Essential protein required during embryogenesis, especially in initiating and maintaining the organization of shoot apical meristems (SAMs), cotyledons, and hypocotyls (PubMed:15266054, PubMed:25871650). Involved in auxin-mediated pathways during embryogenesis (PubMed:25871650). RNase that has both endonuclease and 5'-3' exonuclease activities. Involved in RNA surveillance to prevent overaccumulation of antisense RNA (PubMed:22033332). Probably involved in maturation of rRNA and in some organisms also mRNA maturation and/or decay (By similarity). Binds up to 2 Zn(2+) ions per subunit. Homodimer. May be a subunit of the RNA degradosome. Moslty expressed in inflorescences, seedlings, leaves, flowers and flower buds, and, to a lower extent, in stems, siliques and roots. During the early stages of embryo development, first observed at the transition stage. In the heart and torpedo stages, predominantly present in the upper part of embryos. In seedlings, strongly expressed in shoot meristems, hypocotyls, in the vascular bundles of cotyledons, and in the veins of mature leaves. In reproductive organs, detected in inflorescences, especially in sepals, filaments, and stigmas, as well as in mature siliques and seeds. By light. Defective embryo arrested at globular stage (PubMed:15266054, PubMed:25871650). Impaired chloroplast development due to a disturbed formation of internal thylakoid membranes during embryogenesis. Aberrant embryo patterning along the apical-basal axis. Disrupted transport and response of auxin in embryos (PubMed:25871650). Silenced plants exhibit chlorosis and slight disruptions in the cleavage of polycistronic rRNA and mRNA precursors (PubMed:22033332). Belongs to the metallo-beta-lactamase superfamily. RNA-metabolizing metallo-beta-lactamase-like family. Bacterial RNase J subfamily.