Three novel axiomatic theories of grounded truth are presented, each of which is formulated in the language of Peano arithmetic together with unary predicates T(x) and G(x), meaning 'x is true' and 'x is grounded', respectively. (The latter predicate will bedefined in terms of the former.) Each of the systems proposed will share the same truth-theoretic axioms, viz. the compositional axioms relative to G. However, the theories will differ as to which sentences are counted among the grounded ones. The three systems in question are intended as axiomatizations of the following semantical theories of truth: 1. Kripke's miminal fixed-point based on the Strong Kleene evaluation schema (Kripke 1975). 2. Cantini's miminmal fixed-point based on supervaluations (Cantini 1990). 3. Leitgeb's minimial fixed-point based on a notion of semantical dependence (Leitgeb 2005). Leitgeb's theory has not been axiomatized so far. In giving axioms of groundedness also for Kripke's and Cantini's construction we hope to facilitate comparison between the three semantical theories. We assess the proof-theoretic strength of the systems and compare them to the systems KF, VF and Feferman's DT.