Characterization of Arabidopsis Acid Phosphatase Promoter and Regulation of Acid Phosphatase Expression

• Published in: Plant physiology (Bethesda) 2000-10, Vol.124 (2), p.615-626
• Main Authors: Shoshan Haran, Logendra, Sithes, Seskar, Mirjana, Margarita Bratanova, Raskin, Ilya
• Format: Article
• Language: English
• Subjects: Acid Phosphatase - genetics; Analytical, structural and metabolic biochemistry; Arabidopsis - enzymology; Arabidopsis - genetics; Base Sequence; Biological and medical sciences; Brassica - enzymology; Brassica - genetics; Cloning, Molecular; DNA; DNA Primers - genetics; DNA, Plant - genetics; Environmental Stress and Adaptation; Enzymes; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Gels; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Plant; Genes, Plant; Green Fluorescent Proteins; Hydrolases; Hydroponics; Luminescent Proteins - genetics; Metabolism; Molecular Sequence Data; Mustards; Phosphatases; Phosphates; Plant physiology and development; Plant roots; Plants; Plants, Genetically Modified; Promoter regions; Promoter Regions, Genetic; RNA, Plant - genetics; Seedlings
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.124.2.615

The expression and secretion of acid phosphatase (APase) was investigated in Indian mustard (Brassica juncea L. Czern.) plants using sensitive in vitro and activity gel assays. Phosphorus (P) starvation induced two APases in Indian mustard roots, only one of which was secreted. Northern-blot analysis indicated transcriptional regulation of APase expression. Polymerase chain reaction and Southern-blot analyses revealed two APase homologs in Indian mustard, whereas in Arabidopsis, only one APase homolog was detected. The Arabidopsis APase promoter region was cloned and fused to the β-glucuronidase (GUS) and green fluorescent protein (GFP) reporter genes. GUS expression was first evident in leaves of the P-starved Arabidopsis plants. In P-starved roots, the expression of GUS initiated in lateral root meristems followed by generalized expression throughout the root. GUS expression diminished with the addition of P to the medium. Expression of GFP in P-starved roots also initiated in the lateral root meristems and the recombinant GFP with the APase signal peptide was secreted by the roots into the medium. The APase promoter was specifically activated by low P levels. The removal of other essential elements or the addition of salicylic or jasmonic acids, known inducers of gene expression, did not activate the APase promoter. This novel APase promoter may be used as a plant-inducible gene expression system for the production of recombinant proteins and as a tool to study P metabolism in plants.