Catalyzes the first irreversible reaction from fructose-1,6-bisphosphate to fructose-6-phosphate and inorganic phosphate and plays an important regulatory role in sucrose biosynthesis and metabolism. Required for sucrose supply and tiller bud outgrowth. beta-D-fructose 1,6-bisphosphate + H2O = beta-D-fructose 6-phosphate + phosphate Binds 3 Mg(2+) ions per subunit. Homotetramer. Reduced tiller numbers, pale-green leaves, reduced growth rate and dwarf phenotype. In plants there are two FBPase isozymes: one in the cytosol and the other in the chloroplast. Belongs to the FBPase class 1 family.