Zimmermann P, Regierer B, Kossmann J, Frossard E, Amrhein N, Bucher M
Swiss Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Experimental Station Eschikon, 8315 Lindau, Switzerland.
Plant Biol (Stuttg). 2004 Sep;6(5):519-28. doi: 10.1055/s-2004-821091.
Three cDNAs encoding purple acid phosphatase (PAP) were cloned from potato (Solanum tuberosum L. cv. Désirée) and expression of the corresponding genes was characterised. StPAP1 encodes a low-molecular weight PAP clustering with mammalian, cyanobacterial, and other plant PAPs. It was highly expressed in stem and root and its expression did not change in response to phosphorus (P) deprivation. StPAP2 and StPAP3 code for high-molecular weight PAPs typical for plants. Corresponding gene expression was shown to be responsive to the level of P supply, with transcripts of StPAP2 and StPAP3 being most abundant in P-deprived roots or both stem and roots, respectively. Root colonisation by arbuscular mycorrhizal fungi had no effect on the expression of any of the three PAP genes. StPAP1 mRNA is easily detectable along the root axis, including root hairs, but is barely detectable in root tips. In contrast, both StPAP2 and StPAP3 transcripts are abundant along the root axis, but absent in root hairs, and are most abundant in the root tip. All three PAPs described contain a predicted N-terminal secretion signal and could play a role in extracellular P scavenging, P mobilisation from the rhizosphere, or cell wall regeneration.
从马铃薯（Solanum tuberosum L. cv. Désirée）中克隆出了三个编码紫色酸性磷酸酶（PAP）的cDNA，并对相应基因的表达进行了表征。StPAP1编码一种低分子量PAP，与哺乳动物、蓝细菌和其他植物的PAP聚类。它在茎和根中高度表达，其表达不会因缺磷（P）而改变。StPAP2和StPAP3编码植物典型的高分子量PAP。相应的基因表达显示对磷供应水平有响应，StPAP2和StPAP3的转录本分别在缺磷的根中或茎和根中最为丰富。丛枝菌根真菌对根的定殖对这三个PAP基因中任何一个的表达都没有影响。StPAP1 mRNA在根轴上很容易检测到，包括根毛，但在根尖几乎检测不到。相比之下，StPAP2和StPAP3的转录本在根轴上都很丰富，但在根毛中不存在，并且在根尖中最为丰富。所描述的所有三种PAP都含有一个预测的N端分泌信号，可能在细胞外磷清除、根际磷动员或细胞壁再生中发挥作用。
