Differential expression of three purple acid phosphatases from potato.
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.
Zimmermann
P
P
Swiss Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Experimental Station Eschikon, 8315 Lindau, Switzerland.
Regierer
B
B
Kossmann
J
J
Frossard
E
E
Amrhein
N
N
Bucher
M
M
D000135:Acid Phosphatase / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006023:Glycoproteins / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000502:physiology; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D010802:Phylogeny; D018517:Plant Roots / Q000201:enzymology; D021382:Protein Sorting Signals / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000201:enzymology* / Q000235:genetics* / Q000382:microbiology; D013559:Symbiosis
D018076:DNA, Complementary; D018744:DNA, Plant; D006023:Glycoproteins; D007527:Isoenzymes; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D018749:RNA, Plant; D010758:Phosphorus; C091137:purple acid phosphatase; D000135:Acid Phosphatase; D010744:Phosphoric Monoester Hydrolases