that 25 of these genes possess sets of metal-ligating residues typical of known PAPs. Phylogenetic analysis classified the 26 rice and 29 Arabidopsis PAPs into three main groups and seven subgroups. We detected transcripts of 21 PAP genes in roots or leaves of rice seedlings. The expression levels of ten PAP genes were up-regulated by both phosphate deprivation and over-expression of the transcription factor OsPHR2. These PAP genes all contained one or two OsPHR2 binding elements in their promoter regions, implying that they are directly regulated by OsPHR2. Both acid phosphatase (AP) and surface secretory acid phosphatase (SAP) activity assays showed that the up-regulation of PAPs by Pi starvation, OsPHR2 over-expression, PHO2 knockout or OsSPX1 RNA interference led to an increase in AP and SAP activity in rice roots. This study reveals the potential for developing technologies for crop improvement in phosphorus use efficiency.
紫色酸性磷酸酶（PAPs）是一类参与多种生理功能的金属磷酸酯酶，尤其在植物的磷酸盐缺乏适应中发挥重要作用。我们通过对水稻（Oryza sativa）的全基因组分析，鉴定出 26 个假定的 PAP 基因，其中 24 个在 dbEST 数据库中具有分离的 EST 序列。氨基酸序列分析表明，这些基因中的 25 个具有典型的已知 PAP 的金属配体残基。系统发育分析将 26 个水稻和 29 个拟南芥 PAP 分为三个主要组和七个亚组。我们在水稻幼苗的根或叶中检测到 21 个 PAP 基因的转录本。十个 PAP 基因的表达水平受到磷酸盐剥夺和转录因子 OsPHR2 过表达的上调。这些 PAP 基因在启动子区域都含有一个或两个 OsPHR2 结合元件，这表明它们受到 OsPHR2 的直接调控。酸性磷酸酶（AP）和表面分泌酸性磷酸酶（SAP）活性测定均表明，Pi 饥饿、OsPHR2 过表达、PHO2 敲除或 OsSPX1 RNA 干扰引起的 PAP 上调导致水稻根中 AP 和 SAP 活性增加。这项研究揭示了开发提高作物磷利用效率技术的潜力。
