27YLU75U4W 330-13-2 4-MU 4-MUP 4-methylumbelliferone 4-methylumbelliferone phosphate APase Acid Phosphatase Acid phosphatase CRs Cluster roots Comparative Study EC 3.1.3.2 ELF-97 Fluorescent Dyes Fluorescent labelling Journal Article Nitrophenols Organophosphorus Compounds P Phosphorus Phosphorus deficiency Pi Plant Proteins Research Support, Non-U.S. Gov't White lupin acid phosphatase cluster roots enzyme-labelled fluorescence-97 nitrophenylphosphate